小鼠新印记基因Peg14的分离鉴定及表达分析
|
摘要
印记基因是基因组中一小部分亲本来源特异性沉默的基因。目前,已经在小鼠中鉴定出的印记基因数量超过100个,其中多数基因是母本表达,少数为父本表达。2009年Kobayashi等利用孤雌生殖胚胎鉴定出第一个小鼠1号染色体上的父本表达印记基因Zdbf2,本课题根据印记基因通常成簇分布于染色体上这一特点,在Zdbf2基因邻近区域检索侯选印记的EST,并对其中的EST——CJ051953进行了分离、印记鉴定及表达分析。
在印记鉴定中,以C57BL/6J与ICR的杂交品系作为实验材料,采用基于SNP标记的RT-PCR直接测序法,直接分析了双亲等位基因的表达情况。印记分析结果表明CJ051953为父本优先表达的印记基因,其印记具有组织及发育阶段特异性,命名为Peg14 (paternal expression gene 14)。全胚胎原位杂交结果表明,较强的Peg14信号出现在小鼠E9.5天的菱脑、面部间充质、神经管及E11.5天的端脑、中脑和菱脑等组织。E12.5天组织切片原位杂交的结果显示,该基因在前脑、中脑、后脑和垂体中的信号较强,在脊髓及体节中相对较弱。此外,我们进一步利用全胚胎半定量RT-PCR法对该基因在胚胎发育中后期的表达情况进行了分析,结果显示,Peg14基因在发育的中后期持续性表达,其中,E9.5天表达水平最低,E11.5天表达量达到最高值。
这种在脑部集中的表达模式,以及在脑中的印记状态表明,Peg14基因可能在小鼠胚胎神经系统的发育中发挥重要作用。
Imprinted genes are a small proportion of genes on the genome showing parent-of-origin-specific silencing. Up to now, more than 100 imprinted genes have been identified in mouse. Most of them are expressed from the maternal allele and the others from the paternal allele. The first paternally expressed imprinted gene Zdbf2 on mouse chromosome 1 was identified by Kobayashi et al using parthenogenetic embryos in 2009. In our research, EST of candidate imprinted genes was searched in the area closed to Zdbf2 according to the characteristic feature that imprinted genes are generally physically linked in clusters with other ones on chromosomes, and the isolation, identification and expression analysis of the EST——CJ051953 were investigated.
Strain cross of C57BL/6J and ICR was used as experimental material to achieve imprinting identification. Expression of parental alleles were analysed using direct sequencing of RT-PCR based on SNP. The result showed that CJ051953 which named Peg14 (paternal expression gene 14) was biased in favor of the paternal allele and presented tissue-specific and developmental stage-specific expression profiles. Whole-mount in situ hybridization showed that strong signal of Peg14 appeared in the rhombencephalon, facial mesenchyme, neural tube at E9.5 and telencephalon, midbrain, rhombencephalon at E11.5. The result of in situ hybridization at E12.5 showed that the signal of Peg14 was relatively strong in the forebrain, midbrain,hindbrain and pituitary gland, while weaker in the spinal cord and somite. In addition, expression analysis was carried out by whole embryo semi-quantitative RT-PCR. The result showed that Peg14 expressed continuously in middle-late developmental stage. Peg14 exhibited the lowest expression level at E9.5 and reached the highest expression level at E11.5.
This expression profile concentrated and imprinted in the brain indicate that Peg14 may have an important effect on the development of the nervous system of the mouse embryo.
在印记鉴定中,以C57BL/6J与ICR的杂交品系作为实验材料,采用基于SNP标记的RT-PCR直接测序法,直接分析了双亲等位基因的表达情况。印记分析结果表明CJ051953为父本优先表达的印记基因,其印记具有组织及发育阶段特异性,命名为Peg14 (paternal expression gene 14)。全胚胎原位杂交结果表明,较强的Peg14信号出现在小鼠E9.5天的菱脑、面部间充质、神经管及E11.5天的端脑、中脑和菱脑等组织。E12.5天组织切片原位杂交的结果显示,该基因在前脑、中脑、后脑和垂体中的信号较强,在脊髓及体节中相对较弱。此外,我们进一步利用全胚胎半定量RT-PCR法对该基因在胚胎发育中后期的表达情况进行了分析,结果显示,Peg14基因在发育的中后期持续性表达,其中,E9.5天表达水平最低,E11.5天表达量达到最高值。
这种在脑部集中的表达模式,以及在脑中的印记状态表明,Peg14基因可能在小鼠胚胎神经系统的发育中发挥重要作用。
Imprinted genes are a small proportion of genes on the genome showing parent-of-origin-specific silencing. Up to now, more than 100 imprinted genes have been identified in mouse. Most of them are expressed from the maternal allele and the others from the paternal allele. The first paternally expressed imprinted gene Zdbf2 on mouse chromosome 1 was identified by Kobayashi et al using parthenogenetic embryos in 2009. In our research, EST of candidate imprinted genes was searched in the area closed to Zdbf2 according to the characteristic feature that imprinted genes are generally physically linked in clusters with other ones on chromosomes, and the isolation, identification and expression analysis of the EST——CJ051953 were investigated.
