TGE华毒强、弱毒株的全基因组分子差异及基于BAC反向遗传系统的初探
|
摘要
猪传染性胃肠炎(Porcine transmissible gastroenteritis, TGE)是由猪传染性胃肠炎病毒(Porcine transmissible gastroenteritis virus, TGEV)引起的一种高度接触传染性肠道疾病,以引起一周龄以下仔猪呕吐、水样腹泻和高死亡率(通常为100 %)为主要特征。TGEV主要感染仔猪的小肠上皮细胞,从而最终导致发生致死性的腹泻。近几十年来,各种不同毒力的TGEV已经被各国的研究人员成功分离,同时对其特性进行了详细的研究。一些现地分离的强毒株在长期的体外培养过程中其毒力逐渐降低,并且被培育成优良的弱毒疫苗株。我国马思奇等人成功培育了我国TGE华毒弱毒株。该弱毒株是由TGE华毒强毒株经过5次蚀斑克隆、经PK-15细胞系体外连续培养165代培育而成。目前已广泛应用于我国TGE的防控中。至今为止,TGE华毒弱毒株作为我国具有独立自主知识产权的优秀疫苗株其完整的全基因组背景目前仍不清楚,其分子致弱机制更不清楚,因此,亟待完成TGE华毒强、弱毒株的全基因组的序列测定工作,其全基因组序列的完成将为我国TGE的防控提供分子基础。本研究首先通过常规的RT-PCR方法分别克隆完成了我国TGE华毒强、弱毒株的全基因组序列(登录号分别为:FJ755618和EU074218)。TGE华毒强、弱毒株的全基因组序列全长均为28, 569 bp(包含30 bp的poly(A)尾巴)。序列分析发现:在长期的体外培养传代过程中,TGE华毒弱毒株在序列组成上没有插入、缺失等现象发生,只存在27个核苷酸的突变,最终导致16个氨基酸发生突变。因此,我们得出结论:氨基酸的突变是导致TGE华毒强毒株致弱的原因。
迄今为止,GenBank数据库中只有3对TGEV强弱毒株完整的全基因组序列存在,研究发现,国外的Miller M6强毒株在长期的体外传代致弱过程中,其基因3基因片段存在缺失;而我国TGE华毒强毒株和国外Purdue强毒株在长期的体外传代过程中,在该部位未发现存在缺失现象。同时,不同毒力的TGEV毒株在S基因和(或)基因3区域往往存在大片段的缺失或插入现象。然而至今没有关于我国TGEV毒株基因3基因片段的相关研究报道。本研究通过建立的RT-PCR方法对我国部分现地TGEV毒株的基因3的基因片段进行检测,结果显示:我国现地TGEV毒株基因3存在较大差异,其中,CH/SDQ/08毒株的3a基因其ATG上游的31个碱基以及包含ATG在内的50个碱基发生缺失;CH/JLY1/08的3a基因起始密码子ATG突变为ACG,导致CH/JLY1/08毒株不能形成完整的ORF 3a。CH/JLY1/08的3b基因的终止密码子TAG突变为TTT,导致其3b基因出现了移码突变,与其它毒株相比多了7个氨基酸。同时,同一猪群中存在多种不同基因型TGEV毒株的感染。
通过对TGE华毒强、弱毒株的全基因组序列及GenBank数据库中登录的所有相关TGEV毒株的基因序列进行分析比较发现:TGE华毒弱毒株在全基因组序列上存在6个独有的核苷酸突变(G6014TORF1a、T12388CORF1b、T21937CS、T21969AS、A26025CE,和C27507TN),可以作为区分TGE疫苗株与现地野毒感染的分子标签。本研究针对TGEV N基因核苷酸突变(C27507TN)所产生的Acl I限制性内切酶位点分子标签建立了区分TGEV疫苗免疫和野毒感染的RT-PCR-RFLP鉴别诊断方法。利用建立的RT-PCR-RFLP鉴别诊断方法对我国部分现地TGEV毒株的N基因片段进行检测,结果显示:我国现地TGEV毒株处于不断的遗传演化中,现地TGEV毒株分为3个群:不同群中的TGEV毒株N基因差异较大,与以往报道的TGEV毒株相比,9株我国现地TGEV毒株形成一个独立的新群。
本研究所中所采用的TGE华毒弱毒株是由本实验室成功培育的弱毒株,具有安全、稳定、免疫原性好和遗传背景清楚等特点,为了阐述我国TGE华毒强毒株致弱的分子机制,本研究拟希望采用西班牙马德里大学的Luis Enjuanes教授馈赠的pBAC-5`- 3`载体为骨架构建我国TGE华毒弱毒株的反向遗传系统。目前,我们已经在对TGE华毒弱毒株全基因组序列的第3,012位和26,925位的Pml I位点、第24,699位的ApaLI位点进行了无义突变的基础上,构建完成了涵盖TGE华毒弱毒株全基因组的5个中间质粒(A、B、C、D和E中间质粒);同时已经将获得准确的序列E、A和B质粒(大约14 Kb)依次亚克隆到pBAC载体中,下游的工作还在继续进行当中。
Porcine transmissible gastroenteritis virus (TGEV) was initially identified as the etiological agent of transmissible gastroenteritis (TGE) in swine in 1946 in the United States. In neonates, TGEV infects the epithelial cells of the small intestines, leading to potentially fatal gastroenteritis. The virus can also lead to infection in the upper respiratory tract and less often, in the lungs. In adults, TGEV causes mild disease. In swine, it is the major cause of viral enteritis and fetal diarrhea in neonates, resulting in significant economic losses. TGEV was reported in many swine-producing countries between the late 1980s and the 1990s. TGEV strains of varying virulence have been isolated and characterized worldwide. Some strains have been used to develop modified live vaccines with limited success. In China, a TGE outbreak was first reported in the 1970s. Since then it has been prevalent in many provinces and has become one of the most important viral diarrhea diseases in China. The Chinese TGEV vaccine strain H165 was derived from a virulent field strain H16 by 165 passages in PK15 cells. Vaccines based on the H165 strain are currently commercially available to prevent and control TGEV infections in China. H165 virus was proven to be safe in piglets and pregnant sows and efficacious against TGEV infection. Whole genome sequences of strains H165 and H16 will help us to understand the genetic basis of TGEV attenuation and enhance the geographic differentiation information among TGEV strains.
Up to now, there were only seven TGEV strains and one PRCV strain PRCV-ISU-1 had been fully sequenced, though partial sequences of TGEV strains were available in the GenBank. Moreover, only two virulent and attenuated TGEV pairs were reported with difference in the gene 3 region. Previously studies have shown that there is a genetic diversity in the genomes of TGEV, especially in the gene 3. However, this report is a first one dealing with the genetic diversity in the gene 3 of Chinese field TGEV strains and reference TGEV strains. Our findings showed that 8 Chinese TGEV strains were genetically diverse in the gene 3 among themselves as well as in comparison with the reference strains. The nucleotide sequence data revealed genetic diversity in the gene 3 region of the Chinese field TGEV strains, even though the viruses were isolated from the same place. These results also indicated that different strains were present in the same farm.
There were a total of 27 nt mutations identified in strain H165, resulting in a total of 16 aa mutations mainly located within proteins 1a, 1ab, S, 3a, 3b, and E. Furthermore, six nt mutations (G6014TORF1a, T12388CORF1b, T21937CS, T21969AS, A26025CE, and C27507TN) could be the makers used to differentiate the Chinese vaccine strain from other strains of TGEV in the GenBank. Vaccines based on passages 155 to 165 in cell cultures are available commercially as vaccines for the prevention and control of infections with TGEV in China. Nucleoprotein (N) sequences of the virus at passages 155 and 165 were aligned and compared using a computer software program. The suitability of restriction fragment length polymorphism (RFLP) analysis for differentiation of the vaccine strain from the other TGEVs was investigated. The RFLP analysis identified a change in the cleavage sites of Acl I at passages 155 and 165. This RFLP pattern of the N gene differentiated the Chinese vaccine strain from its parental strain, the TGEVs studied and the other reported TGEVs in the GenBank. Phylogenetic and sequence analysis results showed that the Chinese TGEVs were divided into three groups with several specific nucleotides and amino acids among them. These findings suggest that Chinese strains of TGEV are evolving continuously.
In order to determine the genetic basis of TGEV attenuation for virulent H, we would like to construction the reverse genetics system based on the pBAC-5`- 3` vector, which was kindly provided by the Prof. Luis Enjuanes in Campus Universidad Autonoma. Five Intermediate vector plasmid with the corrected sequences were prepared to insert into the pBAC-5`- 3` vector. Up to now, three fragments had been inserted into the vector, In order to construct the reverse genetics system of attenuated H, it is necessary to insert the left two fragments into the vector in the following study.
迄今为止,GenBank数据库中只有3对TGEV强弱毒株完整的全基因组序列存在,研究发现,国外的Miller M6强毒株在长期的体外传代致弱过程中,其基因3基因片段存在缺失;而我国TGE华毒强毒株和国外Purdue强毒株在长期的体外传代过程中,在该部位未发现存在缺失现象。同时,不同毒力的TGEV毒株在S基因和(或)基因3区域往往存在大片段的缺失或插入现象。然而至今没有关于我国TGEV毒株基因3基因片段的相关研究报道。本研究通过建立的RT-PCR方法对我国部分现地TGEV毒株的基因3的基因片段进行检测,结果显示:我国现地TGEV毒株基因3存在较大差异,其中,CH/SDQ/08毒株的3a基因其ATG上游的31个碱基以及包含ATG在内的50个碱基发生缺失;CH/JLY1/08的3a基因起始密码子ATG突变为ACG,导致CH/JLY1/08毒株不能形成完整的ORF 3a。CH/JLY1/08的3b基因的终止密码子TAG突变为TTT,导致其3b基因出现了移码突变,与其它毒株相比多了7个氨基酸。同时,同一猪群中存在多种不同基因型TGEV毒株的感染。
通过对TGE华毒强、弱毒株的全基因组序列及GenBank数据库中登录的所有相关TGEV毒株的基因序列进行分析比较发现:TGE华毒弱毒株在全基因组序列上存在6个独有的核苷酸突变(G6014TORF1a、T12388CORF1b、T21937CS、T21969AS、A26025CE,和C27507TN),可以作为区分TGE疫苗株与现地野毒感染的分子标签。本研究针对TGEV N基因核苷酸突变(C27507TN)所产生的Acl I限制性内切酶位点分子标签建立了区分TGEV疫苗免疫和野毒感染的RT-PCR-RFLP鉴别诊断方法。利用建立的RT-PCR-RFLP鉴别诊断方法对我国部分现地TGEV毒株的N基因片段进行检测,结果显示:我国现地TGEV毒株处于不断的遗传演化中,现地TGEV毒株分为3个群:不同群中的TGEV毒株N基因差异较大,与以往报道的TGEV毒株相比,9株我国现地TGEV毒株形成一个独立的新群。
本研究所中所采用的TGE华毒弱毒株是由本实验室成功培育的弱毒株,具有安全、稳定、免疫原性好和遗传背景清楚等特点,为了阐述我国TGE华毒强毒株致弱的分子机制,本研究拟希望采用西班牙马德里大学的Luis Enjuanes教授馈赠的pBAC-5`- 3`载体为骨架构建我国TGE华毒弱毒株的反向遗传系统。目前,我们已经在对TGE华毒弱毒株全基因组序列的第3,012位和26,925位的Pml I位点、第24,699位的ApaLI位点进行了无义突变的基础上,构建完成了涵盖TGE华毒弱毒株全基因组的5个中间质粒(A、B、C、D和E中间质粒);同时已经将获得准确的序列E、A和B质粒(大约14 Kb)依次亚克隆到pBAC载体中,下游的工作还在继续进行当中。
Porcine transmissible gastroenteritis virus (TGEV) was initially identified as the etiological agent of transmissible gastroenteritis (TGE) in swine in 1946 in the United States. In neonates, TGEV infects the epithelial cells of the small intestines, leading to potentially fatal gastroenteritis. The virus can also lead to infection in the upper respiratory tract and less often, in the lungs. In adults, TGEV causes mild disease. In swine, it is the major cause of viral enteritis and fetal diarrhea in neonates, resulting in significant economic losses. TGEV was reported in many swine-producing countries between the late 1980s and the 1990s. TGEV strains of varying virulence have been isolated and characterized worldwide. Some strains have been used to develop modified live vaccines with limited success. In China, a TGE outbreak was first reported in the 1970s. Since then it has been prevalent in many provinces and has become one of the most important viral diarrhea diseases in China. The Chinese TGEV vaccine strain H165 was derived from a virulent field strain H16 by 165 passages in PK15 cells. Vaccines based on the H165 strain are currently commercially available to prevent and control TGEV infections in China. H165 virus was proven to be safe in piglets and pregnant sows and efficacious against TGEV infection. Whole genome sequences of strains H165 and H16 will help us to understand the genetic basis of TGEV attenuation and enhance the geographic differentiation information among TGEV strains.
