克隆绵羊印记相关基因的DNA甲基化研究
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摘要
体细胞核移植技术在医疗、农业及畜牧业等诸多领域有重要的应用价值。尽管利用该技术已经成功获得了多种克隆动物,但随之而来的克隆胚胎及个体成活率低、不同种属普遍存在的LOS(large offspring syndrome)等异常制约了体细胞核移植技术的广泛应用。目前,有许多学者认为不完全表观重编程是克隆效率低下的原因。本研究通过检测新生死亡克隆绵羊印记相关基因的DNA甲基化水平,探究克隆绵羊DNA甲基化的重编程程度。
     本研究主要采用重亚硫酸盐修饰测序法(BSP)和甲基化特异性PCR(MSP)法检测了2-3日龄死亡克隆蒙古绵羊肾脏、肺脏、肝脏、心脏和肌肉组织中8个印记相关基因的DNA甲基化水平与正常对照的异同,其中克隆个体羔羊2只,正常对照2只。此外,本研究进一步比较分析了Igf2r、Dlk1、Xist和Peg10在克隆绵羊D2和正常对照五种组织中的mRNA表达情况。在进行上述分析之前,本研究首先克隆了部分基因片段。通过实验得到如下结果:
     (1)本研究成功克隆到了绵羊Peg10 1163bp的拟DMR序列(GI:269838596),848bp绵羊Peg10部分cDNA序列(GI:285014443),764bp的绵羊Xist第一外显子5’端序列及483bp的cDNA序列(GI:285014445),307bp的绵羊Peg3第一外显子5’端序列。
     (2)绵羊Peg10 5’端CpG岛内205bp范围内区域为差异甲基化区域。
     (3)绵羊Peg3外显子5’端CpG岛内232bp范围内11个CpG二核苷酸对上的胞嘧啶在2-3日龄绵羊肾脏和肺脏中基本完全甲基化。
     (4)绵羊Cdkn1c外显子5’端CpG岛内188bp范围内19个CpG二核苷酸对上的胞嘧啶在2-3日龄绵羊肾脏和肺脏中基本非甲基化。
     (5)绵羊Dlk1转录起始位点上游CpG岛内188bp范围内17个CpG二核苷酸对上的胞嘧啶甲基化模式为马赛克式,该区域并非差异甲基化区域。
     (6)绵羊H19启动子区CpG岛内CTCF结合位点III附近121bp范围内6个CpG二核苷酸对上的胞嘧啶甲基化模式为马赛克式,该区域并非差异甲基化区域。
     (7)克隆绵羊D1、D2各组织各印记相关基因的DNA甲基化模式与正常对照基本相同,无明显差异,仅D2个别组织Dlk1甲基化水平略高于正常对照,D2 H19肝组织的甲基化水平高于对照。
     (8)克隆绵羊Xist MSP甲基化结果显示绵羊Xist分析区域可能为差异甲基化区域,而且克隆绵羊的甲基化模式与正常对照无显著差异。
     (9)半定量RT-PCR结果显示绵羊Xist和Igf2r基因表达基本无组织差异性,而Peg10的mRNA表达表现组织特异性,肾脏中表达水平强于其他组织。
     (10)Peg10和Dlk1在新生个体组织中的mRNA表达水平比其他检测基因弱。
     (11)克隆绵羊D2肾脏、肺脏、肝脏、心脏和肌肉组织中Xist、Peg10、Dlk1和Igf2r基因mRNA的表达水平与正常对照相比,差异不显著。
     综上,本研究认为2只体细胞克隆绵羊的DNA甲基化水平与自然生产绵羊无显著差别,即体细胞核移植克隆绵羊经历了比较完全的DNA甲基化重编程。同时,克隆个体上述基因的mRNA表达水平也未表现出明显异常,暗示体细胞核移植克隆绵羊经历了比较彻底地重编程。
Somatic cell nuclear transfer (SCNT) has been successfully applied to many mammalian species. In spite of these remarkable achievements, this valuable technique has raised many questions such as increased abortion rate, perinatal death, low pregnancy rates and increased fetal and placental abnormalities, named as large offspring syndrome(LOS). Till recently, abnormal epigenetic modifications, such as DNA methylation, histone modifications and chromatin reconstructions have been reported in several cloned species. In the present study, in order to show the reprogramming degree of cloned lambs, we investigated DNA methylation patterns in CpG islands and DMR of eight imprinted and putative imprinted genes in five tissues of cloned lambs.
     BSP and MSP were used as the methods of DNA methylation analysis in this study. Five tissues of two cloned lambs died after birth and two natural produced lambs were investigated, including lung, heart, kidney, liver and muscle. Moreover, several fragments of putative imprinted genes were purified and submitted to Gene Bank. mRNA expression profiles of Igf2r、Dlk1、Xist and Peg10 in five tissues of cloned lamb D2 were also examined in this study. The results were as follows:
     (1)A 1163bp fragment of ovine Peg10 was purified(GI:269838596),a 848bp partial cDNA of ovine Peg10(GI:285014443),a 764bp 5’region of ovine Xist, a 483bp partial cDNA of ovine Xis(tGI:285014445) and a 307bp partial sequence of ovine Peg3.
     (2)A 205bp fragment in CpG island of ovine Peg10 was differential methylated.
     (3)Eleven consecutive CpG sites in CpG island of ovine Peg3 were all methylated in tissues of ovine lung and kidney.
     (4)Nineteen consecutive CpG sites in CpG island of ovine Cdkn1c were all nonmethylated in tissues of ovine lung and kidney.
     (5)DNA methylation pattern of seventeen consecutive CpG sites in CpG island of ovine Dlk1 was mosaic in all tissues. It was not a differential methylated region.
     (6)DNA methylation pattern of six consecutive CpG sites in CpG island of ovine H19 was mosaic in all tissues. It was not a differential methylated region.
     (7)The DNA methylation of putative imprinted genes of cloned lamb D1、D2 were nearly same as controls,and there were not evident differences between cloned lambs and controls except that the DNA methylation of Dlk1 and H19 in few tissues of cloned lamb D2 showed higher Methylation.
     (8)The MSP results of Xist showed that the analyzed region of ovine Xist gene is a putative differential methylated region and there were not evident differences of DNA methylation pattern between cloned sheep and controls.