Strain cross of C57BL/6J and ICR was used as experimental material to achieve imprinting identification. Expression of parental alleles were analysed using direct sequencing of RT-PCR based on SNP. The result showed that CJ051953 which named Peg14 (paternal expression gene 14) was biased in favor of the paternal allele and presented tissue-specific and developmental stage-specific expression profiles. Whole-mount in situ hybridization showed that strong signal of Peg14 appeared in the rhombencephalon, facial mesenchyme, neural tube at E9.5 and telencephalon, midbrain, rhombencephalon at E11.5. The result of in situ hybridization at E12.5 showed that the signal of Peg14 was relatively strong in the forebrain, midbrain,hindbrain and pituitary gland, while weaker in the spinal cord and somite. In addition, expression analysis was carried out by whole embryo semi-quantitative RT-PCR. The result showed that Peg14 expressed continuously in middle-late developmental stage. Peg14 exhibited the lowest expression level at E9.5 and reached the highest expression level at E11.5.
This expression profile concentrated and imprinted in the brain indicate that Peg14 may have an important effect on the development of the nervous system of the mouse embryo.
引文
[1] Crouse H V. The Controlling Element in Sex Chromosome Behavior in Sciara[J]. Genetics. 1960, 45(10): 1429-43.
[2] Willison K. Opposite Imprinting of the Mouse Igf2 and Igf2r Genes[J]. Trends in Genetics. 1991, 7(4): 107-109.
[3] Luedi P P, Hartemink A J, Jirtle R L. Genome-Wide Prediction of Imprinted Murine Genes[J]. Genome Research. 2005, 15(6): 875-884.
[4] Kobayashi H, Yamada K, Morita S, et al. Identification of the Mouse Paternally Expressed Imprinted Gene Zdbf2 on Chromosome 1 and Its Imprinted Human Homolog ZDBF2 on Chromosome 2[J]. Genomics. 2009, 93(5): 461-472.
[5] Hiura H, Sugawara A, Ogawa H, et al. A Tripartite Paternally Methylated Region within the Gpr1-Zdbf2 Imprinted Domain on Mouse Chromosome 1 Identified by Medip-on-Chip[J]. Nucleic Acids Research. 2010, 38(15): 4929-4945.
[6] Morison I M, Ramsay J P, Spencer H G. A Census of Mammalian Imprinting[J]. Trends in Genetics. 2005, 21(8): 457-65.
[7] Miyoshi N, Wagatsuma H, Wakana S, et al. Identification of an Imprinted Gene, Meg3/Gtl2 and Its Human Homologue MEG3, First Mapped on Mouse Distal Chromosome 12 and Human Chromosome 14q[J]. Genes to Cells. 2000, 5(3): 211-220.
[8] Kuzmin A, Han Z M, Golding M C, et al. The Pcg Gene Sfmbt2 Is Paternally Expressed in Extraembryonic Tissues[J]. Gene Expression Patterns. 2008, 8(2): 107-116.
[9] Yang T, Adamson T E, Resnick J L, et al. A Mouse Model for Prader-Willi Syndrome Imprinting-Centre Mutations[J]. Nat Genet. 1998, 19(1): 25-31.
[10] Reik W, Walter J. Genomic Imprinting: Parental Influence on the Genome[J]. Nat Rev Genet. 2001, 2(1): 21-32.
[11] Reed M L, Leff S E. Maternal Imprinting of Human SNRPN, a Gene Deleted in Prader-Willi Syndrome[J]. Nature Genetics. 1994, 6(2): 163-7.