Up to now, there were only seven TGEV strains and one PRCV strain PRCV-ISU-1 had been fully sequenced, though partial sequences of TGEV strains were available in the GenBank. Moreover, only two virulent and attenuated TGEV pairs were reported with difference in the gene 3 region. Previously studies have shown that there is a genetic diversity in the genomes of TGEV, especially in the gene 3. However, this report is a first one dealing with the genetic diversity in the gene 3 of Chinese field TGEV strains and reference TGEV strains. Our findings showed that 8 Chinese TGEV strains were genetically diverse in the gene 3 among themselves as well as in comparison with the reference strains. The nucleotide sequence data revealed genetic diversity in the gene 3 region of the Chinese field TGEV strains, even though the viruses were isolated from the same place. These results also indicated that different strains were present in the same farm.
There were a total of 27 nt mutations identified in strain H165, resulting in a total of 16 aa mutations mainly located within proteins 1a, 1ab, S, 3a, 3b, and E. Furthermore, six nt mutations (G6014TORF1a, T12388CORF1b, T21937CS, T21969AS, A26025CE, and C27507TN) could be the makers used to differentiate the Chinese vaccine strain from other strains of TGEV in the GenBank. Vaccines based on passages 155 to 165 in cell cultures are available commercially as vaccines for the prevention and control of infections with TGEV in China. Nucleoprotein (N) sequences of the virus at passages 155 and 165 were aligned and compared using a computer software program. The suitability of restriction fragment length polymorphism (RFLP) analysis for differentiation of the vaccine strain from the other TGEVs was investigated. The RFLP analysis identified a change in the cleavage sites of Acl I at passages 155 and 165. This RFLP pattern of the N gene differentiated the Chinese vaccine strain from its parental strain, the TGEVs studied and the other reported TGEVs in the GenBank. Phylogenetic and sequence analysis results showed that the Chinese TGEVs were divided into three groups with several specific nucleotides and amino acids among them. These findings suggest that Chinese strains of TGEV are evolving continuously.
In order to determine the genetic basis of TGEV attenuation for virulent H, we would like to construction the reverse genetics system based on the pBAC-5`- 3` vector, which was kindly provided by the Prof. Luis Enjuanes in Campus Universidad Autonoma. Five Intermediate vector plasmid with the corrected sequences were prepared to insert into the pBAC-5`- 3` vector. Up to now, three fragments had been inserted into the vector, In order to construct the reverse genetics system of attenuated H, it is necessary to insert the left two fragments into the vector in the following study.
引文
1.李丹丹,田志军,姜骞,唐丽杰,李一经. (2006).应用TGEV N蛋白McAb间接免疫荧光法检测TGEV的研究.中国兽医杂志, 42, 14–15.
2.刘光清,刘在新,谢庆阁. (2003). RNA病毒感染性克隆的构建原理及应用.生命的化学, 23, 17-320.
3.马思奇,王明,王玉春,魏凤祥,董齐,于文涛,等(1985).猪传染性胃肠炎弱毒株的培育.中国预防兽医学报, 23, 4–10.
4.孙东波,冯力,时洪艳,刘胜旺,陈洪岩,佟有恩,等(2006).猪传染性胃肠炎病毒重组N蛋白抗原间接ELISA抗体检测方法的建立.中国预防兽医学报, 28, 572–576.
5.王树成,赵祥平. (1997).二种方法检测猪传染性胃肠炎病毒抗体的比较.中国畜禽传染病, 2, 31–33.
6.翁崇鹏,张莉,毛娅卿,何后军. (2004).猪传染性胃肠炎病毒N蛋白基因的克隆及其原核表达载体的构建.江西农业大学学报, 26, 576–580.
7.张炳丽,唐丽杰,范京慧,王玉玲,边亚娟,钟涛,等(2006).猪传染性胃肠炎S基因A、D抗原位点在昆虫杆状病毒系统中的表达.中国兽医杂志, 42, 22–24.
8.张素芳,何孔旺,贾云,倪艳秀,华荣虹,赵玉军. (2003).猪传染性胃肠炎病毒南京株纤突蛋白基因的克隆与序列分析.动物医学进展, 24, 93–97.
9.钟涛,唐丽杰,李一经,师东方,王术德,高慧江. (2007).间接竞争ELISA检测TGEV方法的建立.中国兽医杂志, 43, 20–21.
10.周仲芳,李力复,罗长保,陈茹,鱼海琼. (2000).利用重组抗原建立间接酶联免疫吸附试验检测猪传染性胃肠炎血清抗体.中国兽医杂志, 26, 12–14.
11. Almazan, F., Gonzalez, J. M., Penzes, Z., Izeta, A., Calvo, E., Plana-Duran, J., et al. (2000). Engineering the largest RNA virus genome as an infectious bacterial chromosome. Proc. Natl. Acad. Sci., 76, 5516–5521.
12. Alonso, S., Izeta, A., Sola, I., & Enjuanes. L. (2002). Transcription regulatory sequences and mRNA expression levels in the coronavirus transmissible gastroenteritis virus. J. Virol., 76, 1293–1308.
13. Anand, K., Palm, G. J., Mesters, J. R., Siddell, S. G., Ziebuhr, J., & Hilgenfeld, R. (2002). Structure of coronavirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-helical domain. EMBO J., 21, 3213–3224.
14. Anand, K., Ziebuhr, J., Wadhwani, P., Mesters, J. R., & Hilgenfeld, R. (2003). Coronavirus main proteinase (3CLpro) structure: basis for design of anti-SARS drugs. Science, 300, 1763–1767.
15. Ballesteros, M. L., Sanchez, C. M., & Enjuanes, L. (1997). Two amino acid changes at the N-terminal of the transmissible gastroenteritis coronavirus spike protein result in the loss of enterictropism. Virology, 227, 378–388.
16. Ballesteros, M. L., Sanchez, C. M., Martin-Caballero, J., & Enjuanes, L. (1995). Molecular bases of tropism in the PUR46 cluster of transmissible gastroenteritis coronaviruses. Adv. Exp. Med. Biol., 380, 557–562.
17. Benfield, D. A., Jackwood, D. J., Bac, I., Saif, L. J., & Wesley, R. D. (1991). Detection of transmissible gastroenteritis virus using cDNA probes. Arch. Virol., 116, 91–106.
18. Bernard, S., & Laude, H. (1995). Site-specific alteration of transmissible gastroenteritis virus spike protein results in markedly reduced pathogenicity. J. Gen. Virol., 76, 2235–2241.
19. Bonilla, P. J., Gorbalenya, A. E., & Weiss, S. R. (1994). Mouse hepatitis virus strain A59 RNA polymerase gene ORF 1a: heterogeneity among MHV strains. Virology, 198, 736–740.
20. Bosch, B. J., Martina, B. E., Van Der Zee, R., Lepault, J., Haijema, B. J., Versluis, C., et al. (2004). Severe acute respiratory syndrome coronavirus (SARS-CoV) infection inhibition using spike protein heptad repeat-derived peptides. Proc. Natl. Acad. Sci., 101, 8455–8460.
21. Boyer, J., Haenni, A. (1994). Infectious Transcripts and cDNA clones of RNA virus. Virology, 198, 415–426.
22. Bredenbeek, P. J., Pachuk, C. J., Noten, A. F., Charite, J., Luytjes, W., Weiss, S. R., et al. (1990). The primary structure and expression of the second open reading frame of the polymerase gene of the coronavirus MHV-A59; a highly conserved polymerase is expressed by an efficient ribosomal frameshifting mechanism. Nucleic. Acids. Res., 18, 1825–1832.
23. Brian, D. A., & Baric, R. S. (2005). Coronavirus genome structure and replication. Curr. Top. Microbiol. Immunol., 287, 1–30.
24. Brierley, I. (1995). Ribosomal frameshifting viral RNAs. J. Gen. Virol., 76, 1885–1892.
25. Brown, T.D.K., & Brierley, I. (1995). The coronavirus nonstructural proteins. In The Coronaviridae (S.G. Siddell, ed.), Plenum Press. New York and London. pp. 191–217.
26. Calvo, E., Escors, D., López, J. A., González, J. M.,álvarez, A., Arza, E., et al. (2005). Phosphorylation and subcellular localization of transmissible gastroenteritis virus nucleocapsid protein in infected cells. J. Gen. Virol., 86, 2255–2267
27. Carbrey, E. A., Stewart, W. C., & Kresse, J. I. (1969). Confirmation of hog cholera diagnosis by rapid serum-neutralization technique. J. Am. Vet. Med. Ass., 155, 2201–2210.
28. Carman, S., Josephson, G., & McEwen, B. (2002). Field Validation of a Commercial Blocking ELISA to Differentiate antibody to Transmissible Gastroenteritis Virus (TGEV) and Porcine Respiratory Coronavirus and to Identify TGEV-infected Swine Herds. J. Vet. Diagn. Invest., 14, 97–105.
29. Casais, R., Thiel, V., Siddell, S. G., Cavanagh, D., & Britton. P. (2001). Reverse genetics system forthe avian coronavirus infectious bronchitis virus. J. Virol., 214, 916–919.
30. Chen, C. M., Cavanagh, D., & Britton, P. (1995). Cloning and sequencing of a 8.4-kb region from the 3′-end of a Taiwanese virulent isolate of the coronavirus transmissible gastroenteritis virus. Virus. Res., 38, 83–89.
31. Chen, R., Huang, W., Lin, Z., Zhou, Z., Yu, H., & Zhu, D. (2004). Development of a novel real-time RT-PCR assay with LUX primer for the detection of swine transmissible gastroenteritis virus. J. Virol. Methods., 122, 57–61.
32. Chua, M. M., MacNamara, K. C., San Mateo, L., Shen, H., & Weiss. S. R. (2004). Effects of an epitope-specific CD8+ T-cell response on murine coronavirus central nervous system disease: protection from virus replication and antigen spread and selection of epitope escape mutants. J. Virol., 78, 1150–1159.
33. Coley, S. E., Lavi, E., Sawicki, S. G., Fu, L., Schelle, B., Karl, N., et al. (2005). Recombinant mouse hepatitis virus strain A59 from cloned, full-length cDNA replicates to high titers in vitro and is fully pathogenic in vivo. J. Virol., 79, 53097–3106.
34. Curtis, K. M., Yount, B., & Baric, R. S. (2002). Heterologous gene expression from transmissible gastroenteritis virus replicon particles. J. Virol., 76, 1422–1434.
35. Daniel, C., Anderson, R., Buchmeier, M. J., Fleming, J. O., Spaan, W. J., Wege, H., et al. (1993). Identification of an immunodominant linear neutralization domain on the S2 portion of the murine coronavirus spike glycoprotein and evidence that it forms part of complex tridimensional structure. J. Virol., 67, 1185–1194.
36. Das Sarma, J., Fu, L., Tsai, J. C., Weiss, S. R., & Lavi, E. (2000). Demyelination determinants map to the spike glycoprotein gene of coronavirus mouse hepatitis virus. J. Viro., 74, 9206–9213.
37. De Haan, C. A. M., Masters, P. S., Shen, X., Weiss, S., & Rottier, P. J. M. (2002). The group-specific murine coronavirus genes are not essential, but their deletion, by reverse genetics, is attenuating in the natural host. Virology, 296, 177–189.