     (9)The RT-PCR results of ovine Peg10 and Dlk1 exhibited that their expression were tissue specific.
     (10)The mRNA expression of Peg10 and Dlk1 in newborn lamb were weak than other examined genes.
     (11)The mRNA expression of Xist、Peg10、Dlk1 and Igf2r in tissues of cloned lamb D2 were nearly same as controls.
     In a word,there were not evident differences of DNA methylation and mRNA expression profiles between cloned lambs and controls. And somatic cell nuclear transfer sheep experienced relatively completed DNA methylation reprogramming.
引文
1 Spemann H. Entwicklungsphysiologische Studien am Tritonei II[J]. Arch f Entw Mech, 1902, Vol.15:448-453
    2 Briggs R, King T J. Transplantation of living nuclei from blastula cells into enucleated frogs eggs[J]. Proc Natl Acad Sci, 1952, Vol.38:455-463
    3 Willadsen S M, Godke R A. A simple procedure for the production of identical sheep twins[J]. The Veterinary Recor,1984,Vol.114(10):240-243
    4 Steen M, Willadsen. Cloning of sheep and cow embryos[J]. Genome, 1989, Vol.2:956-962
    5 Sims M, First N L. Production of calves by transfer of nuclei from cultured inner cell mass cells[J].Proc Natl Acad Sci,1993, Vol.91:6143-6147
    6 Campbell K H, McWhir J, Ritchie W A, et al. Sheep cloned by nuclear transfer from a cultured cell line[J]. Nature, 1996, Vol.380(6569):64-66
    7 Kato Y, Tani T, Sotomaru Y, et al. Eight calves cloned from somatic cells of a single adult[J]. Science, 1998, Vol.282(5396):2095-2098
    8 Baguisi A, Behboodi E, Melican D T, et al.Production of goats by somatic cell nuclear transfer[J]. Nat Biotechnol, 1999, Vol.17(5):456-461
    9 Vogel G. Mice cloned from cultured stem cells[J]. Science, 1999, Vol.286(5449):2437
    10 Polejaeva I A, Chen S H, Vaught T D, et al. Cloned pigs produced by nuclear transfer from adult somatic cells[J]. Nature, 2000, Vol.407(6800):86-90
    11 Kitiyanant Y, Saikhun J, Chaisalee B, et al. Somatic cell cloning in Buffalo (Bubalus bubalis): effects of interspecies cytoplasmic recipients and activation procedures[J]. Cloning Stem Cells, 2001,Vol.3(3):97-104
    12 Vogel G. Cloned gaurus with a short-lived success[J].Science,2001, Vol.291:409
    13 Loi P, Ptak G, Barboni B, et al. Genetic rescue of an endangered mammal by cross-species nuclear transfer using post-mortem somatic cells[J]. Nature Biotechnology, 2001, Vol.19:962-964
    14 Shin T, Kraemer D, Pryor J, et al. A cat cloned by nuclear transplantation[J]. Nature, 2002, Vol.415(6874):859
    15 ChesnéP, Adenot P G, Viglietta C, et al. Cloned rabbits produced by nuclear transfer from adult somatic cells[J]. Nature Biotechnology, 2002, Vol.20(4):366-369
    16 Zhou Q, Renard J P, Le Friec G, et al. Generation of fertile cloned rats by regulating oocyte activation[J]. Science, 2003, Vol.302(5648):1179
    17 Woods G L, White K L, Vanderwall D K, et al. A mule cloned from fetal cells by nucleartransfer[J]. Science, 2003, Vol.301(5636):1063
    18 Galli C, Lagutina I, Crotti G, et al. Pregnancy: a cloned horse born to its dam twin[J]. Nature, 2003, Vol.424(6949):635
    19 Li,Z, J F Engelhardt. Progress toward generating a ferret model of cystic fibrosis by somatic cell nuclear transfer[J]. Reproduction Biology Endocrinol, 2003, Vol.1:83
    20 Gómez M C, Pope C E, Giraldo A, et al. Birth of African Wildcat cloned kittens born from domestic cats[J]. Cloning Stem Cells, 2004, Vol.6(3):247-58
    21 Eurekalert. Texas A&M scientists clone world’s first deer. Texas A&M http://www2.eurekalert.org/pub_releases/2003-12/tau-tas122203.php 2005
    22 Lee B C, Kim M K, Jang G, et al. Dogs cloned from adult somatic cells[J]. Nature, 2005, Vol.436(7051):641
    23 Thomson J A, Joseph I, Itskovitz E, et al. Stem cell lines derived from human Embryonic blastocysts[J]. Science, 1998, Vol.282:1145-1147
    24 Renbinoff B E, Pera M F, Fong C Y, et al. Embryonic stem cell lines from human blastocysts: somatic differentiation in vitro[J]. Nat BiotechnoI, 2000, Vol.18:399-404
    25 Hovaffa O, Mikkola M, Gertow K, et al. A culture system using human foreskin fibroblasts as feeder cell allows production of human embryonic stem cells[J]. Hum Reprod, 2003, Vol.18:1404-1409
    26 Toyooka Y, Tsunekawa N, Akasu R, et al. Embryonic stem cells can form germ cells in vitro[J]. Proc Natl Acad Sci, 2003, Vol.100: 11457-11462.