[12] Jay P, Rougeulle C, Massacrier A, et al. The Human Necdin Gene, NDN, Is Maternally Imprinted and Located in the Prader-Willi Syndrome Chromosomal Region[J]. Nature Genetics. 1997, 17(3): 357-61.
[13] Lee S, Kozlov S, Hernandez L, et al. Expression and Imprinting of Magel2 Suggest a Role in Prader-Willi Syndrome and the Homologous Murine Imprinting Phenotype[J]. Hum Mol Genet. 2000, 9(12): 1813-9.
[14] Wevrick R, Francke U. An Imprinted Mouse Transcript Homologous to the Human Imprinted in Prader-Willi Syndrome (Ipw) Gene[J]. Hum Mol Genet. 1997, 6(2): 325-32.
[15] Rougeulle C, Cardoso C, Fontes M, et al. An Imprinted Antisense RNA Overlaps Ube3a and a Second Maternally Expressed Transcript[J]. Nature Genetics. 1998, 19(1): 15-6.
[16] Herzing L B, Kim S J, Cook E H, Jr., et al. The Human Aminophospholipid-Transporting ATPase Gene ATP10C Maps Adjacent to UBE3A and Exhibits Similar Imprinted Expression[J]. Am J Hum Genet. 2001, 68(6): 1501-5.
[17] Reik W, Walter J. Genomic Imprinting: Parental Influence on the Genome[J]. Nature Reviews Genetics. 2001, 2(1): 21-32.
[18] Yang T, Adamson T E, Resnick J L, et al. A Mouse Model for Prader-Willi Syndrome Imprinting-Centre Mutations[J]. Nature Genetics. 1998, 19(1): 25-31.
[19] Neumann B, Kubicka P, Barlow D P. Characteristics of Imprinted Genes, (Vol 9, Pg 12, 1995)[J]. Nature Genetics. 1995, 9(4): 451-451.
[20] Guillemot F, Caspary T, Tilghman S M, et al. Genomic Imprinting of Mash2, a Mouse Gene Required for Trophoblast Development[J]. Nature Genetics. 1995, 9(3): 235-42.
[21] Lee J T, Jaenisch R. The (Epi)Genetic Control of Mammalian X-Chromosome Inactivation[J]. Curr Opin Genet Dev. 1997, 7(2): 274-80.
[22] Hikichi T, Kohda T, Kaneko-Ishino T, et al. Imprinting Regulation of the Murine Meg1/Grb10 and Human Grb10 Genes; Roles of Brain-Specific Promoters and Mouse-Specific Ctcf-Binding Sites[J]. Nucleic Acids Research. 2003, 31(5): 1398-406.
[23] Reinhart B, Eljanne M, Chaillet J R. Shared Role for Differentially Methylated Domains of Imprinted Genes[J]. Mol Cell Biol. 2002, 22(7): 2089-98.
[24] Ferguson-Smith A C, Sasaki H, Cattanach B M, et al. Parental-Origin-Specific Epigenetic Modification of the Mouse H19 Gene[J]. Nature. 1993, 362(6422): 751-5.
[25] Kitsberg D, Selig S, Brandeis M, et al. Allele-Specific Replication Timing of Imprinted Gene Regions[J]. Nature. 1993, 364(6436): 459-63.
[26] Sleutels F, Zwart R, Barlow D P. The Non-Coding Air RNA Is Required for Silencing Autosomal Imprinted Genes[J]. Nature. 2002, 415(6873): 810-813.
[27] Yoon B, Herman H, Hu B, et al. Rasgrf1 Imprinting Is Regulated by a Ctcf-Dependent Methylation-Sensitive Enhancer Blocker[J]. Molecular and Cellular Biology. 2005, 25(24): 11184-11190.
[28] Santos-Rosa H, Caldas C. Chromatin Modifier Enzymes, the Histone Code and Cancer[J]. Eur J Cancer. 2005, 41(16): 2381-402.
[29] Kouzarides T. Chromatin Modifications and Their Function[J]. Cell. 2007, 128(4): 693-705.
[30] Kim J K, Samaranayake M, Pradhan S. Epigenetic Mechanisms in Mammals[J].Cell Mol Life Sci. 2009, 66(4): 596-612.
[31] Pauler F M, Koerner M V, Barlow D P. Silencing by Imprinted Noncoding Rnas: Is Transcription the Answer?[J]. Trends in Genetics. 2007, 23(6): 284-292.