38. De Haan, C. A. M., van Genne, L., Stoop, J. N., Volders, H., & Rottier, J. M. P. (2003). Coronaviruses as vectors: position dependence of foreign gene expression. J. Virol., 77, 11123–11312.
39. De Haan, C. A. M., Volders, H., Koetzner ,C. A., Masters, P. S., & Rottier, P. J. M. (2002). Coronavirus maintain viability despite dramatic rearrangements of the strictly conserved genome organization. J. Virol., 76, 12491–12502.
40. de Vries, A. A. F., Chrinside, E. D., Bredenbeek, P. J., Grave stein, L. A., Horzinek, M. C., & Spaan, W. J. M. (1990). All subgenomic mRNAs of equine arteritis virus contain a common leader sequence. Nucleic Acids Res., 18, 32–41.
41. Delmas, B., Gelfi ,J., L_Haridon, R., Vogel, L. K., Norn, O., & Laude ,H. (1992). AminopeptidaseN is a major receptor for the enteropathogenic coronavirus TGEV. Nature, 357, 417–419.
42. Delmas, B., Rasschaert, D., Godet, M., Gelfi, J., & Laude, H. (1990). Four major antigenic site of the coronavirus transmissible gastroenteritis virus are located on the amino terminal half of spike glycoprotein. J. Gen. Virol., 71, 1313–1323.
43. Doyle, L. P., & Hutchings, L. M. (1946). A transmissible gastroenteritis in pigs. J. Am. Vet. Med. Assoc., 108, 257–259.
44. Doyle, L. P. (1951). Transmissible gastroenteritis of pigs. North Am. Vet., 32, 477–478.
45. Enjuanes, L., Sanchez, C., Gebauer, F., Mendez, A., Dopazo, J., & Ballesteros, M. L. (1993). Evolution and tropism of transmissible gastroenteritis coronavirus. Adv. Exp. Med. Biol., 342, 35–42.
46. Enjuanes, L., Smerdou, C., Castilla, J., Anton, I. M., Torres, J. M., Sola, I., et al. (1995). Development of protection against coronavirus induced diseases. A review. Adv. Exp. Med. Biol., 380, 197–211.
47. Escors, D., Izeta, A., Capiscol, M. C., & Enjuanes, L. (2003). Transmissible gastroenteritis coronavirus packaging signal is located at the 50 end of the virus genome. J. Virol., 77, 7890–902.
48. Escors, D., Ortego, J., & Eniuanes, L. (2001). The membrane M protein carboxy terminal binds to transmissible gastroenteritis coronavirus core and contributes to core stability. J. Virol., 75, 1312–1324.
49. Escutenaire, S., Mohamed, N., Isaksson, M., Thorén, P., Klingeborn, B., Belák, S., et al. (2007). SYBR Green real-time reverse transcription-polymerase chain reaction assay for the generic detection of coronaviruses. Arch. Virol., 152, 41–58.
50. Fernando, A., Gonzalez, J. M., & Zoltan, P. (2000). Engineering the largest RNA virus genome as an infectious bacterial chromosome. Proc. Natl. Acad. Sci., 76, 5516–5521.
51. Fischer, F., Stegen, C. F., Koetzner, C. A., & Masters, P. S. (1997). Analysis of a recombinant mouse hepatitis virus expressing a foreign gene reveals a novel aspect of coronavirus transcription. J. Virol., 71, 5148–5160.
52. Flanagan, E. B., Zamparo, J. M., Ball, L. A., Rodriguez, L., & Wertz, G. W. (2001). Rearrangement of the genes of vesicular stomatitis virus eliminates clinical disease in the natural host: new strategy for vaccine development. J. Virol., 75, 6107– 6114.
53. Galan, A., Enjuanes, L., & Almazan, F. (2005). A point mutation within the replicase gene differentially affects coronavirus genome versus minigenome replication. J. Virol., 79, 15016–15026.
54. Gallagher, T., & Buchmeier, M. J. (2001). Coronavirus spike proteins in viral entry and pathogenesis. Virology, 279, 371–374.
55. Gebauer, F., Posthumus, W. A. P., Correa, I., Su, C., S nchez, C. M., Smerdou, C., et al. (1991).Residues involved in the antigenic sites of transmissible gastroenteritis coronavirus S glycoprotein. Virology, 183, 225–238.
56. Godet, M., Grosclaude, J., Delmas, B., & Laude, H. (1994). Major receptor-binding and neutralization determinants are located within the same domain of the transmissible gastroenteritis virus (coronavirus) spike protein. J. Virol., 68, 8008–8016.
57. Godet, M., Haridon, R. L., Vautherot, J. F., & Laude, H. (1992). TGEV ORF4 encodes a membrane protein that is incorporated into virus. J. Virol., 188, 666–675.
58. Gonz_lez, J. M., Penzes, Z., Almaz_n, F., Calvo, E., & Enjuanes, L. (2002). Stabilization of a fulllength infectious cDNA clone of transmissible gastroenteritis coronavirus by the insertion of an intron. J. Virol., 76, 4655–466.
59. Gorbalenya, A. E. (2001). Big nidovirus genome. When count and order of domains matter. Adv. Exp. Med. Biol., 494, 1–17.
60. Guan, Y., Zheng, B. J., He, Y. Q., Liu, X. L., Zhuang, Z. X., Cheung, C. L., et al. (2003). Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China. Science, 302, 276–278.
61. Haijema, B. J., Volders, H., & Rottier, P. J. (2004). Live, attenuated coronavirus vaccines through the directed deletion of group-specific genes provide protection against feline infectious peritonitis. J. Virol., 78, 3863?3871.
62. Haijema, B. J., Volders, H., & Rottier, P. J. M. (2003). Switching species tropism: an effective way to manipulate the feline coronavirus genome. J. Virol., 77, 4528–4538.
63. Halbur, P. G., Paul, P. S., Vaughn, E. M., & Andrews, J. J. (1993). Experimental reproduction of pneumonia in gnotobiotic pigs with porcine resplratory coronavirus isolate AR310. J. Vet. Diagn. Invest., 5, 184–188.
64. Hodgson, T., & Cavanagh, D. (2006). Neither the RNA nor the proteins of open reading frames 3a and 3b of the coronavirus infectious bronchitis virus are essential for replication. Virology, 80, 296–305.
65. Ivanov, K. A., Hertzig, T., Rozanov, M., Bayer, S., Thiel, V., Gorbalenya, A. E., et al. (2004). Major genetic marker of nidoviruses encodes a replicative endoribonuclease. Proc. Natl. Acad. Sci., 101, 12694–12699.
66. Izeta, A., Smerdou, C., Alonso, S., Penzes, Z., Mndez, A., Plana-Duran, J., et al. (1999). Replication and packaging of transmissible gastroenteritis coronavirusderived synthetic minigenomes. J. Virol., 73, 1535–1545.
67. Jia, W., Karaca, K., Parrish, C. R., & Naqi, S. A. (1995). A novel variant of avian infectious bronchitis virus resulting from recombination among three different strains. Arch. Virol., 140, 259–271.
68. Jung, K., & Chae, C. (2005). RT-PCR-based dot blot hybridization for the detection and differentiation between porcine epidemic diarrhea virus and transmissible gastroenteritis virus in fecal samples using a non-radioactive digoxigenin cDNA probe. J. Virol. Methods., 123, 141–146.
69. Jung, K., Kim, J., Kim, O., Kim, B., & Chae, C. (2003). Differentiation between porcine epidemic diarrhea virus and transmissible gastroenteritis virus in formalin-fixed paraffin-embedded tissues by multiplex RT-nested PCR and comparison with in situ hybridization. J. Virol. Methods., 108, 41–47.
70. Keck, J. G., Soe, L. H., Makino, S., Stohlman, S. A., & Lai, M. M. (1988). RNA recombination of murine coronaviruses: recombination between fusion-positive mouse hepatitis virus A59 and fusion-negative mouse hepatitis virus 2. J. Virol., 62, 1989–1998.
71. Kemeny, L. J., & Woods, R. D. (1977). Quantitative transmissible gastroenteritis virus shedding patterns in lactating sows. Am. J. Vet. Res., 38, 307–310.
72. Kim, B., & Chae, C. (2001). In situ hybridization for the detection of transmissible gastroenteritis virus in pigs and comparison with other methods. Can. J. Vet. Res., 65, 33–37.
73. Kim, L., Chang, K. O., Sestak, K., Parwani, A., & Saif, L. J. (2000). Development of a reverse transcription-nested polymerase chain reaction assay for differential diagnosis of transmissible gastroenteritis virus and porcine respiratory coronavirus from feces and nasal swabs of infected pigs. J. Vet. Diagn. Invest., 12, 385–388.
74. Kim, L., Hayes, J., Lewis, P., Parwani, A. V., Chang, K. O., & Saif, L. J. (2000). Molecular characterization and pathogenesis of transmissible gastroenteritis coronavirus (TGEV) and porcine respiratory coronavirus (PRCV) field isolates co-circulating in a swine herd. Arch. Virol., 145, 1133–1147.
75. Kim, O., Choi, C., Kim, B., & Chae, C. (2000). Detection and differentiation of porcine epidemic diarrhoea virus and transmissible gastroenteritis virus in clinical samples by multiplex RT-PCR. Vet. Rec., 146, 637–640.
76. Kim, S. H., Kim, I. J., Pyo, H. M., Tark, D. S., Song, J. Y., & Hyun, B. H. (2007). Multiplex real-time RT-PCR for the simultaneous detection and quantification of transmissible gastroenteritis virus and porcine epidemic diarrhea virus. J. Virol. Methods., 146, 172–177.
77. Kim, S. J., Han, J. H., & Kwon, H. M. (2003). Partial sequence of the spike glycoprotein gene of transmissible gastroenteritis viruses isolated in Korea. Vet. Microbiol., 94, 195–206.
78. Koetzner, C. A., Parker, M. M., Ricard, C. S., Sturman, L. S., & Masters, P. S. (1992). Repair and mutagenesis of the genome of a deletion mutant of the coronavirus mouse hepatitis virus by targeted RNA recombination. J. Virol., 66, 1841–1848.
79. Kozak, M. (1991). Structural features in eukaryotic mRNAs that modulate the initiation of translation. J. Biol. Chem., 266, 19867–19870.
80. Kristopher, M. C., Boyd, Y., & Ralph, S. B. (2002). Heterologous gene expression from transmissible gastroenteritis virus replicon particles. J. Virol., 76, 1422–1434.
81. Kubo, H., Yamada, Y. K., & Taguchi, F. (1994). Localization of neutralizing epitopes and the receptor-binding site within the amino-terminal 330 amino acids of the murine coronavirus spike protein. J. Virol., 68, 5403–5410.
82. Kuo, L., Godeke, G. J., Raamsman, M. J. B., Masters, P. S., & Rottier, P. J. M. (2000). Retargeting of coronavirus by substitution of the spike glycoprotein ectodomain: crossing the host cell species barrier. J. Virol., 74, 1393–1406.
83. Kwon, H. M., Saif, L. J., & Jackwood, D. J. (1998). Field isolates of transmissible gastroenteritis virus differ at the molecular level from the Miller and Purdue virulent and attenuated strains and from porcine respiratory coronaviruses. J. Vet. Med. Sci., 60, 589–597.
84. Lai, C. H., Welter, M. W., & Welter, L. M. (1995). The use of arms PCR and RFLP analysis in identifying genetic profiles of virulent, attenuated or vaccine strains of TGEV and PRCV. Adv. Exp. Med. Biol., 380, 243–250.
85. Lee, C., Park, C. K., Lyoo, Y. S., & Lee, D. S, (2008). Genetic differentiation of the nucleocapsid protein of Korean isolates of porcine epidemic diarrhoea virus by RT-PCR based restriction fragment length polymorphism analysis. J. Vet., 178, 138–140.
86. Lee, H. J., Shieh, C. K., Gorbalenya, A. E., Koonin, E. V., La Monica, N., Tuler, J., et al. (1991). The complete sequence (22 kilobases) of murine coronavirus gene 1 encoding the putative proteases and RNA polymerase. Virology, 180, 567–582.