    27 Hubner K, Fuhrmann G S Christenson L K, et al. Derivation of oocytes from mouse embryonic stem cells[J]. Science, 2003, Vol.300:1251-1256
    28 Carpenter M K, Inokuma M S, Denham J. Enrichment of neurons and neural precursors from human embryonic stem cells[J]. Exp Neurot, 2001, Vol.172:383-397
    29 Schuldiner M, Eiges R, Eden A. Induced neuronal differentiation of human embryonic stem cells[J]. Brain Res, 2001, Vol.913:201-205
    30 Mummery C, Ostwaard D W, Doevendaus P, et al. Differentiation of human embryonic stem cells to cardiomyocytes: role of coculture with visceral endoderm-like cells[J]. Circulation, 2003, Vol.107:2733-2740
    31 Kaufman D S, Hanson E T, Lewis R L, et al. Hematopoietic colony-forming cells derived from human embryonic stem cells[J]. Proc Natl Acad Sci, 2001, Vol.98:10716-10721
    32 Assady S, Maor G, Amit M, et al. Insulin production by human embryonic stem cells[J]. Diabetes, 2001, Vol.50:1691-1697
    33 Charlie Schmidt. Belated approval of first recombinant protein from animal[J]. Nature Biotechnology, 2006, Vol.24:877
    34 Huang Y J, Huang Y, Baldassarre H, et al. Recombinant human butyrylcholinesterase from milk of transgenic animals to protect against organophosphate poisoning[J]. Proc Natl Acad Sci, 2007, Vol.104(34):13603-13608
    35 Forsberg C W, Phillips J P, Golovan S P, et al. The Enviropig physiology, performance, and contribution to nutrient management advances in a regulated environment: The leading edge of change in the pork industry[J]. J Anim Sci, 2003, Vol.81:E68-E77
    36 Niemann H, Tian X C, King W A, Lee R S. Epigenetic reprogramming in embryonic and foetal development upon somatic cell nuclear transfer cloning[J]. Reproduction, 2008, Vol.135(2):151-163
    37 Kues W A,Niemann H. The contribution of farm animals to human health[J]. Trends in Biotechnology, 2004, Vol.22:286-294
    38 Young L E, Sinclair K D, Wilmut I. Large offspring syndrome in cattle and sheep[J]. Rev Reprod, 1998, Vol.3(3):155-163
    39 Renard J, Chastant S, Chesne P, et al. Lymphoid hypoplasia and somatic cloning[J]. Lancet, 1999, Vol.353:1489-1491
    40 Tamashiro K L,Wakayama T, Blanchard R J, et al. Postnatal growth and behavioral development of mice cloned from adult cumulus cells[J]. Biology of Reproduction, 2000, Vol.63:328-234
    41 Perry A C, Wakayama T. Untimely ends and new beginnings in mouse Cloning[J]. Nature Genetics, 2002, Vol.30:243-244
    42 Young L E, Fernandes K, McEvoy T G, et al. Epigenetic change in IGF2R is associated with fetal overgrowth after sheep embryo culture[J]. Nature Genetics, 2001, Vol.27:153-154
    43 Eggan K, Akutsu H, Loring J, et al. Hybrid vigor, fetal overgrowth, and viability of mice derived by nuclear cloning and tetraploid embryo complementation[J]. Proc Natl Acad Sci, 2001, Vol.98:6209-6214
    44 Hill J R, Burghardt R C, Jones K, et al. Evidence for placental abnormality as the major cause of mortality in first-trimester somatic cell cloned bovine fetuses[J]. Biol Reprod, 2000, Vol.63:1787-1794
    45 Betthauser J, Forsberg E, et al. Production of cloned pigs from in vitro systems[J]. Nat Biotechnol, 2000,Vol.18:1055-1059
    46 Behboodi E, Ayres S L, Memili E, et al. Health and reproductive profiles of malaria antigen-producing transgenic goats derived by somatic cell nuclear transfer[J].Cloning Stem Cells, 2005, Vol.7:107-118
    47 Smith S L, Everts R E, Tian X C, et al. Global gene expression profiles reveal significant nuclear reprogramming by the blastocyst stage after cloning[J]. Proc Natl Acad Sci, 2005, Vol.102:17582-17587
    48 Brambrink T, Hochedlinger K, Bell G, et al. ES cells derived from cloned and fertilized blastocysts are transcriptionally and functionally indistinguishable[J]. Proc Natl Acad Sci, 2006, Vol.103:933-938
    49 Rodolfa K T, Eggan K. A transcriptional logic for nuclear reprogramming[J]. Cell, 2006, Vol.126(4):652-655
    50 Yamanaka S. Strategies and new developments in the generation of patient-specific pluripotent stem cells[J]. Cell Stem Cell,2007, Vol.1(1):39-49
    51 Kim J B, Zaehres H, Wu G, et al. Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors[J]. Nature, 2008, Vol.454(7204):646-650
    52 Kim J B, Sebastiano V, Wu G, et al.Oct4-induced pluripotency in adult neural stem cells[J]. Cell, 2009, Vol.136(3):411-419
    53 Yu J, Hu K, Smuga-Otto K, et al. Human induced pluripotent stem cells free of vector and transgene sequences[J]. Science, 2009, Vol.324(5928):797-801
    54 Kaji K, Norrby K, Paca A, et al. Virus-free induction of pluripotency and subsequent excision of reprogramming factors[J]. Nature, 2009, Vol.458(7239):771-775
    55 Woltjen K, Michael I P, Mohseni P, et al. piggyBac transposition reprograms fibroblasts to induced pluripotent stem cells[J]. Nature, 2009, Vol.458(7239):766-770
    56 Shen L, Kondo Y, Guo Y, et al. Genome-wide profiling of DNA methylation reveals a class of normally methylated CpG island promoters[J]. PLoS Genet, 2007, Vol.3(10):2023-2036
    57 Illingworth R, Kerr A, Desousa D, et al. A novel CpG island set identifies tissue-specific methylation at developmental gene loci[J]. PLoS Biol, 2008, Vol.6(1):e22
    58 Reik W, Dean W, Walter J. Epigenetic reprogramming in mammalian development[J]. Science, 2001, Vol.293(5532):1089-1093
    59 Feng Y Q, Desprat R, Fu H, et al. DNA methylation supports intrinsic epigenetic memory in mammalian cells[J]. PLOS Genet, 2006, Vol.2:0461-0470