[32] Shastry B S. SNP Alleles in Human Disease and Evolution[J]. J Hum Genet. 2002, 47(11): 561-6.
[33] Khatib H. Imprinting of Nesp55 Gene in Cattle[J]. Mammalian Genome. 2004, 15(8): 663-7.
[34] Ono R, Shiura H, Aburatani H, et al. Identification of a Large Novel Imprinted Gene Cluster on Mouse Proximal Chromosome 6[J]. Genome Research. 2003, 13(7): 1696-705.
[35] Evans H K, Wylie A A, Murphy S K, et al. The Neuronatin Gene Resides in a "Micro-Imprinted" Domain on Human Chromosome 20q11.2[J]. Genomics. 2001, 77(1-2): 99-104.
[36] Kaneko-Ishino T, Kuroiwa Y, Miyoshi N, et al. Peg1/Mest Imprinted Gene on Chromosome 6 Identified by Cdna Subtraction Hybridization[J]. Nature Genetics. 1995, 11(1): 52-9.
[37] Kuroiwa Y, Kaneko-Ishino T, Kagitani F, et al. Peg3 Imprinted Gene on Proximal Chromosome 7 Encodes for a Zinc Finger Protein[J]. Nature Genetics. 1996, 12(2): 186-90.
[38] Kagitani F, Kuroiwa Y, Wakana S, et al. Peg5/Neuronatin Is an Imprinted Gene Located on Sub-Distal Chromosome 2 in the Mouse[J]. Nucleic Acids Research. 1997, 25(17): 3428.
[39] Miyoshi N, Kuroiwa Y, Kohda T, et al. Identification of the Meg1/Grb10 Imprinted Gene on Mouse Proximal Chromosome 11, a Candidate for the Silver-Russell Syndrome Gene[J]. Proc Natl Acad Sci U S A. 1998, 95(3): 1102-7.
[40] Piras G, El Kharroubi A, Kozlov S, et al. Zac1 (Lot1), a Potential Tumor Suppressor Gene, and the Gene for Varepsilon-Sarcoglycan Are Maternally Imprinted Genes: Identification by a Subtractive Screen of Novel Uniparental Fibroblast Lines[J]. Molecular and Cellular Biology. 2000, 20(9): 3308.
[41] Jayapal M, Melendez A J. DNA Microarray Technology for Target Identification and Validation[J]. Clin Exp Pharmacol Physiol. 2006, 33(5-6): 496-503.
[42] Yan P S, Chen C M, Shi H, et al. Dissecting Complex Epigenetic Alterations in Breast Cancer Using Cpg Island Microarrays[J]. Cancer Research. 2001, 61(23): 8375.
[43] Kobayashi S, Wagatsuma H, Ono R, et al. Mouse Peg9/Dlk1 and Human PEG9/DLK1 Are Paternally Expressed Imprinted Genes Closely Located to the Maternally Expressed Imprinted Genes: Mouse Meg3/Gtl2 and Human MEG3[J]. Genes to Cells. 2000, 5(12): 1029-37.
[44] Mizuno Y, Sotomaru Y, Katsuzawa Y, et al. Asb4, Ata3, and Dcn Are NovelImprinted Genes Identified by High-Throughput Screening Using Riken Cdna Microarray[J]. Biochem Biophys Res Commun. 2002, 290(5): 1499-505.
[45] Schulz R, Menheniott T R, Woodfine K, et al. Chromosome-Wide Identification of Novel Imprinted Genes Using Microarrays and Uniparental Disomies[J]. Nucleic Acids Research. 2006, 34(12): e88.
[46] Hagiwara Y, Hirai M, Nishiyama K, et al. Screening for Imprinted Genes by Allelic Message Display: Identification of a Paternally Expressed Gene Impact on Mouse Chromosome 18[J]. Proc Natl Acad Sci U S A. 1997, 94(17): 9249-54.
[47]张凤伟.猪七个候选印记基因的分离、印记鉴定及其与性状的关联分析[J].华中农业大学学位论文. 2007.
[48] Hatada I, Hayashizaki Y, Hirotsune S, et al. A Genomic Scanning Method for Higher Organisms Using Restriction Sites as Landmarks[J]. Proc Natl Acad Sci U S A. 1991, 88(21): 9523-7.