87. Liu, S. W., Zhang, Q. X., Chen, J. F., Han, Z. X., Shao, Y. H., Kong, X. G., et al. (2008). Identification of the avian infectious bronchitis coronaviruses with mutations in gene 3. Gene, 412, 12–25.
88. Lomniczi, B. (1977). Biological properties of avian coronavirus RNA. J. Gen. Virol., 36, 531–533.
89. Lowings, P., Laudr, H., & Charley, B. (1997). Discrimination between transmissible gastroenteritis virus isolates. Arch. Virol., 142, 1703–1711.
90. Lu, W., Osorio, F. A., Rhodes, M. B., & Moxley, R. A. (1991). A capture-enzyme immunoassay for rapid diagnosis of transmissible gastroenteritis virus. J. Vet. Diagn. Invest., 3, 119–123.
91. Luo, Z., Matthews, A. M., & Weiss, S. R. (1999). Amino acid substitutions within the leucine zipper domain of the murine coronavirus spike protein cause defects in oligomerization and the ability to induce cell-to-cell fusion. J. Virol., 73, 8152–8159.
92. MacNamara, K. C., Chua, M. M., Nelson, P. T., Shen, H., & Weiss, S. R. (2005). Increased epitope-specific CD8+ T cells prevent murine coronavirus spread to the spinal cord and subsequent demyelination. J. Virol., 79, 3370–3381.
93. Makino, S., Keck, J. G., Stohlman, S. A., & Lai, M. M. (1986). High-frequency RNArecombination of murine coronaviruses. J. Virol., 57, 729–737.
94. Masters, P. S., & Rottier, P. J. (2005). Coronavirus reverse genetics by targeted RNA recombination. Curr. Top. Microbiol. Immunol., 287, 133–159.
95. Masters, P. S. (1999). Reverse genetics of the largest RNA viruses. Adv. Virus. Res., 53, 245–264.
96. Masters, P. S. (2006). The molecular biology of coronaviruses. Adv. Virus Res. 66, 193–292.
97. Matsuyama, S., & Taguchi, F. (2002). Receptor-induced conformational changes of murine coronavirus spike protein. J. Virol., 76, 11819–11826.
98. McGoldrick, A., Lowings , J. P., & Paton , D. J. (1999). Characterisation of a recent virulent transmissible gastroenteritis virus from Britain with a deleted ORF 3a. Arch. Virol., 144, 763–770.
99. McIntosh, K. (1974). Coronaviruses: a comparative review. Curr. Top. Microbiol. Immunol., 63, 85–129.
100. Mirmomeni, M. H., Hughes, P. J., & Stanway, G. (1997). An RNA tertiary structure in the 3' untranslated region of enteroviruses is necessary for efficient replication. J. Virol., 71, 2363–2370.
101. Navas, S., Seo, S. H., Chua, M. M., das Sarma, J., Lavi, E., Hingley, S. T., et al. (2001). Murine coronavirus spike protein determines the ability of the virus to replicate in the liver and cause hepatitis. J. Virol., 75, 2452–2457.
102. Nelsen, C. J., Murtaugh, M. P., & Faaberg, K. S. (1999). Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. J. Virol., 73, 270–280.
103. O_Connor, J. B., & Brian, D. A. (2000). Downstream ribosomal entry for translation of coronaviru TGEV gene 3b. Virology, 269, 172–182.
104. O’Connor, J. B., & Brian, D. A. (1999). The major product of porcine transmissible gastroenteritis virus coronavirus gene 3b is an integral membrane glycoprotein of 31kDa. J. Virol., 256, 152–161.
105. Ortego, J., De Diego, M. L., & Enjuanes, L. (2004). Novel human vector based on coronavirus genomes. Submitted for publication
106. Ortego, J., Sola, I., Almazan, F., Ceriani, J. E., Riquelme, C., Balasch, M., et al. (2003). Transmissible gastroenteritis coronavirus gene 7 is not essential but influences in vivo virus replication and virulence. Virology, 308, 13–22.
107. Ozdarendeli, A., Ku, S., Rochat, S., Senanayake, S. D., & Brian, D. A. (2001). Downstream sequences influence the choice between a naturally occurring noncanonical and closely positioned upstream canonical heptameric fusion motif during bovine coronavirus subgenomic mRNA synthesis. J. Virol., 75, 7362–7374.
108. Park, J. H., Han, J. H., & Kwon, H. M. (2008). Sequence analysis of the ORF 7 region of transmissible gastroenteritis viruses isolated in Korea. Virus Genes, 36, 71–78.
109. Pasternak, A. O., van den Born, E,, Spaan, W. J. M., & Snijder, E. J. (2001). Sequence requirements for RNA strand transfer during nidovirus discontinuous subgenomic RNA synthesis.EMBO. J., 20, 7220–7228.
110. Pasternak, A. O., van den Born, E., Spaan, W. J. M., & Snijder, E. J. (2003). The stability of the duplex between sense and antisense transcription-regulating sequences is a crucial factor in arterivirus subgenomic mRNA synthesis. J. Virol., 77, 1175–1183.
111. Paton, D., & Lowings, P. (1997). Discrimination between transmissible gastroenteritis virus isolates. Arch. Virol., 142, 1703–1711.
112. Paton, D., Ibata, G., Sands, J., & McGoldrick, A. (1997). Detection of transmissible gastroenteritis virus by RT-PCR and differentiation from porcine respiratory coronavirus. J. Virol. Methods., 66, 303–309.
113. Pensaert, M., Callebaut, P., & Vergote, J. (1986). Isolation of a porcine respiratory, non-enteric coronavirus related to transmissible gastroenteritis. Vet. Q., 8, 257–261.
114. Penzes, Z., Gonz_lez, J. M., Calvo, E., Izeta, A., Smerdou, C., Mendez, A., et al. (2001). Complete genome sequence of transmissible gastroenteritis coronavirus PUR46-MAD clone and evolution of the Purdue virus cluster. Virus Genes, 23, 105–118.
115. Phillips, J. J., Chua, M. M., Lavi, E., & Weiss, S. R. (1999). Pathogenesis of chimeric MHV4/ MHV-A59 recombinant viruses: the murine coronavirus spike protein is a major determinant of neurovirulence. J. Virol., 73, 7752–7760.
116. Prentice, E., McAuliffe, J., Lu, X., Subbarao, K., & Denison, M. R. (2004). Identification and characterization of severe acute respiratory syndrome coronavirus replicase proteins. J. Virol., 78, 9977–9986.
117. Pritchard, G. C. (1987). Transmissible gastroenteritis in endemically infected breeding herds of pigs in East Anglia. 1981-85. Vet. Rec ., 120, 226–230.
118. Racaniello, V. R., & Baltimore, D. (1995). Cloned polivirus comlementary DNA is infectious in mammalian(S.G. Siddell, ed.). Plenum Press New York and London. pp. 191–2171.
119. Register, K. B., & Wesley, R. D. (1994). Molecular characterization of attenuated vaccine strains of transmissible gastroenteritis virus. J. Vet. Diagn. Invest., 6, 16–22.
120. Riffault, S., Grosclaude, J., Vayssier, M., Laude, H., & Charley, B. (1997). Reconstitued coronavirus TGEV virosomes lose the virus ability to induce porcine interferon alpha production. Vet. Res., 28, 105–114.
121. Rodák, L., Smíd, B., Nevoránková, Z., Valícek, L., & Smítalová, R. (2005). Use of Monoclonal Antibodies in Blocking ELISA Detection of Transmissible Gastroenteritis Virus in Faeces of Piglets. J. Vet. Med. B. Infect. Dis. Vet. Public. Health., 52, 105–111.
122. Aliper, T. I., Rukhadze, G. G., Sergeev, V. A., & Shcheglova, E. (1988). Development of test systems for immunoenzyme analysis for the detection of the antigen of the transmissible gastroenteritis virus of swine. Vopr. Virusol., 33, 315–319.
123. S_nchez, C. M., Gebauer, F., Su, C., Mndez, A., Dopazo, J., & Enjuanes, L. (1992). Genetic evolution and tropism of transmissible gastroenteritis coronaviruses. Virology, 190, 92– 105.
124. S_nchez, C. M., Izeta, A., S_nchez-Morgado, J. M., Alonso, S., Sola, I., Balasch, M., et al. (1999). Targeted recombination demonstrates that the spike gene of transmissible gastroenteritis coronavirus is a determinant of its enteric tropism and virulence. J. Virol., 73, 7607–7618.
125. Saif, L. J., & Sestak, K. (2006). Transmissible gastroenteritis virus and porcine respiratory coronavirus. In Straw BE, Zimmerman JJ, D’Allaire S, Taylor DJ (Eds.): Diseases of Swine. 9th ed. Blackwell Publishing. Iowa. pp. 489–516.
126. Saif, L. J. (2004). Animal coronaviruses: what can they teach us about the severe acute respiratory syndrome? Rev. Sci. Technol., 23, 643–660.
127. Sanchez, C. M., Gebauer, F., Sune, C., Mendez, A., Dopazo, J., & Enjuanes, L. (1992). Genetic evolution and tropism of transmissible gastroenteritis coronaviruses. Virology, 190, 92–105.
128. Sanchez, C. M., Izeta, A., Sanchez-Morgado, J. M., Alonso, S., Sola, I., Balasch. M., et al. (1999). Targeted Recombination Demonstrates that the Spike Gene of Transmissible Gastroenteritis Coronavirus Is a Determinant of Its Enteric Tropism and Virulence. J. Virol., 73, 7607–7618.
129. Sanchez, C. M., Sola, I., Sanchez-Morgado, J. M., & Enjuanes, L. (2004). The amino terminus of transmissible gastroenteritis coronavirus spike protein dictates the enteric tropism of the virus. J. Virol., 73, 7607–7618.
130. Sarma, D. J., Scheen, E., Seo, S. H., Koval, M., & Weiss, S. R. (2002). Enhanced green fluorescent protein expression may be used to monitor murine coronavirus spread in vitro and in the mouse central nervous system. J. Neurovirol., 8, 381–391.
131. Shen, S., Wen, Z. L., & Liu, D. X. (2003). Emergence of a coronavirus infectious bronchitis virus mutant with a truncated 3b gene: functional characterization of the 3b protein in pathogenesis and replication. Virology, 311, 16–27.
132. Shockley, L. J., Kapke, P. A., Lapps, W., Brian, D. A., Potgieter, L. N., & Woods, R. (1987). Diagnosis of porcine and bovine enteric coronaviruses infections using cloned cDNA probe. J Clin. Microbiol., 25, 1591–1596.
133. Sirinarumitr, T., Paul, P. S., Kluge, J. P., & Halbur, P. G. (1996). In situ hybridization technique for the detection of swine enteric and respiratory coronaviruses transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV), in formalin-fixed paraffin-embedded tissues. J. Vir. Met., 56, 146–160.
134. Snijder, E. J., Bredenbeek, P. J., Dobbe, J. C., Thiel, V., Ziebuhr, J., Poon, L. L., Guan, Y., et al. (2003). Unique and conserved features of genome and proteome of SARS-coronavirus, an early split-off from the coronavirus group 2 lineage. J. Mol. Biol., 331, 991–1004.
135. Sola, I., Alonso, S., Zuniga, S., Balasch, M., Plana-Duran, J., & Enjuanes, L. (2003). Engineeringthe Transmissible Gastroenteritis Virus Genome as an Expression Vector Inducing Lactogenic Immunity. J. Virol., 77, 4357–4369.
136. Sola, L., Alonso, S., & Sanchez, C. (2001). Expression of transcriptional units using transmissible gastroenteritis coronavirus derived minigenomes and full–length cDNA clones. Adv. Exp. Med. Biol., 494, 447–451.
137. Song, D. S., Kang, B. K., Oh, J. S., Ha, G. W., Yang, J. S., Moon, H. J., et al. (2006). Multiplex reverse transcription-PCR for rapid differential detection of porcine epidemic diarrhea virus, transmissible gastroenteritis virus, and porcine group a rotavirus. J. Vet. Diagn. Invest., 18, 278–281.
138. Song, D. S., Yang, J. S., Oh, J. S., Han, J. H., & Park, B. K. (2003). Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF3. Vaccine, 21, 1833–1842.