    60 Dean W, Santos F, Stojkovic M, et al. Conservation of methylation reprogramming in mammalian development: aberrant reprogramming in cloned embryos[J]. PNAS, 2001,Vol.98:13734-13738
    61 Kang Y K, Koo D B, Park J S, et al. Aberrant methylation of donor genome in cloned bovine embryos[J]. Nature Genetics,2001,Vol.28:173-177
    62 Beaujean N, Taylor J, Garden J, et al. Effect of limited DNA methylation reprogramming in the normal sheep embryo on somatic cell nuclear transfer[J]. Biol Reprod, 2004, Vol.71:185-193
    63 Kang Y K, Yeo S, Kim S H, et al. Precise recapitulation of methylation change in early cloned embryos[J]. Molecular Reproduction and Development,2003,Vol.66:32-37
    64 Dindot S V, Farin P W, Farin C E, et al. Epigenetic and genomic imprinting analysis in nuclear transfer derived Bos gaurus/Bos taurus hybrid fetuses[J]. Biology of Reproduction, 2004, Vol.71:470-478
    65 Cezar G G, Bartolomei M S, Forsberg E J, et al. Genome-wide epigenetic alterations in cloned bovine fetuses[J].Biology of Reproduction, 2003, Vol.68:1009-1014
    66 Hiendleder S, Mund C, Reichenbach H D, et al. Tissue-specific elevated genomic cytosine methylation levels are associated with an overgrowth phenotype of bovine fetuses derived by in vitro techniques[J]. Biology of Reproduction, 2004, Vol.71:217-223
    67 Peterson C L, Laniel M A. Histones and histone modifications[J]. Curr Biol, 2004, Vol.14(14):R546-551
    68 Marks P, Rifkind R A, Richon V M. Histone deacetylases and cancer: causes and therapies[J]. Nat Rev Cancer, 2001, Vol.1(3):194-202
    69 Gao S, Chung Y G, Parseghian M H, et al. Rapid H1 linker histone transitions following fertilization or somatic cell nuclear transfer: evidence for a uniform developmental program in mice[J]. Dev Biol, 2004, Vol.266:62-75
    70 Teranishi T, Tanaka M, Kimoto S, et al. Rapid replacement of somatic linker histones with the oocyte-specific linker histone H1foo in nuclear transfer[J]. Dev Biol, 2004, Vol.266:76-86
    71 Shao G B, Ding H M, Gong A H, et al. Inheritance of histone H3 methylation in reprogramming of somatic nuclei following nuclear transfer[J]. J Reprod Dev, 2008, Vol.54:233-238
    72 Santos F, Zakhartchenko V, Stojkovic M, et al. Epigenetic marking correlates with developmental potential in cloned bovine preimplantation embryos[J]. Curr Biol, 2003, Vol.13:1116-1121
    73 Maalouf W E, Alberio R, Campbell K H, et al. Differential acetylation of histone H4 lysine during development of in vitro fertilized, cloned and parthenogeneticallyactivated bovine embryos[J]. Epigenetics, 2008, Vol.3:199-209
    74吴侠.牛体外受精胚胎及克隆胚胎发育过程中组蛋白修饰表观遗传重编程的研究[D].内蒙古大学博士学位论文.2008
    75 Siriaco, G, Deuring, R, Chioda, M, et al. Drosophila ISWI regulates the association of histone H1 with interphase chromosomes in vivo[J]. Genetics, 2009, Vol.182:661–669
    76 Konev A Y, Tribus M, Park S Y, et al. CHD1 motor protein is required for deposition of histone variant H3.3 into chromatin in vivo. Science, 2007, Vol.317:1087–1090
    77 Ho L, Crabtree G R. Chromatin remodelling during development[J]. Nature, 2010, Vol.463(7280):474-484
    78 Chang C C, Gao S, Sung L Y, et al. Rapid elimination of the histone variant MacroH2A from somatic cell heterochromatin after nuclear transfer[J]. Cloning Stem Cells, 2010, Vol.12(1):43-53
    79 Magnani L, Lee K, Fodor W L, et al. Developmental capacity of porcine nuclear transfer embryos correlate with levels of chromatin-remodeling transcripts in donor cells[J]. Mol Reprod Dev, 2008, Vol.75(5):766-776
    80 Reik W, Walter J. Genomic imprinting: parental influence on the genome[J]. Nat Rev Genet, 2001, Vol.2:21-32
    81 Ferguson-Smith A C, Surani M A. Imprinting and the epigenetic asymmetry between parental genomes[J]. Science, 2001, Vol.293:1086-1089
    82 Thorvaldsen J L, Bartolomei M S. SnapShot: imprinted gene clusters. Cell, 2007, Vol.130:958
    83 Charalambous M, da Rocha S T, Ferguson-Smith A C. Genomic imprinting, growth control and the allocation of nutritional resources: consequences for postnatal life[J]. Curr Opin Endocrinol Diabetes Obes, 2007, Vol.14:3-12
    84 Wilkinson L S, Davies W, Isles A R. Genomic imprinting effects on brain development and function[J]. Nat Rev Neurosci, 2007, Vol.8:832-843
    85 Ky Sha. A Mechanistic View of Genomic Imprinting[J]. Annu Rev Genomics Hum Genet, 2008, Vol.9:197-216
    86 Edwards Carol A, Ferguson-Smith Anne C. Mechanisms regulating imprinted genes in clusters[J]. Current Opinion in Cell Biology, 2007, Vol.19:281-289
    87 Cockett N E, Jackson S P, Shay T L, et al. Polar overdominance at the ovine callipyge locus[J]. Science, 1996, Vol.273:236-238
    88 Charlier C, Segers K, Karim L, et al. The callipyge mutation enhances the expression of coregulated imprinted genes in cis without affecting their imprinting status[J].Nat Genet, 2001, Vol.27:367-369
    89 Lin S P, Youngson N, Takada S, et al. Asymmetric regulation of imprinting on the maternal and paternal chromosomes at the Dlk1-Gtl2 imprinted cluster on mouse chromosome 12[J]. Nat Genet, 2003, Vol.35:97-102
    90 Davis E, Jensen C H, Schroder H D, et al. Ectopic expression of DLK1 protein in skeletal muscle of padumnal heterozygotes causes the callipyge phenotype[J]. Curr Biol, 2004, Vol.14:1858-1862
    91 Mann M R, Chung Y G, Nolen L D, et al. Disruption of imprinted gene methylation and expression in cloned preimplantation stage mouse embryos[J]. Biol Reprod, 2003, Vol.69:902-914