[49] Kawai J, Hirotsune S, Hirose K, et al. Methylation Profiles of Genomic DNA of Mouse Developmental Brain Detected by Restriction Landmark Genomic Scanning (Rlgs) Method[J]. Nucleic Acids Research. 1993, 21(24): 5604-8.
[50] Hayashizaki Y, Shibata H, Hirotsune S, et al. Identification of an Imprinted U2af Binding Protein Related Sequence on Mouse Chromosome 11 Using the Rlgs Method[J]. Nature Genetics. 1994, 6(1): 33-40.
[51] Plass C, Shibata H, Kalcheva I, et al. Identification of Grf1 on Mouse Chromosome 9 as an Imprinted Gene by Rlgs-M[J]. Nat Genet. 1996, 14(1): 106-9.
[52] Smith R J, Dean W, Konfortova G, et al. Identification of Novel Imprinted Genes in a Genome-Wide Screen for Maternal Methylation[J]. Genome Research. 2003, 13(4): 558-69.
[53] Gall J G, Pardue M L. Formation and Detection of RNA-DNA Hybrid Molecules in Cytological Preparations[J]. Proc Natl Acad Sci U S A. 1969, 63(2): 378-83.
[54] Buongiorno-Nardelli M, Amaldi F. Autoradiographic Detection of Molecular Hybrids between RNA and DNA in Tissue Sections[J]. Nature. 1970, 225(5236): 946-8.
[55] Orth G, Jeanteur P, Croissant O. Evidence for and Localization of Vegetative Viral DNA Replication by Autoradiographic Detection of RNA-DNA Hybrids in Sections of Tumors Induced by Shope Papilloma Virus[J]. Proceedings of the National Academy of Sciences. 1971, 68(8): 1876.
[56] Bauman J, Wiegant J, Borst P, et al. A New Method for Fluorescence Microscopical Localization of Specific DNA Sequences by in Situ Hybridization of Fluorochrome-Labelled RNA[J]. Experimental Cell Research. 1980, 128(2): 485-490.
[57] Langer-Safer P R, Levine M, Ward D C. Immunological Method for MappingGenes on Drosophila Polytene Chromosomes[J]. Proceedings of the National Academy of Sciences. 1982, 79(14): 4381.
[58] Ohlsson R, Hedborg F, Holmgren L, et al. Overlapping Patterns of Igf2 and H19 Expression During Human Development: Biallelic Igf2 Expression Correlates with a Lack of H19 Expression[J]. Development. 1994, 120(2): 361.
[59] Li T, Vu T H, Zeng Z L, et al. Tissue-Specific Expression of Antisense and Sense Transcripts at the Imprinted Gnas Locus* 1[J]. Genomics. 2000, 69(3): 295-304.
[60] Jiang S, Hemann M A, Lee M P, et al. Strain-Dependent Developmental Relaxation of Imprinting of an Endogenous Mouse Gene, Kvlqt1[J]. Genomics. 1998, 53(3): 395-399.
[61] Yevtodiyenko A, Carr M S, Patel N, et al. Analysis of Candidate Imprinted Genes Linked to Dlk1-Gtl2 Using a Congenic Mouse Line[J]. Mammalian Genome. 2002, 13(11): 633-8.
[2] Willison K. Opposite Imprinting of the Mouse Igf2 and Igf2r Genes[J]. Trends in Genetics. 1991, 7(4): 107-109.
[3] Luedi P P, Hartemink A J, Jirtle R L. Genome-Wide Prediction of Imprinted Murine Genes[J]. Genome Research. 2005, 15(6): 875-884.
[4] Kobayashi H, Yamada K, Morita S, et al. Identification of the Mouse Paternally Expressed Imprinted Gene Zdbf2 on Chromosome 1 and Its Imprinted Human Homolog ZDBF2 on Chromosome 2[J]. Genomics. 2009, 93(5): 461-472.
[5] Hiura H, Sugawara A, Ogawa H, et al. A Tripartite Paternally Methylated Region within the Gpr1-Zdbf2 Imprinted Domain on Mouse Chromosome 1 Identified by Medip-on-Chip[J]. Nucleic Acids Research. 2010, 38(15): 4929-4945.
[6] Morison I M, Ramsay J P, Spencer H G. A Census of Mammalian Imprinting[J]. Trends in Genetics. 2005, 21(8): 457-65.