139. Sperry, S., Kazi, L., Graham, R., Baric, R., Weiss, S., & Denison, M. (2005). Single amino acid substitutions in nonstructural ORF1b-nsp14 and ORF2a 30kDa proteins of the murine coronavirus MHV-A59 are attenuating in mice. J. Virol., 79, 3391–3400.
140. Taguchi, F., Kubo, H., Takahashi, H., & Suzuki, H. (1995). Localization of neurovirulence determinant for rats on the S1 subunit of murine coronavirus JHMV. Virology, 208, 67–74.
141. Taniguchi, T., Palmieri, M., & Weissmann, C. (1978). QB DNA-containing hybrid plasmids giving rise to QB phage formation in the bacterial host. Nature, 274, 223–228.
142. Thiel, V., Herold, J., Schelle, B., & Siddell, S. G. (2001). Infectious RNA transcribed in vitro from a cDNA copy of the human coronavirus genome cloned in vaccinia virus. J. Gen. Virol., 82, 1273–1281.
143. Thiel, V., Ivanov, K. A., Putics,á., Hertzig, T., Schelle, B., Bayer, S., et al. (2003). Mechanisms and enzymes involved in SARS coronavirus genome expression. J. Gen. Virol., 84, 2305–2315.
144. Tyrrell, D. A., Almeida, J. D., Cunningham, C. H., Hofstad, M. S., Hampre, D., Mallucci, L., et al. (1968). Coronavirus. Nature, 220, 650.
145. van Marle. G., Dobbe, J. C., Gultyaev, A. P., Luytjes, W., Spaan, W. J. M., & Snijder, E. J. (1999). Arterivirus discontinuous mRNA transcription is guided by base pairing between sense and antisense transcription-regulating sequences. Proc. Natl. Acad. Sci., 96, 12056–12061.
146. Vaughn, R. M., Halbur, P. G., & Paul, P. S. (1995). Sequence comparison of porcine respiratory coronaviruses isolates reveals heterogeneity in the S, 3, and 3-1 genes. J. Virol., 69, 3176–3184.
147. Vijgen, L., Keyaerts, E., Moes, E., Thoelen, I., Wollants, F., & Lemey, P. (2005). Complete genomic sequence of human coronavirus OC43: molecular clock analysis suggests a relatively recent zoonotic coronavirus transmission event. J. Virol., 79, 1595–1604.
148. Wang, L., Junker, D., & Collisson, E. W. (1993). Evidence of natural recombination within the S1gene of infectious bronchitis virus. Virology, 192, 710–716.
149. Wertz, G. W., Perepelitsa, V. P., & Ball, L. A. (1998). Gene rearrangement attenuates expression and lethality of a nonsegmented negative strand RNA virus. Proc. Natl. Acad. Sci., 95, 3501–3506.
150. Wesley, R., Woods, R., & Cheuny, A. (1990). Genetic basis of the pathogenesis of transmissible gastroenteritis virus. J. Viro1., 64, 4761–476.
151. Wesley, R. D., Cheung, A. K., Michael, D. M., & Woods, R. D. (1989). Nucleotide sequence of coronavirus TGEV genomic RNA: evidence of 3 mRNA species between the peplomer and matrix protein genes. Virus. Res., 13, 87–100.
152. Wesley, R. D., Woods, R. D., & Cheung, A. K. (1991). Genetic analysis of porcine respiratory coronavirus, an attenuated variant of transmissible gastroenteritis virus. J. Virol., 65, 3369–3373.
153. Wesley, R. D., Woods, R. D., Hill, H. T., & Biwer, J. D. (1990). Evidence for a porcine respiratory coronavirus, antigenically similar to transmissible gastroenteritis virus, in the United States. J. Vet. Diagn. Invest., 2, 312–317.
154. Wood, E. N., Pritchard, G. C., & Gibson, E. A. (1981). Transmissible gastroenteritis of pigs. Vet. Rec., 108, 41.
155. Wood, R. D. (2001). Efficiency of a transmissible gastroenteritis coronavirus with an altered ORF3 gene .Can. J. Vet. Res., 65, 28–32.
156. Woods, R. D., & Wesley, R. D. (1986). Immune response in sows given transmissible gastroenteritis virus or canine coronavirus. Am. J. Vet. Res., 47, 1239–1242.
157. Woods, R. D. (1976). Leukocyte-aggregation assay for transmissible gastroenteritis of swine. Am. J. Vet. Res., 37, 1405–1408.
158. Woods, R. D. (1997). Development of PCR-based techniques to identify porcine transmissible gastroenteritis coronavirus isolates. Can. J. Vet. Res., 61, 167–172.
159. Woods, R. D. (2001.) Efficacy of a transmissible gastroenteritis coronavirus with an altered ORF-3 gene. Can. J. Vet. Res., 65, 28–32.
160. Wuru, T., Chen, H., Hoddgson, T., Britton, P., Brooks, G. A., & Hiscox, J. (2001). Localization to the nucleolus is a common feature of coronavirus nucleoproteins and the protein may disrupt host cell division. J. Virol., 75, 9345–9356.
161. Yeager, C. L., Ashmun, R. A., Williams, R. K., Cardellichio, C. B., Shapiro, L. H., Look, A. T., et al. (1992). Human aminopeptidase N is a receptor for human coronavirus 229E. Nature, 357, 420–422.
162. Yin, J. C., Ren, X. F., & Li, Y. J. (2005). Molecular cloning and phylogenetic analysis of ORF7 region of Chinese isolate TH-98 from transmissible gastroenteritis virus. Virus Genes, 30, 395–401.
163. Youn, S., Leibowitz, J. L., & Collisson, E. W. (2005). In vitro assembled, recombinant infectiousbronchitis viruses demonstrate that the 5a open reading frame is not essential for replication. Virology, 332, 206–215.
164. Yount, B., Curtis, K. M., & Baric, R. S. (2000). Strategy for systematic assembly of large RNA and DNA genomes: transmissible gastroenteritis virus model. J. Virol., 74, 10600–10611.
165. Yount, B., Curtis, K. M., Fritz, E. A., Hensley, L. E., Jahrling, P. B., Prentice, E., et al. (2003). Reverse genetics with a full–length infectious cDNA of severe acute respiratory syndrome coronavirus. Proc. Natl. Acad. Sci., 100, 12995–13000.
166. Yount, B., Denison, M. R., Weiss, S. R., & Baric, R. S. (2002). Systematic assembly of a full-length infectious cDNA of mouse hepatitis virus strain A59. J. Virol., 76, 11065–11078.
167. Zelus, B. D., Schickli, J. H., Blau, D. M., Weiss, S. R., & Holmes, K. V. (2003). The N-terminal domain of the murine coronavirus spike glycoprotein determines the CEACAM1 receptor specificity of the virus strain. J. Virol., 77, 830–840.
168. Zhang, X. M., & Liu, R. Z. (2000). Identification of a noncanonical signal for transcription of a novel subgenomic mRNA of mouse hepatitis virus: implication for the mechanism of coronavirus RNA transcription. Virology, 278, 75–85.
169. Zhang, X. S., Hasoksuz, M., Spiro, D., Halpin, R., Wang, S. L., Stollar, S., et al. (2007). Complete genomic sequences, a key residue in the spike protein and deletions in non-structural protein 3b of US strains of the virulent and attenuated coronaviruses, transmissible gastroenteritis virus and porcine respiratory coronavirus. Virology, 358, 424–435.
170. Ziebuhr, J. (2005). The coronavirus replicase. Curr. Top. Microbiol. Immunol. 287, 57–94.
171. Ziebuhr, J., Thiel, V., & Gorbalenya, A. E. (2001). The autocatalytic release of a putative RNA virus transcription factor from its polyprotein precursor involves two paralogous papain-like proteases that cleave the same peptide bond. J. Biol. Chem., 276, 33220–33232.
2.刘光清,刘在新,谢庆阁. (2003). RNA病毒感染性克隆的构建原理及应用.生命的化学, 23, 17-320.
3.马思奇,王明,王玉春,魏凤祥,董齐,于文涛,等(1985).猪传染性胃肠炎弱毒株的培育.中国预防兽医学报, 23, 4–10.
4.孙东波,冯力,时洪艳,刘胜旺,陈洪岩,佟有恩,等(2006).猪传染性胃肠炎病毒重组N蛋白抗原间接ELISA抗体检测方法的建立.中国预防兽医学报, 28, 572–576.
5.王树成,赵祥平. (1997).二种方法检测猪传染性胃肠炎病毒抗体的比较.中国畜禽传染病, 2, 31–33.
6.翁崇鹏,张莉,毛娅卿,何后军. (2004).猪传染性胃肠炎病毒N蛋白基因的克隆及其原核表达载体的构建.江西农业大学学报, 26, 576–580.
7.张炳丽,唐丽杰,范京慧,王玉玲,边亚娟,钟涛,等(2006).猪传染性胃肠炎S基因A、D抗原位点在昆虫杆状病毒系统中的表达.中国兽医杂志, 42, 22–24.
8.张素芳,何孔旺,贾云,倪艳秀,华荣虹,赵玉军. (2003).猪传染性胃肠炎病毒南京株纤突蛋白基因的克隆与序列分析.动物医学进展, 24, 93–97.
9.钟涛,唐丽杰,李一经,师东方,王术德,高慧江. (2007).间接竞争ELISA检测TGEV方法的建立.中国兽医杂志, 43, 20–21.
10.周仲芳,李力复,罗长保,陈茹,鱼海琼. (2000).利用重组抗原建立间接酶联免疫吸附试验检测猪传染性胃肠炎血清抗体.中国兽医杂志, 26, 12–14.
11. Almazan, F., Gonzalez, J. M., Penzes, Z., Izeta, A., Calvo, E., Plana-Duran, J., et al. (2000). Engineering the largest RNA virus genome as an infectious bacterial chromosome. Proc. Natl. Acad. Sci., 76, 5516–5521.
12. Alonso, S., Izeta, A., Sola, I., & Enjuanes. L. (2002). Transcription regulatory sequences and mRNA expression levels in the coronavirus transmissible gastroenteritis virus. J. Virol., 76, 1293–1308.
13. Anand, K., Palm, G. J., Mesters, J. R., Siddell, S. G., Ziebuhr, J., & Hilgenfeld, R. (2002). Structure of coronavirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-helical domain. EMBO J., 21, 3213–3224.
14. Anand, K., Ziebuhr, J., Wadhwani, P., Mesters, J. R., & Hilgenfeld, R. (2003). Coronavirus main proteinase (3CLpro) structure: basis for design of anti-SARS drugs. Science, 300, 1763–1767.
15. Ballesteros, M. L., Sanchez, C. M., & Enjuanes, L. (1997). Two amino acid changes at the N-terminal of the transmissible gastroenteritis coronavirus spike protein result in the loss of enterictropism. Virology, 227, 378–388.
16. Ballesteros, M. L., Sanchez, C. M., Martin-Caballero, J., & Enjuanes, L. (1995). Molecular bases of tropism in the PUR46 cluster of transmissible gastroenteritis coronaviruses. Adv. Exp. Med. Biol., 380, 557–562.
17. Benfield, D. A., Jackwood, D. J., Bac, I., Saif, L. J., & Wesley, R. D. (1991). Detection of transmissible gastroenteritis virus using cDNA probes. Arch. Virol., 116, 91–106.
18. Bernard, S., & Laude, H. (1995). Site-specific alteration of transmissible gastroenteritis virus spike protein results in markedly reduced pathogenicity. J. Gen. Virol., 76, 2235–2241.
19. Bonilla, P. J., Gorbalenya, A. E., & Weiss, S. R. (1994). Mouse hepatitis virus strain A59 RNA polymerase gene ORF 1a: heterogeneity among MHV strains. Virology, 198, 736–740.
20. Bosch, B. J., Martina, B. E., Van Der Zee, R., Lepault, J., Haijema, B. J., Versluis, C., et al. (2004). Severe acute respiratory syndrome coronavirus (SARS-CoV) infection inhibition using spike protein heptad repeat-derived peptides. Proc. Natl. Acad. Sci., 101, 8455–8460.