    92 Ogawa H, Ono Y, Shimozawa N, et al. Disruption of imprinting in cloned mouse fetuses from embryonic stem cells[J]. Reproduction, 2003, Vol.126:549-557
    93 Young L E, Schnieke A E, McCleath K J, et al. Conservation of IGF2-Hl9 and IGF2R imprinting in sheep: effects of somatic cell nuclear transfer[J]. Mech Dev, 2003, Vol.120:1433-1442
    94 Long J E,Cai X.Igf-2r expression regulated by epigenetic modification and the locus of gene imprinting disrupted in cloned cattle[J] . Gene , 2007 ,Vol.388(1-2):125-134
    95 Lucifero D,Suzuki J,Bordionon V,et al.Bovine SNRPN methylation imprint in oocytes and day 17 in vitro produced and somatic cell nuclear transfer embryos[J].Biol Reprod,2006,Vol.75(4):531-538
    96 Yang L, Chavatte P P, Kubota C, et al. Expression of imprinted genes is aberrant in deceased newborn cloned calves and relatively normal in surviving adult clones[J]. Mol Rep rod Dev, 2005, Vol.71:431-438
    97 Suzuki J Jr,Therrien,Filion F,et al.In vitro culture and somatic cell nuclear transfer affect imprinting of SNRPN gene in pre-and post-implantation stages of development in cattle[J].BMC Dev Biol,Vol.2009,Vol.9:9
    98 Payer B, Lee J T. X Chromosome Dosage Compensation: How Mammals Keep the Balance[J]. Annu Rev Genet, 2008, Vol.42:733-772
    99 Eggan K, Akutsu H, Hochedlinger K, et al.X-Chromosome inactivation in cloned mouse embryos[J]. Science, 2000,Vol.290:1578-1581
    100 Nolen L D, Gao S, Han Z, et al. X chromosome reactivation and regulation in cloned embryos[J]. Developmental Biology,2005, Vol.279:525-540
    101 Bao S, Miyoshi N, Okamoto I, et al.Initiation of epigenetic reprogramming of the X chromosome in somatic nuclei transplanted to a mouse oocyte[J]. EMBO Reports,2005, Vol.6:748-754
    102 Xue F, Tian X C, Du F, et al. Aberrant patterns of X chromosome inactivation in bovine clones[J]. Nature Genetics, 2002, Vol.31:216-220
    103 Wrenzycki C, Herrmann D, Carnwath J W, et al. Alterations in the relative abundance of gene transcripts in preimplantation bovine embryos cultured in medium supplemented with either serum or PVA[J]. Mol Reprod Dev, 1999, Vol.53:8-18
    104 Harley C B, Futcher A B, Greider C W. Telomeres shorten during ageing of human fibroblasts[J]. Nature, 1990, Vol.345:458-460
    105 De Lange T. Protection of mammalian telomeres[J]. Oncogene, 2002, Vol.21:532-540
    106 Shiels P G, Kind A J, Campbell K H. Analysis of telomere lengths in cloned sheep[J]. Nature, 1999, Vol.399:316-317
    107 Betts D H, Bordignon V, Hill J R, et al. Reprogramming of telomerase activity and rebuilding of telomere length in cloned cattle[J]. Proc Natl Acad Sci USA, 2001, Vol.98(3):1077-1082
    108 Wakayama T, Tateno H, Mombaerts P, et al. Nuclear transfer into mouse zygotes[J].Nat Genet, 2000, Vol.24(2):108-109
    109 Lanza R P, Cibelli L B,Blackwell L, et al. Extension of cell: life-span and telmere length in animals cloned from senescent somatic cells[J]. Science, 2000, 288:665-669
    110 Jeon H Y, Hyun S H, Lee G S, et al. The analysis of telomere length and telomerase activity in cloned pigs and cows[J]. Molecular Reproduction and Development, 2005, Vol.71:315-320
    111 Betts D H, Perrault S D, Petrik J, et al. Telomere length analysis in goat clones and their offspring[J]. Molecular Reproduction and Development, 2005, Vol.72:461-470
    112 Lee R S, Depree K M, Davey H W. The sheep (Ovis aries) H19 gene: genomic structure and expression patterns, from the preimplantation embryo to adulthood[J]. Gene, 2002, Vol.301(1-2):67-77
    113 Young L E, Schnieke A E, McCreath K J, et al. Conservation of IGF2-H19 and IGF2R imprinting in sheep: effects of somatic cell nuclear transfer[J]. Mech Dev, 2003, Vol.120(12):1433-1442
    114 Young L E, Fernandes K, McEvoy T G, et al. Epigenetic change in IGF2R is associated with fetal overgrowth after sheep embryo culture[J]. Nat Genet, 2001, Vol.27(2):153-154
    115 Charlier C, Segers K, Wagenaar D, et al. Human-Ovine Comparative Sequencing of a250-kb Imprinted Domain Encompassing the Callipyge (clpg) Locus and Identification of Six Imprinted Transcripts: DLK1, DAT, GTL2, PEG11, antiPEG11 ,and MEG8[J]. Genome Res,2001,Vol.11:850-862
    116 Thurston A, Taylor J, Gardner J, et al. Monoallelic expression of nine imprinted genes in the sheep embryo occurs after the blastocyst stage[J]. Reproduction, 2008,Vol.135(1):29-40
    117 Ono R, Shiura H, Aburatani H, et al. Identification of a large novel imprinted gene cluster on mouse proximal chromosome 6[J]. Genome Res, 2003, Vol.13:1696-1705
    118 Clark M B, J?nicke M, Gottesbühren U, et al. Mammalian gene PEG10 expresses two reading frames by high efficiency -1 frameshifting in embryonic-associated tissues[J]. J Biol Chem, 2007, Vol.282:37359-37369
    119 Volff J, K?rting C, Schartl M. Ty3/Gypsy retrotransposon fossils in mammalian genomes: did they evolve into new cellular functions[J]? Mol Biol Evol, 2001, Vol.18:266-270
    120 Ono R, Nakamura K, Inoue K, et al. Deletion of Peg10, an imprinted gene acquired from a retrotransposon, causes early embryonic lethality[J]. Nat Genet, 2006, Vol.38:101-106
    121 Ip W K, Lai P B, Wong N L, et al. Identification of PEG10 as a progression related biomarker for hepatocellular carcinoma[J]. Cancer Lett, 2007, Vol.250:284-291