[7] Miyoshi N, Wagatsuma H, Wakana S, et al. Identification of an Imprinted Gene, Meg3/Gtl2 and Its Human Homologue MEG3, First Mapped on Mouse Distal Chromosome 12 and Human Chromosome 14q[J]. Genes to Cells. 2000, 5(3): 211-220.
[8] Kuzmin A, Han Z M, Golding M C, et al. The Pcg Gene Sfmbt2 Is Paternally Expressed in Extraembryonic Tissues[J]. Gene Expression Patterns. 2008, 8(2): 107-116.
[9] Yang T, Adamson T E, Resnick J L, et al. A Mouse Model for Prader-Willi Syndrome Imprinting-Centre Mutations[J]. Nat Genet. 1998, 19(1): 25-31.
[10] Reik W, Walter J. Genomic Imprinting: Parental Influence on the Genome[J]. Nat Rev Genet. 2001, 2(1): 21-32.
[11] Reed M L, Leff S E. Maternal Imprinting of Human SNRPN, a Gene Deleted in Prader-Willi Syndrome[J]. Nature Genetics. 1994, 6(2): 163-7.
[12] Jay P, Rougeulle C, Massacrier A, et al. The Human Necdin Gene, NDN, Is Maternally Imprinted and Located in the Prader-Willi Syndrome Chromosomal Region[J]. Nature Genetics. 1997, 17(3): 357-61.
[13] Lee S, Kozlov S, Hernandez L, et al. Expression and Imprinting of Magel2 Suggest a Role in Prader-Willi Syndrome and the Homologous Murine Imprinting Phenotype[J]. Hum Mol Genet. 2000, 9(12): 1813-9.
[14] Wevrick R, Francke U. An Imprinted Mouse Transcript Homologous to the Human Imprinted in Prader-Willi Syndrome (Ipw) Gene[J]. Hum Mol Genet. 1997, 6(2): 325-32.
[15] Rougeulle C, Cardoso C, Fontes M, et al. An Imprinted Antisense RNA Overlaps Ube3a and a Second Maternally Expressed Transcript[J]. Nature Genetics. 1998, 19(1): 15-6.
[16] Herzing L B, Kim S J, Cook E H, Jr., et al. The Human Aminophospholipid-Transporting ATPase Gene ATP10C Maps Adjacent to UBE3A and Exhibits Similar Imprinted Expression[J]. Am J Hum Genet. 2001, 68(6): 1501-5.
[17] Reik W, Walter J. Genomic Imprinting: Parental Influence on the Genome[J]. Nature Reviews Genetics. 2001, 2(1): 21-32.
[18] Yang T, Adamson T E, Resnick J L, et al. A Mouse Model for Prader-Willi Syndrome Imprinting-Centre Mutations[J]. Nature Genetics. 1998, 19(1): 25-31.
[19] Neumann B, Kubicka P, Barlow D P. Characteristics of Imprinted Genes, (Vol 9, Pg 12, 1995)[J]. Nature Genetics. 1995, 9(4): 451-451.
[20] Guillemot F, Caspary T, Tilghman S M, et al. Genomic Imprinting of Mash2, a Mouse Gene Required for Trophoblast Development[J]. Nature Genetics. 1995, 9(3): 235-42.
[21] Lee J T, Jaenisch R. The (Epi)Genetic Control of Mammalian X-Chromosome Inactivation[J]. Curr Opin Genet Dev. 1997, 7(2): 274-80.
[22] Hikichi T, Kohda T, Kaneko-Ishino T, et al. Imprinting Regulation of the Murine Meg1/Grb10 and Human Grb10 Genes; Roles of Brain-Specific Promoters and Mouse-Specific Ctcf-Binding Sites[J]. Nucleic Acids Research. 2003, 31(5): 1398-406.
[23] Reinhart B, Eljanne M, Chaillet J R. Shared Role for Differentially Methylated Domains of Imprinted Genes[J]. Mol Cell Biol. 2002, 22(7): 2089-98.
[24] Ferguson-Smith A C, Sasaki H, Cattanach B M, et al. Parental-Origin-Specific Epigenetic Modification of the Mouse H19 Gene[J]. Nature. 1993, 362(6422): 751-5.
[25] Kitsberg D, Selig S, Brandeis M, et al. Allele-Specific Replication Timing of Imprinted Gene Regions[J]. Nature. 1993, 364(6436): 459-63.