21. Boyer, J., Haenni, A. (1994). Infectious Transcripts and cDNA clones of RNA virus. Virology, 198, 415–426.
22. Bredenbeek, P. J., Pachuk, C. J., Noten, A. F., Charite, J., Luytjes, W., Weiss, S. R., et al. (1990). The primary structure and expression of the second open reading frame of the polymerase gene of the coronavirus MHV-A59; a highly conserved polymerase is expressed by an efficient ribosomal frameshifting mechanism. Nucleic. Acids. Res., 18, 1825–1832.
23. Brian, D. A., & Baric, R. S. (2005). Coronavirus genome structure and replication. Curr. Top. Microbiol. Immunol., 287, 1–30.
24. Brierley, I. (1995). Ribosomal frameshifting viral RNAs. J. Gen. Virol., 76, 1885–1892.
25. Brown, T.D.K., & Brierley, I. (1995). The coronavirus nonstructural proteins. In The Coronaviridae (S.G. Siddell, ed.), Plenum Press. New York and London. pp. 191–217.
26. Calvo, E., Escors, D., López, J. A., González, J. M.,álvarez, A., Arza, E., et al. (2005). Phosphorylation and subcellular localization of transmissible gastroenteritis virus nucleocapsid protein in infected cells. J. Gen. Virol., 86, 2255–2267
27. Carbrey, E. A., Stewart, W. C., & Kresse, J. I. (1969). Confirmation of hog cholera diagnosis by rapid serum-neutralization technique. J. Am. Vet. Med. Ass., 155, 2201–2210.
28. Carman, S., Josephson, G., & McEwen, B. (2002). Field Validation of a Commercial Blocking ELISA to Differentiate antibody to Transmissible Gastroenteritis Virus (TGEV) and Porcine Respiratory Coronavirus and to Identify TGEV-infected Swine Herds. J. Vet. Diagn. Invest., 14, 97–105.
29. Casais, R., Thiel, V., Siddell, S. G., Cavanagh, D., & Britton. P. (2001). Reverse genetics system forthe avian coronavirus infectious bronchitis virus. J. Virol., 214, 916–919.
30. Chen, C. M., Cavanagh, D., & Britton, P. (1995). Cloning and sequencing of a 8.4-kb region from the 3′-end of a Taiwanese virulent isolate of the coronavirus transmissible gastroenteritis virus. Virus. Res., 38, 83–89.
31. Chen, R., Huang, W., Lin, Z., Zhou, Z., Yu, H., & Zhu, D. (2004). Development of a novel real-time RT-PCR assay with LUX primer for the detection of swine transmissible gastroenteritis virus. J. Virol. Methods., 122, 57–61.
32. Chua, M. M., MacNamara, K. C., San Mateo, L., Shen, H., & Weiss. S. R. (2004). Effects of an epitope-specific CD8+ T-cell response on murine coronavirus central nervous system disease: protection from virus replication and antigen spread and selection of epitope escape mutants. J. Virol., 78, 1150–1159.
33. Coley, S. E., Lavi, E., Sawicki, S. G., Fu, L., Schelle, B., Karl, N., et al. (2005). Recombinant mouse hepatitis virus strain A59 from cloned, full-length cDNA replicates to high titers in vitro and is fully pathogenic in vivo. J. Virol., 79, 53097–3106.
34. Curtis, K. M., Yount, B., & Baric, R. S. (2002). Heterologous gene expression from transmissible gastroenteritis virus replicon particles. J. Virol., 76, 1422–1434.
35. Daniel, C., Anderson, R., Buchmeier, M. J., Fleming, J. O., Spaan, W. J., Wege, H., et al. (1993). Identification of an immunodominant linear neutralization domain on the S2 portion of the murine coronavirus spike glycoprotein and evidence that it forms part of complex tridimensional structure. J. Virol., 67, 1185–1194.
36. Das Sarma, J., Fu, L., Tsai, J. C., Weiss, S. R., & Lavi, E. (2000). Demyelination determinants map to the spike glycoprotein gene of coronavirus mouse hepatitis virus. J. Viro., 74, 9206–9213.
37. De Haan, C. A. M., Masters, P. S., Shen, X., Weiss, S., & Rottier, P. J. M. (2002). The group-specific murine coronavirus genes are not essential, but their deletion, by reverse genetics, is attenuating in the natural host. Virology, 296, 177–189.
38. De Haan, C. A. M., van Genne, L., Stoop, J. N., Volders, H., & Rottier, J. M. P. (2003). Coronaviruses as vectors: position dependence of foreign gene expression. J. Virol., 77, 11123–11312.
39. De Haan, C. A. M., Volders, H., Koetzner ,C. A., Masters, P. S., & Rottier, P. J. M. (2002). Coronavirus maintain viability despite dramatic rearrangements of the strictly conserved genome organization. J. Virol., 76, 12491–12502.
40. de Vries, A. A. F., Chrinside, E. D., Bredenbeek, P. J., Grave stein, L. A., Horzinek, M. C., & Spaan, W. J. M. (1990). All subgenomic mRNAs of equine arteritis virus contain a common leader sequence. Nucleic Acids Res., 18, 32–41.
41. Delmas, B., Gelfi ,J., L_Haridon, R., Vogel, L. K., Norn, O., & Laude ,H. (1992). AminopeptidaseN is a major receptor for the enteropathogenic coronavirus TGEV. Nature, 357, 417–419.
42. Delmas, B., Rasschaert, D., Godet, M., Gelfi, J., & Laude, H. (1990). Four major antigenic site of the coronavirus transmissible gastroenteritis virus are located on the amino terminal half of spike glycoprotein. J. Gen. Virol., 71, 1313–1323.
43. Doyle, L. P., & Hutchings, L. M. (1946). A transmissible gastroenteritis in pigs. J. Am. Vet. Med. Assoc., 108, 257–259.
44. Doyle, L. P. (1951). Transmissible gastroenteritis of pigs. North Am. Vet., 32, 477–478.
45. Enjuanes, L., Sanchez, C., Gebauer, F., Mendez, A., Dopazo, J., & Ballesteros, M. L. (1993). Evolution and tropism of transmissible gastroenteritis coronavirus. Adv. Exp. Med. Biol., 342, 35–42.
46. Enjuanes, L., Smerdou, C., Castilla, J., Anton, I. M., Torres, J. M., Sola, I., et al. (1995). Development of protection against coronavirus induced diseases. A review. Adv. Exp. Med. Biol., 380, 197–211.
47. Escors, D., Izeta, A., Capiscol, M. C., & Enjuanes, L. (2003). Transmissible gastroenteritis coronavirus packaging signal is located at the 50 end of the virus genome. J. Virol., 77, 7890–902.
48. Escors, D., Ortego, J., & Eniuanes, L. (2001). The membrane M protein carboxy terminal binds to transmissible gastroenteritis coronavirus core and contributes to core stability. J. Virol., 75, 1312–1324.
49. Escutenaire, S., Mohamed, N., Isaksson, M., Thorén, P., Klingeborn, B., Belák, S., et al. (2007). SYBR Green real-time reverse transcription-polymerase chain reaction assay for the generic detection of coronaviruses. Arch. Virol., 152, 41–58.
50. Fernando, A., Gonzalez, J. M., & Zoltan, P. (2000). Engineering the largest RNA virus genome as an infectious bacterial chromosome. Proc. Natl. Acad. Sci., 76, 5516–5521.
51. Fischer, F., Stegen, C. F., Koetzner, C. A., & Masters, P. S. (1997). Analysis of a recombinant mouse hepatitis virus expressing a foreign gene reveals a novel aspect of coronavirus transcription. J. Virol., 71, 5148–5160.
52. Flanagan, E. B., Zamparo, J. M., Ball, L. A., Rodriguez, L., & Wertz, G. W. (2001). Rearrangement of the genes of vesicular stomatitis virus eliminates clinical disease in the natural host: new strategy for vaccine development. J. Virol., 75, 6107– 6114.
53. Galan, A., Enjuanes, L., & Almazan, F. (2005). A point mutation within the replicase gene differentially affects coronavirus genome versus minigenome replication. J. Virol., 79, 15016–15026.
54. Gallagher, T., & Buchmeier, M. J. (2001). Coronavirus spike proteins in viral entry and pathogenesis. Virology, 279, 371–374.
55. Gebauer, F., Posthumus, W. A. P., Correa, I., Su, C., S nchez, C. M., Smerdou, C., et al. (1991).Residues involved in the antigenic sites of transmissible gastroenteritis coronavirus S glycoprotein. Virology, 183, 225–238.
56. Godet, M., Grosclaude, J., Delmas, B., & Laude, H. (1994). Major receptor-binding and neutralization determinants are located within the same domain of the transmissible gastroenteritis virus (coronavirus) spike protein. J. Virol., 68, 8008–8016.
57. Godet, M., Haridon, R. L., Vautherot, J. F., & Laude, H. (1992). TGEV ORF4 encodes a membrane protein that is incorporated into virus. J. Virol., 188, 666–675.
58. Gonz_lez, J. M., Penzes, Z., Almaz_n, F., Calvo, E., & Enjuanes, L. (2002). Stabilization of a fulllength infectious cDNA clone of transmissible gastroenteritis coronavirus by the insertion of an intron. J. Virol., 76, 4655–466.
59. Gorbalenya, A. E. (2001). Big nidovirus genome. When count and order of domains matter. Adv. Exp. Med. Biol., 494, 1–17.
60. Guan, Y., Zheng, B. J., He, Y. Q., Liu, X. L., Zhuang, Z. X., Cheung, C. L., et al. (2003). Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China. Science, 302, 276–278.
61. Haijema, B. J., Volders, H., & Rottier, P. J. (2004). Live, attenuated coronavirus vaccines through the directed deletion of group-specific genes provide protection against feline infectious peritonitis. J. Virol., 78, 3863?3871.
62. Haijema, B. J., Volders, H., & Rottier, P. J. M. (2003). Switching species tropism: an effective way to manipulate the feline coronavirus genome. J. Virol., 77, 4528–4538.
63. Halbur, P. G., Paul, P. S., Vaughn, E. M., & Andrews, J. J. (1993). Experimental reproduction of pneumonia in gnotobiotic pigs with porcine resplratory coronavirus isolate AR310. J. Vet. Diagn. Invest., 5, 184–188.
64. Hodgson, T., & Cavanagh, D. (2006). Neither the RNA nor the proteins of open reading frames 3a and 3b of the coronavirus infectious bronchitis virus are essential for replication. Virology, 80, 296–305.
65. Ivanov, K. A., Hertzig, T., Rozanov, M., Bayer, S., Thiel, V., Gorbalenya, A. E., et al. (2004). Major genetic marker of nidoviruses encodes a replicative endoribonuclease. Proc. Natl. Acad. Sci., 101, 12694–12699.
66. Izeta, A., Smerdou, C., Alonso, S., Penzes, Z., Mndez, A., Plana-Duran, J., et al. (1999). Replication and packaging of transmissible gastroenteritis coronavirusderived synthetic minigenomes. J. Virol., 73, 1535–1545.
67. Jia, W., Karaca, K., Parrish, C. R., & Naqi, S. A. (1995). A novel variant of avian infectious bronchitis virus resulting from recombination among three different strains. Arch. Virol., 140, 259–271.
68. Jung, K., & Chae, C. (2005). RT-PCR-based dot blot hybridization for the detection and differentiation between porcine epidemic diarrhea virus and transmissible gastroenteritis virus in fecal samples using a non-radioactive digoxigenin cDNA probe. J. Virol. Methods., 123, 141–146.
69. Jung, K., Kim, J., Kim, O., Kim, B., & Chae, C. (2003). Differentiation between porcine epidemic diarrhea virus and transmissible gastroenteritis virus in formalin-fixed paraffin-embedded tissues by multiplex RT-nested PCR and comparison with in situ hybridization. J. Virol. Methods., 108, 41–47.
70. Keck, J. G., Soe, L. H., Makino, S., Stohlman, S. A., & Lai, M. M. (1988). RNA recombination of murine coronaviruses: recombination between fusion-positive mouse hepatitis virus A59 and fusion-negative mouse hepatitis virus 2. J. Virol., 62, 1989–1998.