    122 Luo JH, Ren B, Keryanov S, et al. Transcriptomic and genomic analysis of human hepatocellular carcinomas and hepatoblastomas[J]. Hepatology, 2006, Vol.44:1012-1024
    123 Tsou A P, Chuang Y C, Su J Y, et al. Overexpression of a novel imprinted gene, PEG10, in human hepatocellular carcinoma and in regenerating mouse livers[J]. J Biomed Sci,2003, Vol.10:625-635
    124 Okabe H, Satoh S, Furukawa Y, et al. Involvement of PEG10 in human hepatocellular carcinogenesis through interaction with SIAH1[J]. Cancer Res, 2003, Vol.63:3043-3048
    125 Steplewski A, Krynska B, Tretiakova A, et al. MyEF-3, a developmentally controlled brain-derived nuclear protein which specifically interacts with myelin basic protein proximal regulatory sequences[J]. Biochem Biophys Res Commun, 1998, Vol.243:295-301
    126 Smallwood A, Papageorghiou A, Nicolaides K, et al. Temporal regulation of the expression of syncytin( HERV-W) , maternally imprinted PEG10 , and SGCE in human placenta[J]. Biol Reprod, 2003, Vol.69(1):286-293
    127 Frankenberg S, Smith L, Greenfield A, et al. Novel gene expression patterns along the proximo-distal axis of the mouse embryo before gastrulation[J]. BMC Dev Biol, 2007, Vol.7:8
    128 Renfree M B, Ager E I, Shaw G, et al. Genomic imprinting in marsupial placentation[J]. Reproduction, 2008, Vol.136(5):523-531
    129 Kuroiwa Y, Kaneko-Ishino T, Kagitani F, et al. Peg3 imprinted gene on proximal chromosome 7 encodes for a zinc finger protein[J]. Nat Genet, 1996, Vol.12(2):186-190
    130 Li L, Keverne E B, Aparicio S A, et al. Regulation of maternal behavior and offspring growth by paternally expressed Peg3[J]. Science, 1999, Vol.284(5412):330-333
    131 Relaix F, Wei X J, Li W, et al. Pw1/Peg3 is a potential cell death mediator and cooperates with Siah1a in p53-mediated apoptosis[J]. Proc Natl Acad Sci USA, 2000, Vol.97(5):2105-2110
    132 Yamaguchi A, Taniguchi M, Hori O, et al. Peg3/Pw1 is involved in p53-mediated cell death pathway in brain ischemia/hypoxia[J]. J Biol Chem, 2002, Vol.277(1):623-629
    133 Champagne F A, Curley J P, Swaney W T, et al. Regulation of olfaction, anxiety and maternal behavior in mice by paternally expressed genes[J]. Hormones and Behavior, 2005, Vol.48:92-93
    134 Swaney W T, Curley J P, Champagne F A, et al. Genomic imprinting mediates sexual experience-dependent olfactory learning in male mice[J]. Proc Natl Acad Sci USA, 2007, Vol.104:6084-6089
    135 Maegawa S, et al. Epigenetic silencing of PEG3 gene expression in human glioma cell lines[J]. Mol Carcinog, 2001, Vol.31:1-9
    136 Türeci O, et al. A novel tumour associated leucine zipper protein targeting to sites of gene transcription and splicing[J]. Oncogene, 2002, Vol.21:3879-3888
    137 Kim J, et al. Discovery of a novel, paternally expressed ubiquitin-specific processing protease gene through comparative analysis of an imprinted region of mouse chromosome 7 and human chromosome 19q13.4[J]. Genome Res, 2000, Vol.10:1138-1147
    138 Kim J, Bergmann A, Wehri E, et al. Imprinting and evolution of two Kruppel-type zinc-finger genes, ZIM3 and ZNF264, located in the PEG3/USP29-imprinted domain[J]. Genomics, 2001, Vol.77:91-98
    139 Glasgow E, Ryu S L, Yamashita M, et al. A Peg3, a novel paternally expressed gene 3 antisense RNA transcript specifically expressed in vasopressinergic magnocellular neurons in the rat supraoptic nucleus[J]. Brain Res Mol Brain Res,2005, Vol.137:143-151
    140 Kim J, Lu X, Stubbs L. Zim1, a maternally expressed mouse Kruppeltype zinc-finger gene located in proximal chromosome 7[J]. Hum Mol Genet, 1999, Vol.8:847-854
    141 Kim J, Bergmann A, Lucas S, et al. Lineage-specific imprinting and evolution of the zinc-finger gene ZIM2[J]. Genomics, 2004, Vol.84(1):47-58
    142 Luo C, Lu X, Stubbs L, Kim J. Rapid evolution of a recently retroposed transcription factor YY2 in mammalian genomes[J]. Genomics, 2006, Vol.87(3):348-355
    143 Kim J, Bergmann A, Choo J H, Stubbs L. Genomic organization and imprinting of the Peg3 domain in bovine[J]. Genomics, 2007, Vol.90(1):85-92
    144 Huang J M, Kim J. DNA methylation analysis of the mammalian PEG3 imprinted domain[J]. Gene, 2009, Vol.442(1-2):18-25
    145 Kim J, Kim J D. In vivo YY1-knockdown effects on genomic imprinting[J]. Hum Mol Genet, 2008, Vol.17:391-401
    146 Hatada I, Mukai T. Genomic imprinting of p57KIP2, a cyclin dependent kinase inhibitor, in mouse[J]. Nat Genet,1995, Vol.11(2):204-206
    147 Yan Y, Frisen J, Lee M H, et al. Ablation of the CDK inhibitor p57Kip2 results in increased apoptosis and delayed differentiation during mouse development[J]. Genes Dev, 1997, Vol.11(8):973-983
    148 Engemann S, Strodicke M, Paulsen M, et al. Sequence and functional comparison in the Beckwith-Wiedemann region: implications for a novel imprinting centre and extended imprinting[J]. Hum Mol Genet, 2000, Vol.9(18):2691-2706
    149 Mancini D D, Steele S J, Levorse J M, et al. Elongation of the Kcnq1ot1 transcript is required for genomic imprinting of neighboring genes[J]. Genes Dev, 2006, Vol.20(10):1268-1282
    150 Chung W Y, Yuan L, Feng L, et al. Chromosome 11p15.5 regional imprinting: comparative analysis of KIP2 and H19 in human tissues and Wilms’tumors[J]. Hum Mol Genet, 1996, Vol.5:1101-1108
    151 Martin C, Zhang Y. The diverse functions of histone lysine Methylation[J]. Nat Rev Mol Cell Biol, 2005, Vol.6:838-849