[26] Sleutels F, Zwart R, Barlow D P. The Non-Coding Air RNA Is Required for Silencing Autosomal Imprinted Genes[J]. Nature. 2002, 415(6873): 810-813.
[27] Yoon B, Herman H, Hu B, et al. Rasgrf1 Imprinting Is Regulated by a Ctcf-Dependent Methylation-Sensitive Enhancer Blocker[J]. Molecular and Cellular Biology. 2005, 25(24): 11184-11190.
[28] Santos-Rosa H, Caldas C. Chromatin Modifier Enzymes, the Histone Code and Cancer[J]. Eur J Cancer. 2005, 41(16): 2381-402.
[29] Kouzarides T. Chromatin Modifications and Their Function[J]. Cell. 2007, 128(4): 693-705.
[30] Kim J K, Samaranayake M, Pradhan S. Epigenetic Mechanisms in Mammals[J].Cell Mol Life Sci. 2009, 66(4): 596-612.
[31] Pauler F M, Koerner M V, Barlow D P. Silencing by Imprinted Noncoding Rnas: Is Transcription the Answer?[J]. Trends in Genetics. 2007, 23(6): 284-292.
[32] Shastry B S. SNP Alleles in Human Disease and Evolution[J]. J Hum Genet. 2002, 47(11): 561-6.
[33] Khatib H. Imprinting of Nesp55 Gene in Cattle[J]. Mammalian Genome. 2004, 15(8): 663-7.
[34] Ono R, Shiura H, Aburatani H, et al. Identification of a Large Novel Imprinted Gene Cluster on Mouse Proximal Chromosome 6[J]. Genome Research. 2003, 13(7): 1696-705.
[35] Evans H K, Wylie A A, Murphy S K, et al. The Neuronatin Gene Resides in a "Micro-Imprinted" Domain on Human Chromosome 20q11.2[J]. Genomics. 2001, 77(1-2): 99-104.
[36] Kaneko-Ishino T, Kuroiwa Y, Miyoshi N, et al. Peg1/Mest Imprinted Gene on Chromosome 6 Identified by Cdna Subtraction Hybridization[J]. Nature Genetics. 1995, 11(1): 52-9.
[37] Kuroiwa Y, Kaneko-Ishino T, Kagitani F, et al. Peg3 Imprinted Gene on Proximal Chromosome 7 Encodes for a Zinc Finger Protein[J]. Nature Genetics. 1996, 12(2): 186-90.
[38] Kagitani F, Kuroiwa Y, Wakana S, et al. Peg5/Neuronatin Is an Imprinted Gene Located on Sub-Distal Chromosome 2 in the Mouse[J]. Nucleic Acids Research. 1997, 25(17): 3428.
[39] Miyoshi N, Kuroiwa Y, Kohda T, et al. Identification of the Meg1/Grb10 Imprinted Gene on Mouse Proximal Chromosome 11, a Candidate for the Silver-Russell Syndrome Gene[J]. Proc Natl Acad Sci U S A. 1998, 95(3): 1102-7.
[40] Piras G, El Kharroubi A, Kozlov S, et al. Zac1 (Lot1), a Potential Tumor Suppressor Gene, and the Gene for Varepsilon-Sarcoglycan Are Maternally Imprinted Genes: Identification by a Subtractive Screen of Novel Uniparental Fibroblast Lines[J]. Molecular and Cellular Biology. 2000, 20(9): 3308.
[41] Jayapal M, Melendez A J. DNA Microarray Technology for Target Identification and Validation[J]. Clin Exp Pharmacol Physiol. 2006, 33(5-6): 496-503.
[42] Yan P S, Chen C M, Shi H, et al. Dissecting Complex Epigenetic Alterations in Breast Cancer Using Cpg Island Microarrays[J]. Cancer Research. 2001, 61(23): 8375.
[43] Kobayashi S, Wagatsuma H, Ono R, et al. Mouse Peg9/Dlk1 and Human PEG9/DLK1 Are Paternally Expressed Imprinted Genes Closely Located to the Maternally Expressed Imprinted Genes: Mouse Meg3/Gtl2 and Human MEG3[J]. Genes to Cells. 2000, 5(12): 1029-37.