71. Kemeny, L. J., & Woods, R. D. (1977). Quantitative transmissible gastroenteritis virus shedding patterns in lactating sows. Am. J. Vet. Res., 38, 307–310.
72. Kim, B., & Chae, C. (2001). In situ hybridization for the detection of transmissible gastroenteritis virus in pigs and comparison with other methods. Can. J. Vet. Res., 65, 33–37.
73. Kim, L., Chang, K. O., Sestak, K., Parwani, A., & Saif, L. J. (2000). Development of a reverse transcription-nested polymerase chain reaction assay for differential diagnosis of transmissible gastroenteritis virus and porcine respiratory coronavirus from feces and nasal swabs of infected pigs. J. Vet. Diagn. Invest., 12, 385–388.
74. Kim, L., Hayes, J., Lewis, P., Parwani, A. V., Chang, K. O., & Saif, L. J. (2000). Molecular characterization and pathogenesis of transmissible gastroenteritis coronavirus (TGEV) and porcine respiratory coronavirus (PRCV) field isolates co-circulating in a swine herd. Arch. Virol., 145, 1133–1147.
75. Kim, O., Choi, C., Kim, B., & Chae, C. (2000). Detection and differentiation of porcine epidemic diarrhoea virus and transmissible gastroenteritis virus in clinical samples by multiplex RT-PCR. Vet. Rec., 146, 637–640.
76. Kim, S. H., Kim, I. J., Pyo, H. M., Tark, D. S., Song, J. Y., & Hyun, B. H. (2007). Multiplex real-time RT-PCR for the simultaneous detection and quantification of transmissible gastroenteritis virus and porcine epidemic diarrhea virus. J. Virol. Methods., 146, 172–177.
77. Kim, S. J., Han, J. H., & Kwon, H. M. (2003). Partial sequence of the spike glycoprotein gene of transmissible gastroenteritis viruses isolated in Korea. Vet. Microbiol., 94, 195–206.
78. Koetzner, C. A., Parker, M. M., Ricard, C. S., Sturman, L. S., & Masters, P. S. (1992). Repair and mutagenesis of the genome of a deletion mutant of the coronavirus mouse hepatitis virus by targeted RNA recombination. J. Virol., 66, 1841–1848.
79. Kozak, M. (1991). Structural features in eukaryotic mRNAs that modulate the initiation of translation. J. Biol. Chem., 266, 19867–19870.
80. Kristopher, M. C., Boyd, Y., & Ralph, S. B. (2002). Heterologous gene expression from transmissible gastroenteritis virus replicon particles. J. Virol., 76, 1422–1434.
81. Kubo, H., Yamada, Y. K., & Taguchi, F. (1994). Localization of neutralizing epitopes and the receptor-binding site within the amino-terminal 330 amino acids of the murine coronavirus spike protein. J. Virol., 68, 5403–5410.
82. Kuo, L., Godeke, G. J., Raamsman, M. J. B., Masters, P. S., & Rottier, P. J. M. (2000). Retargeting of coronavirus by substitution of the spike glycoprotein ectodomain: crossing the host cell species barrier. J. Virol., 74, 1393–1406.
83. Kwon, H. M., Saif, L. J., & Jackwood, D. J. (1998). Field isolates of transmissible gastroenteritis virus differ at the molecular level from the Miller and Purdue virulent and attenuated strains and from porcine respiratory coronaviruses. J. Vet. Med. Sci., 60, 589–597.
84. Lai, C. H., Welter, M. W., & Welter, L. M. (1995). The use of arms PCR and RFLP analysis in identifying genetic profiles of virulent, attenuated or vaccine strains of TGEV and PRCV. Adv. Exp. Med. Biol., 380, 243–250.
85. Lee, C., Park, C. K., Lyoo, Y. S., & Lee, D. S, (2008). Genetic differentiation of the nucleocapsid protein of Korean isolates of porcine epidemic diarrhoea virus by RT-PCR based restriction fragment length polymorphism analysis. J. Vet., 178, 138–140.
86. Lee, H. J., Shieh, C. K., Gorbalenya, A. E., Koonin, E. V., La Monica, N., Tuler, J., et al. (1991). The complete sequence (22 kilobases) of murine coronavirus gene 1 encoding the putative proteases and RNA polymerase. Virology, 180, 567–582.
87. Liu, S. W., Zhang, Q. X., Chen, J. F., Han, Z. X., Shao, Y. H., Kong, X. G., et al. (2008). Identification of the avian infectious bronchitis coronaviruses with mutations in gene 3. Gene, 412, 12–25.
88. Lomniczi, B. (1977). Biological properties of avian coronavirus RNA. J. Gen. Virol., 36, 531–533.
89. Lowings, P., Laudr, H., & Charley, B. (1997). Discrimination between transmissible gastroenteritis virus isolates. Arch. Virol., 142, 1703–1711.
90. Lu, W., Osorio, F. A., Rhodes, M. B., & Moxley, R. A. (1991). A capture-enzyme immunoassay for rapid diagnosis of transmissible gastroenteritis virus. J. Vet. Diagn. Invest., 3, 119–123.
91. Luo, Z., Matthews, A. M., & Weiss, S. R. (1999). Amino acid substitutions within the leucine zipper domain of the murine coronavirus spike protein cause defects in oligomerization and the ability to induce cell-to-cell fusion. J. Virol., 73, 8152–8159.
92. MacNamara, K. C., Chua, M. M., Nelson, P. T., Shen, H., & Weiss, S. R. (2005). Increased epitope-specific CD8+ T cells prevent murine coronavirus spread to the spinal cord and subsequent demyelination. J. Virol., 79, 3370–3381.
93. Makino, S., Keck, J. G., Stohlman, S. A., & Lai, M. M. (1986). High-frequency RNArecombination of murine coronaviruses. J. Virol., 57, 729–737.
94. Masters, P. S., & Rottier, P. J. (2005). Coronavirus reverse genetics by targeted RNA recombination. Curr. Top. Microbiol. Immunol., 287, 133–159.
95. Masters, P. S. (1999). Reverse genetics of the largest RNA viruses. Adv. Virus. Res., 53, 245–264.
96. Masters, P. S. (2006). The molecular biology of coronaviruses. Adv. Virus Res. 66, 193–292.
97. Matsuyama, S., & Taguchi, F. (2002). Receptor-induced conformational changes of murine coronavirus spike protein. J. Virol., 76, 11819–11826.
98. McGoldrick, A., Lowings , J. P., & Paton , D. J. (1999). Characterisation of a recent virulent transmissible gastroenteritis virus from Britain with a deleted ORF 3a. Arch. Virol., 144, 763–770.
99. McIntosh, K. (1974). Coronaviruses: a comparative review. Curr. Top. Microbiol. Immunol., 63, 85–129.
100. Mirmomeni, M. H., Hughes, P. J., & Stanway, G. (1997). An RNA tertiary structure in the 3' untranslated region of enteroviruses is necessary for efficient replication. J. Virol., 71, 2363–2370.
101. Navas, S., Seo, S. H., Chua, M. M., das Sarma, J., Lavi, E., Hingley, S. T., et al. (2001). Murine coronavirus spike protein determines the ability of the virus to replicate in the liver and cause hepatitis. J. Virol., 75, 2452–2457.
102. Nelsen, C. J., Murtaugh, M. P., & Faaberg, K. S. (1999). Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. J. Virol., 73, 270–280.
103. O_Connor, J. B., & Brian, D. A. (2000). Downstream ribosomal entry for translation of coronaviru TGEV gene 3b. Virology, 269, 172–182.
104. O’Connor, J. B., & Brian, D. A. (1999). The major product of porcine transmissible gastroenteritis virus coronavirus gene 3b is an integral membrane glycoprotein of 31kDa. J. Virol., 256, 152–161.
105. Ortego, J., De Diego, M. L., & Enjuanes, L. (2004). Novel human vector based on coronavirus genomes. Submitted for publication
106. Ortego, J., Sola, I., Almazan, F., Ceriani, J. E., Riquelme, C., Balasch, M., et al. (2003). Transmissible gastroenteritis coronavirus gene 7 is not essential but influences in vivo virus replication and virulence. Virology, 308, 13–22.
107. Ozdarendeli, A., Ku, S., Rochat, S., Senanayake, S. D., & Brian, D. A. (2001). Downstream sequences influence the choice between a naturally occurring noncanonical and closely positioned upstream canonical heptameric fusion motif during bovine coronavirus subgenomic mRNA synthesis. J. Virol., 75, 7362–7374.
108. Park, J. H., Han, J. H., & Kwon, H. M. (2008). Sequence analysis of the ORF 7 region of transmissible gastroenteritis viruses isolated in Korea. Virus Genes, 36, 71–78.
109. Pasternak, A. O., van den Born, E,, Spaan, W. J. M., & Snijder, E. J. (2001). Sequence requirements for RNA strand transfer during nidovirus discontinuous subgenomic RNA synthesis.EMBO. J., 20, 7220–7228.
110. Pasternak, A. O., van den Born, E., Spaan, W. J. M., & Snijder, E. J. (2003). The stability of the duplex between sense and antisense transcription-regulating sequences is a crucial factor in arterivirus subgenomic mRNA synthesis. J. Virol., 77, 1175–1183.
111. Paton, D., & Lowings, P. (1997). Discrimination between transmissible gastroenteritis virus isolates. Arch. Virol., 142, 1703–1711.
112. Paton, D., Ibata, G., Sands, J., & McGoldrick, A. (1997). Detection of transmissible gastroenteritis virus by RT-PCR and differentiation from porcine respiratory coronavirus. J. Virol. Methods., 66, 303–309.
113. Pensaert, M., Callebaut, P., & Vergote, J. (1986). Isolation of a porcine respiratory, non-enteric coronavirus related to transmissible gastroenteritis. Vet. Q., 8, 257–261.
114. Penzes, Z., Gonz_lez, J. M., Calvo, E., Izeta, A., Smerdou, C., Mendez, A., et al. (2001). Complete genome sequence of transmissible gastroenteritis coronavirus PUR46-MAD clone and evolution of the Purdue virus cluster. Virus Genes, 23, 105–118.
115. Phillips, J. J., Chua, M. M., Lavi, E., & Weiss, S. R. (1999). Pathogenesis of chimeric MHV4/ MHV-A59 recombinant viruses: the murine coronavirus spike protein is a major determinant of neurovirulence. J. Virol., 73, 7752–7760.
116. Prentice, E., McAuliffe, J., Lu, X., Subbarao, K., & Denison, M. R. (2004). Identification and characterization of severe acute respiratory syndrome coronavirus replicase proteins. J. Virol., 78, 9977–9986.
117. Pritchard, G. C. (1987). Transmissible gastroenteritis in endemically infected breeding herds of pigs in East Anglia. 1981-85. Vet. Rec ., 120, 226–230.
118. Racaniello, V. R., & Baltimore, D. (1995). Cloned polivirus comlementary DNA is infectious in mammalian(S.G. Siddell, ed.). Plenum Press New York and London. pp. 191–2171.
119. Register, K. B., & Wesley, R. D. (1994). Molecular characterization of attenuated vaccine strains of transmissible gastroenteritis virus. J. Vet. Diagn. Invest., 6, 16–22.
120. Riffault, S., Grosclaude, J., Vayssier, M., Laude, H., & Charley, B. (1997). Reconstitued coronavirus TGEV virosomes lose the virus ability to induce porcine interferon alpha production. Vet. Res., 28, 105–114.
121. Rodák, L., Smíd, B., Nevoránková, Z., Valícek, L., & Smítalová, R. (2005). Use of Monoclonal Antibodies in Blocking ELISA Detection of Transmissible Gastroenteritis Virus in Faeces of Piglets. J. Vet. Med. B. Infect. Dis. Vet. Public. Health., 52, 105–111.
122. Aliper, T. I., Rukhadze, G. G., Sergeev, V. A., & Shcheglova, E. (1988). Development of test systems for immunoenzyme analysis for the detection of the antigen of the transmissible gastroenteritis virus of swine. Vopr. Virusol., 33, 315–319.