    152 Lewis A, Mitsuya K, Umlauf D, et al. Imprinting on distal chromosome 7 in the placenta involves repressive histone methylation independent of DNA Methylation[J]. Nat Genet, 2004, Vol.36:1291-1295
    153 Silva J, Mak W, Zvetkova I, et al. Establishment of histone h3 methylation on the inactive X chromosome requires transient recruitment of Eed-Enx1 polycomb group complexes[J]. Dev Cell, 2003, Vol.4:481-495
    154 Avner P, Heard E. X-chromosome inactivation: counting, choice and initiation[J]. Nat Rev Genet, 2001, Vol.2(1):59-67
    155 Rougeulle C, Avner P. Controlling X-inactivation in mammals: what does the centre hold[J]? Sem Cell Dev Biol, 2003, Vol.14:331-340
    156 Norris D P, Patel D, Kay G F, et al. Evidence that random and imprinted Xist expression is controlled by preemptive Methylation[J]. Cell, 1994, Vol.77:41-51
    157 Zuccotti M, Monk M. Methylation of the mouse Xist gene in sperm and eggs correlates with imprinted Xist expression and paternal X-inactivation[J]. Nat. Genet, 1995, Vol.9:316-320
    158 Beard C, Li E, Jaenisch R. Loss of methylation activates Xist in somatic but not in embryonic cells[J]. Genes Dev, 1995, Vol.9(19):2325-2334
    159 Stavropoulos N, Lu N, Lee J T. A functional role for Tsix transcription in blocking Xist RNA accumulation but not in X-chromosome choice[J]. Proc Natl Acad Sci USA, 2001, Vol.98:10232-10237
    160 Nesterova T B, Johnston C M, Appanah R, et al. Skewing X chromosome choice by modulating sense transcription across the Xist locus[J]. Genes Dev, 2003, Vol.17:2177-2190
    161 Sado T, Wang Z, Sasaki H, Li E. Regulation of imprinted X chromosome inactivation in mice by Tsix[J]. Development, 2001, Vol.128:1275-1286
    162 Ogawa Y, Lee J T. Xite, X-inactivation intergenic transcription elements that regulate the probability of choice[J]. Mol Cell, 2003, Vol.11:731-743
    163 Pugacheva E M, Tiwari V K, Abdullaev Z, et al. Familial cases of point mutations in the XIST promoter reveal a correlation between CTCF binding and pre-emptive choices of X chromosome inactivation[J]. Hum Mol Genet, 2005, Vol.14:953-965
    164 Donohoe M E, Zhang L F, Xu N, et al. Identification of a Ctcf cofactor, Yy1, for the X chromosome binary switch[J]. Mol Cell, 2007, Vol.25:43-56
    165 Navarro P, Page D R, Avner P, Rougeulle C. Tsix-mediated epigenetic switch of a CTCF-flanked region of the Xist promoter determines the Xist transcription program[J]. Genes Dev, 2006, Vol.20:2787-2792
    166
    167 Moon, Y.S. et al. Mice lacking paternally expressed Pref-1/Dlk1 display growth retardation and accelerated adiposity[J]. Mol Cell Biol, 2002, Vol.22:5585-5592
    168 Lee K, Villena J A, et al. Inhibition of adipogenesis and development of glucose intolerance by soluble preadipocyte factor-1 (Pref-1)[J]. J Clin Invest, 2003, Vol.111:453-461
    169 Hernandez A, Park J P, et al. Localization of the type 3 iodothyronine deiodinase (DIO3) gene to human chromosome 14q32 and mouse chromosome 12F1[J]. Genomics, 1998, Vol.53:119-121
    170 Galton V A, Martinez E, et al. Pregnant rat uterus expresses high levels of the type 3 iodothyronine deiodinase[J]. J Clin Invest, 1999, Vol.103:979-987
    171 Kagami M, Sekita Y, Nishimura G, et al. Deletions and epimutations affecting the human 14q32.2 imprinted region in individuals with paternal and maternal UPD(14)-like phenotypes[J]. Nat Genet, 2008, Vol.40:237-242
    172 Schuster-Gossler K, Bilinski P, et al. The mouse Gtl2 gene is differentially expressed during embryonic development, encodes multiple alternatively spliced transcripts, and may act as an RNA[J]. Dev Dyn, 1998, Vol.212:214-228
    173 Takada S, Tevendale M, et al. Delta-like and gtl2 are reciprocally expressed, differentially methylated linked imprinted genes on mouse chromosome 12[J]. Curr Biol, 2000, Vol.10:1135-1138
    174 Kobayashi S, Wagatsuma H, 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 Cells, 2000, Vol.5:1029-1037
    175 Mungall A J, et al. The evolution of the Dlk1-Dio3 imprinted domain in mammals[J]. PLoS Biol, 2008, Vol.6(6):1292-1305
    176 Edwards C A, Mungall A J, Matthews L, et a1. The evolution of the Dlk1-Dio3 imprinted domain in mammals[J]. PLoS Biol, 2008, Vol.6(6):1292-1305
    177 Lin S P, Youngson N, Takada S, et a1. Asymmetric regulation of imprinting on the maternal and paternal chromosomes at the Dlk1-Gtl2 imprinted cluster on mouse chromosome 12[J]. Nat Genet, 2003, Vol.35:97-102
    178 Lin S P, Coan P, da Rocha S T, et a1. Differential regulation of imprinting in the murine embryo and placenta by the Dlk1-Dio3 imprinting control region[J]. Development, 2007, Vol.134:417-426
    179 Kagami M, Sekita Y, Nishimura G, et a1. Deletions and epimutations affecting the human 14q32.2 imprinted region in individuals with paternal and maternal UPD(14)-like phenotypes[J]. Nat Genet, 2008, Vol.40:237-242
    180 Yevtodiyenko A, Steshina E Y, Farner S C, et a1. A 178-kb BAC transgene imprints the mouse Gtl2 gene and localizes tissue-specific regulatory elements[J]. Genomics, 2004, Vol.84:277-287
    181 Davis E, Caiment F, Tordoir X, et a1. RNAi-mediated allelic trans-interaction at the imprinted Rtl1/Peg11 locus[J]. Curr Biol, 2005, Vol.15:743-749
    182 Cockett N E, Jackson S P, Shay T L, et a1. Polar overdominance at the ovine callipyge locus[J]. Science, 1996, Vol.273:236-238