[44] Mizuno Y, Sotomaru Y, Katsuzawa Y, et al. Asb4, Ata3, and Dcn Are NovelImprinted Genes Identified by High-Throughput Screening Using Riken Cdna Microarray[J]. Biochem Biophys Res Commun. 2002, 290(5): 1499-505.
[45] Schulz R, Menheniott T R, Woodfine K, et al. Chromosome-Wide Identification of Novel Imprinted Genes Using Microarrays and Uniparental Disomies[J]. Nucleic Acids Research. 2006, 34(12): e88.
[46] Hagiwara Y, Hirai M, Nishiyama K, et al. Screening for Imprinted Genes by Allelic Message Display: Identification of a Paternally Expressed Gene Impact on Mouse Chromosome 18[J]. Proc Natl Acad Sci U S A. 1997, 94(17): 9249-54.
[47]张凤伟.猪七个候选印记基因的分离、印记鉴定及其与性状的关联分析[J].华中农业大学学位论文. 2007.
[48] Hatada I, Hayashizaki Y, Hirotsune S, et al. A Genomic Scanning Method for Higher Organisms Using Restriction Sites as Landmarks[J]. Proc Natl Acad Sci U S A. 1991, 88(21): 9523-7.
[49] Kawai J, Hirotsune S, Hirose K, et al. Methylation Profiles of Genomic DNA of Mouse Developmental Brain Detected by Restriction Landmark Genomic Scanning (Rlgs) Method[J]. Nucleic Acids Research. 1993, 21(24): 5604-8.
[50] Hayashizaki Y, Shibata H, Hirotsune S, et al. Identification of an Imprinted U2af Binding Protein Related Sequence on Mouse Chromosome 11 Using the Rlgs Method[J]. Nature Genetics. 1994, 6(1): 33-40.
[51] Plass C, Shibata H, Kalcheva I, et al. Identification of Grf1 on Mouse Chromosome 9 as an Imprinted Gene by Rlgs-M[J]. Nat Genet. 1996, 14(1): 106-9.
[52] Smith R J, Dean W, Konfortova G, et al. Identification of Novel Imprinted Genes in a Genome-Wide Screen for Maternal Methylation[J]. Genome Research. 2003, 13(4): 558-69.
[53] Gall J G, Pardue M L. Formation and Detection of RNA-DNA Hybrid Molecules in Cytological Preparations[J]. Proc Natl Acad Sci U S A. 1969, 63(2): 378-83.
[54] Buongiorno-Nardelli M, Amaldi F. Autoradiographic Detection of Molecular Hybrids between RNA and DNA in Tissue Sections[J]. Nature. 1970, 225(5236): 946-8.
[55] Orth G, Jeanteur P, Croissant O. Evidence for and Localization of Vegetative Viral DNA Replication by Autoradiographic Detection of RNA-DNA Hybrids in Sections of Tumors Induced by Shope Papilloma Virus[J]. Proceedings of the National Academy of Sciences. 1971, 68(8): 1876.
[56] Bauman J, Wiegant J, Borst P, et al. A New Method for Fluorescence Microscopical Localization of Specific DNA Sequences by in Situ Hybridization of Fluorochrome-Labelled RNA[J]. Experimental Cell Research. 1980, 128(2): 485-490.
[57] Langer-Safer P R, Levine M, Ward D C. Immunological Method for MappingGenes on Drosophila Polytene Chromosomes[J]. Proceedings of the National Academy of Sciences. 1982, 79(14): 4381.
[58] Ohlsson R, Hedborg F, Holmgren L, et al. Overlapping Patterns of Igf2 and H19 Expression During Human Development: Biallelic Igf2 Expression Correlates with a Lack of H19 Expression[J]. Development. 1994, 120(2): 361.
[59] Li T, Vu T H, Zeng Z L, et al. Tissue-Specific Expression of Antisense and Sense Transcripts at the Imprinted Gnas Locus* 1[J]. Genomics. 2000, 69(3): 295-304.
[60] Jiang S, Hemann M A, Lee M P, et al. Strain-Dependent Developmental Relaxation of Imprinting of an Endogenous Mouse Gene, Kvlqt1[J]. Genomics. 1998, 53(3): 395-399.
[61] Yevtodiyenko A, Carr M S, Patel N, et al. Analysis of Candidate Imprinted Genes Linked to Dlk1-Gtl2 Using a Congenic Mouse Line[J]. Mammalian Genome. 2002, 13(11): 633-8.