123. S_nchez, C. M., Gebauer, F., Su, C., Mndez, A., Dopazo, J., & Enjuanes, L. (1992). Genetic evolution and tropism of transmissible gastroenteritis coronaviruses. Virology, 190, 92– 105.
124. S_nchez, C. M., Izeta, A., S_nchez-Morgado, J. M., Alonso, S., Sola, I., Balasch, M., et al. (1999). Targeted recombination demonstrates that the spike gene of transmissible gastroenteritis coronavirus is a determinant of its enteric tropism and virulence. J. Virol., 73, 7607–7618.
125. Saif, L. J., & Sestak, K. (2006). Transmissible gastroenteritis virus and porcine respiratory coronavirus. In Straw BE, Zimmerman JJ, D’Allaire S, Taylor DJ (Eds.): Diseases of Swine. 9th ed. Blackwell Publishing. Iowa. pp. 489–516.
126. Saif, L. J. (2004). Animal coronaviruses: what can they teach us about the severe acute respiratory syndrome? Rev. Sci. Technol., 23, 643–660.
127. Sanchez, C. M., Gebauer, F., Sune, C., Mendez, A., Dopazo, J., & Enjuanes, L. (1992). Genetic evolution and tropism of transmissible gastroenteritis coronaviruses. Virology, 190, 92–105.
128. Sanchez, C. M., Izeta, A., Sanchez-Morgado, J. M., Alonso, S., Sola, I., Balasch. M., et al. (1999). Targeted Recombination Demonstrates that the Spike Gene of Transmissible Gastroenteritis Coronavirus Is a Determinant of Its Enteric Tropism and Virulence. J. Virol., 73, 7607–7618.
129. Sanchez, C. M., Sola, I., Sanchez-Morgado, J. M., & Enjuanes, L. (2004). The amino terminus of transmissible gastroenteritis coronavirus spike protein dictates the enteric tropism of the virus. J. Virol., 73, 7607–7618.
130. Sarma, D. J., Scheen, E., Seo, S. H., Koval, M., & Weiss, S. R. (2002). Enhanced green fluorescent protein expression may be used to monitor murine coronavirus spread in vitro and in the mouse central nervous system. J. Neurovirol., 8, 381–391.
131. Shen, S., Wen, Z. L., & Liu, D. X. (2003). Emergence of a coronavirus infectious bronchitis virus mutant with a truncated 3b gene: functional characterization of the 3b protein in pathogenesis and replication. Virology, 311, 16–27.
132. Shockley, L. J., Kapke, P. A., Lapps, W., Brian, D. A., Potgieter, L. N., & Woods, R. (1987). Diagnosis of porcine and bovine enteric coronaviruses infections using cloned cDNA probe. J Clin. Microbiol., 25, 1591–1596.
133. Sirinarumitr, T., Paul, P. S., Kluge, J. P., & Halbur, P. G. (1996). In situ hybridization technique for the detection of swine enteric and respiratory coronaviruses transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV), in formalin-fixed paraffin-embedded tissues. J. Vir. Met., 56, 146–160.
134. Snijder, E. J., Bredenbeek, P. J., Dobbe, J. C., Thiel, V., Ziebuhr, J., Poon, L. L., Guan, Y., et al. (2003). Unique and conserved features of genome and proteome of SARS-coronavirus, an early split-off from the coronavirus group 2 lineage. J. Mol. Biol., 331, 991–1004.
135. Sola, I., Alonso, S., Zuniga, S., Balasch, M., Plana-Duran, J., & Enjuanes, L. (2003). Engineeringthe Transmissible Gastroenteritis Virus Genome as an Expression Vector Inducing Lactogenic Immunity. J. Virol., 77, 4357–4369.
136. Sola, L., Alonso, S., & Sanchez, C. (2001). Expression of transcriptional units using transmissible gastroenteritis coronavirus derived minigenomes and full–length cDNA clones. Adv. Exp. Med. Biol., 494, 447–451.
137. Song, D. S., Kang, B. K., Oh, J. S., Ha, G. W., Yang, J. S., Moon, H. J., et al. (2006). Multiplex reverse transcription-PCR for rapid differential detection of porcine epidemic diarrhea virus, transmissible gastroenteritis virus, and porcine group a rotavirus. J. Vet. Diagn. Invest., 18, 278–281.
138. Song, D. S., Yang, J. S., Oh, J. S., Han, J. H., & Park, B. K. (2003). Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF3. Vaccine, 21, 1833–1842.
139. Sperry, S., Kazi, L., Graham, R., Baric, R., Weiss, S., & Denison, M. (2005). Single amino acid substitutions in nonstructural ORF1b-nsp14 and ORF2a 30kDa proteins of the murine coronavirus MHV-A59 are attenuating in mice. J. Virol., 79, 3391–3400.
140. Taguchi, F., Kubo, H., Takahashi, H., & Suzuki, H. (1995). Localization of neurovirulence determinant for rats on the S1 subunit of murine coronavirus JHMV. Virology, 208, 67–74.
141. Taniguchi, T., Palmieri, M., & Weissmann, C. (1978). QB DNA-containing hybrid plasmids giving rise to QB phage formation in the bacterial host. Nature, 274, 223–228.
142. Thiel, V., Herold, J., Schelle, B., & Siddell, S. G. (2001). Infectious RNA transcribed in vitro from a cDNA copy of the human coronavirus genome cloned in vaccinia virus. J. Gen. Virol., 82, 1273–1281.
143. Thiel, V., Ivanov, K. A., Putics,á., Hertzig, T., Schelle, B., Bayer, S., et al. (2003). Mechanisms and enzymes involved in SARS coronavirus genome expression. J. Gen. Virol., 84, 2305–2315.
144. Tyrrell, D. A., Almeida, J. D., Cunningham, C. H., Hofstad, M. S., Hampre, D., Mallucci, L., et al. (1968). Coronavirus. Nature, 220, 650.
145. van Marle. G., Dobbe, J. C., Gultyaev, A. P., Luytjes, W., Spaan, W. J. M., & Snijder, E. J. (1999). Arterivirus discontinuous mRNA transcription is guided by base pairing between sense and antisense transcription-regulating sequences. Proc. Natl. Acad. Sci., 96, 12056–12061.
146. Vaughn, R. M., Halbur, P. G., & Paul, P. S. (1995). Sequence comparison of porcine respiratory coronaviruses isolates reveals heterogeneity in the S, 3, and 3-1 genes. J. Virol., 69, 3176–3184.
147. Vijgen, L., Keyaerts, E., Moes, E., Thoelen, I., Wollants, F., & Lemey, P. (2005). Complete genomic sequence of human coronavirus OC43: molecular clock analysis suggests a relatively recent zoonotic coronavirus transmission event. J. Virol., 79, 1595–1604.
148. Wang, L., Junker, D., & Collisson, E. W. (1993). Evidence of natural recombination within the S1gene of infectious bronchitis virus. Virology, 192, 710–716.
149. Wertz, G. W., Perepelitsa, V. P., & Ball, L. A. (1998). Gene rearrangement attenuates expression and lethality of a nonsegmented negative strand RNA virus. Proc. Natl. Acad. Sci., 95, 3501–3506.
150. Wesley, R., Woods, R., & Cheuny, A. (1990). Genetic basis of the pathogenesis of transmissible gastroenteritis virus. J. Viro1., 64, 4761–476.
151. Wesley, R. D., Cheung, A. K., Michael, D. M., & Woods, R. D. (1989). Nucleotide sequence of coronavirus TGEV genomic RNA: evidence of 3 mRNA species between the peplomer and matrix protein genes. Virus. Res., 13, 87–100.
152. Wesley, R. D., Woods, R. D., & Cheung, A. K. (1991). Genetic analysis of porcine respiratory coronavirus, an attenuated variant of transmissible gastroenteritis virus. J. Virol., 65, 3369–3373.
153. Wesley, R. D., Woods, R. D., Hill, H. T., & Biwer, J. D. (1990). Evidence for a porcine respiratory coronavirus, antigenically similar to transmissible gastroenteritis virus, in the United States. J. Vet. Diagn. Invest., 2, 312–317.
154. Wood, E. N., Pritchard, G. C., & Gibson, E. A. (1981). Transmissible gastroenteritis of pigs. Vet. Rec., 108, 41.
155. Wood, R. D. (2001). Efficiency of a transmissible gastroenteritis coronavirus with an altered ORF3 gene .Can. J. Vet. Res., 65, 28–32.
156. Woods, R. D., & Wesley, R. D. (1986). Immune response in sows given transmissible gastroenteritis virus or canine coronavirus. Am. J. Vet. Res., 47, 1239–1242.
157. Woods, R. D. (1976). Leukocyte-aggregation assay for transmissible gastroenteritis of swine. Am. J. Vet. Res., 37, 1405–1408.
158. Woods, R. D. (1997). Development of PCR-based techniques to identify porcine transmissible gastroenteritis coronavirus isolates. Can. J. Vet. Res., 61, 167–172.
159. Woods, R. D. (2001.) Efficacy of a transmissible gastroenteritis coronavirus with an altered ORF-3 gene. Can. J. Vet. Res., 65, 28–32.
160. Wuru, T., Chen, H., Hoddgson, T., Britton, P., Brooks, G. A., & Hiscox, J. (2001). Localization to the nucleolus is a common feature of coronavirus nucleoproteins and the protein may disrupt host cell division. J. Virol., 75, 9345–9356.
161. Yeager, C. L., Ashmun, R. A., Williams, R. K., Cardellichio, C. B., Shapiro, L. H., Look, A. T., et al. (1992). Human aminopeptidase N is a receptor for human coronavirus 229E. Nature, 357, 420–422.
162. Yin, J. C., Ren, X. F., & Li, Y. J. (2005). Molecular cloning and phylogenetic analysis of ORF7 region of Chinese isolate TH-98 from transmissible gastroenteritis virus. Virus Genes, 30, 395–401.
163. Youn, S., Leibowitz, J. L., & Collisson, E. W. (2005). In vitro assembled, recombinant infectiousbronchitis viruses demonstrate that the 5a open reading frame is not essential for replication. Virology, 332, 206–215.
164. Yount, B., Curtis, K. M., & Baric, R. S. (2000). Strategy for systematic assembly of large RNA and DNA genomes: transmissible gastroenteritis virus model. J. Virol., 74, 10600–10611.
165. Yount, B., Curtis, K. M., Fritz, E. A., Hensley, L. E., Jahrling, P. B., Prentice, E., et al. (2003). Reverse genetics with a full–length infectious cDNA of severe acute respiratory syndrome coronavirus. Proc. Natl. Acad. Sci., 100, 12995–13000.
166. Yount, B., Denison, M. R., Weiss, S. R., & Baric, R. S. (2002). Systematic assembly of a full-length infectious cDNA of mouse hepatitis virus strain A59. J. Virol., 76, 11065–11078.
167. Zelus, B. D., Schickli, J. H., Blau, D. M., Weiss, S. R., & Holmes, K. V. (2003). The N-terminal domain of the murine coronavirus spike glycoprotein determines the CEACAM1 receptor specificity of the virus strain. J. Virol., 77, 830–840.
168. Zhang, X. M., & Liu, R. Z. (2000). Identification of a noncanonical signal for transcription of a novel subgenomic mRNA of mouse hepatitis virus: implication for the mechanism of coronavirus RNA transcription. Virology, 278, 75–85.
169. Zhang, X. S., Hasoksuz, M., Spiro, D., Halpin, R., Wang, S. L., Stollar, S., et al. (2007). Complete genomic sequences, a key residue in the spike protein and deletions in non-structural protein 3b of US strains of the virulent and attenuated coronaviruses, transmissible gastroenteritis virus and porcine respiratory coronavirus. Virology, 358, 424–435.
170. Ziebuhr, J. (2005). The coronavirus replicase. Curr. Top. Microbiol. Immunol. 287, 57–94.
171. Ziebuhr, J., Thiel, V., & Gorbalenya, A. E. (2001). The autocatalytic release of a putative RNA virus transcription factor from its polyprotein precursor involves two paralogous papain-like proteases that cleave the same peptide bond. J. Biol. Chem., 276, 33220–33232.