    183 Charlier C, Segers K, Karim L, et a1. The callipyge mutation enhances the expression of coregulated imprinted genes in cis without affecting their imprinting status[J]. Nat Genet, 2001, Vol.27:367-369
    184 Davis E, Jensen C H, Schroder H D, et a1. Ectopic expression of DLK1 protein in skeletal muscle of padumnal heterozygotes causes the callipyge phenotype[J]. Curr Biol, 2004, Vol.14:1858-1862
    185 Bartolomei M S, Zemel S, Tilghman S M. Parental imprinting of the mouse H19 gene[J]. Nature, 1991, Vol.351:153-155
    186 Banerjee S, Smallwood A. A chromatin model of IGF2/H19 imprinting[J]. Nat Genet, 1995, Vol.11:237-238
    187 Poirier F, Chan C-TJ, Timmons P M, et a1. The murine H19 gene is activated during embryonic stem cell differentiation in vitro and at the time of implantation in the developing embryo[J]. Development,1991, Vol.113:1105-1114
    188 SzabóP E, Mann J R. Allele-specific expression and total expression levels of imprinted genes during early mouse development: Implications for imprinting mechanisms[J]. Genes Dev, 1995a, Vol.9:3097-3108
    189 Weber M, Milligan L, Delalbre A, et a1. Extensive tissue-specifi c variation of allelic methylation in the Igf2 gene during mouse fetal development: relation to expression and imprinting[J]. Mech Dev, 2001, Vol.101:133-141
    190 Ripoche M A, Kress C, Poirier F, et a1. Deletion of the H19 transcription unit reveals the existence of a putative imprinting control element[J]. Genes Dev, 1997, Vol.11:1596-1604
    191 Gao Z H, Suppola S, Liu J, et a1. Association of H19 promoter methylation with the expression of H19 and IGF-II genes in adrenocortical tumors[J]. J Clin Endocrinol Metab, 2002, Vol.87(3):1170-1176
    192 Kondo M,et a1.Altered genomic imprinting in the IGF2 and H19 genes in human lung cancer[J]. Nippon Rinsho, 1996, Vol.54(2):492-496
    193 Masashi K, Hiroko S, Kyao U. Frequent loss of imprinting of the H19 gene is often associated with its overexpression in human lung cancer[J]. Oncogene, 1995, Vol.10:1193-1198
    194 Tremblay K D, Duran K, Bartolomei M. A 5’2-kilobase- pair region of the imprinted mouse H19 gene exhibits exclusive paternal methylation throughout development[J]. Mol Cell Biol, 1997, Vol.17:4322-4329
    195 Thorvaldsen J L, Duran K L, Bartolomei M S. Deletion of the H19 differentially methylated domain results in loss of imprinted expression of H19 and Igf2[J]. Genes Dev, 1998, Vol.12:3693-3702
    196 Gabory M A, Ripoche T, Yoshimizu L, et al. The H19 gene: regulation and function of a non-coding RNA[J]. Cytogenet Genome Res, 2006, Vol.113(1-4):188-193
    197 Kato Y, Sasaki H. Imprinting and looping: epigenetic marks control interactions between regulatory elements[J]. Bioessays, 2005,Vol.27:1-4
    198 Lobel P, Dahms N M, Kornfeld S. Cloning and sequence analysis of the cation-independent mannose 6-phosphate receptor[J]. J Biol Chem, 1988, Vol.263:2563-2570
    199 Brown J, Jones E Y, Forbes B E. Interactions of IGF-II with the IGF2R/cation-independent mannose-6-phosphate receptor mechanism and biological outcomes[J]. Vitam Horm, 2009, Vol.80:699-719
    200 Ghosh P, Dahms N M, Kornfeld S. Mannose 6-phosphate receptors: New twists in the tale[J]. Nat Rev Mol Cell Biol, 2003, Vol.4:202-212
    201 Lau M M, Stewart C E, Liu Z, et al. Loss of the imprinted IGF2/cation-independent mannose 6-phosphate receptor results in fetal overgrowth and perinatal lethality[J]. Genes Dev, 1994, Vol.8:2953-2963
    202 Barlow D P, Stoger R, Herrmann B G, et al. The mouse insulin-like growth factor type-2 receptor is imprinted and closely linked to the Tme locus[J]. Nature, 1991, Vol.349:84-87
    203 Hu J F, Balaguru K A, Ivaturi R D, et al. Lack of reciprocal genomic imprinting of sense and antisense RNA of mouse insulin-like growth factor II receptor in the central nervous system[J]. Biochem Biophys Res Commun, Vol.257:604-608
    204 Xu Y, Goodyer C G, Deal C, et al. Functional polymorphism in the parental imprinting of the human IGF2R gene[J]. Biochem Biophys Res Commun, 1993, Vol.197:747-754
    205 Oudejans C B, Westerman B, Wouters D, et al. Allelic IGF2R repression does not correlate with expression of antisense RNA in human extraembryonic tissues[J]. Genomics, 2001, Vol.73:331-337
    206 Ideraabdullah F Y, Vigneau S, Bartolomei M S. Genomic imprinting mechanisms in mammals[J]. Mutat Res, 2008, Vol.647(1-2):77-85
    207 Mills J J, Falls J G, De Souza A T, et al. Imprinted M6p/Igf2 receptor is mutated in rat liver tumors[J]. Oncogene, 1998, Vol.16:2797-2802
    208 Killian J K, Nolan C M, Wylie A A, et al. Divergent evolution in M6P /IGF2R imprinting from the Jurassic to the Quaternary[J]. Hum Mol Genet, 2001c, Vol.10:1721–1728
    209 Killian J K, Byrd J C, Jirtle J V, et al. M6P / IGF2R imprinting evolution in mammals[J]. Mol Cell, 2000, Vol.5:707-716
    210 Wutz A, Smrzka O W, Schweifer N, et al. Imprinted expression of the Igf2r gene depends on an intronic CpG island[J]. Nature, 1997, Vol.389:745-749
    211 Birger Y, Shemer R, Perk J, et al. The imprinting box of the mouse Igf2r gene[J]. Nature, 1999, Vol.397:84-88
    212 Killian J K, Nolan C M, Wylie A A, et al. Divergent evolution in M6P /IGF2R imprinting from the Jurassic to the Quaternary[J].Hum Mol Genet, 2001c, Vol.10:1721-1728
    213 Yamasaki Y, Kayashima T, Soejima H, et al. Neuron-specific relaxation of Igf2r imprinting is associated with neuron-specific histone modifi cations and lack of its antisense transcript Air[J]. Hum Mol Genet, 2005, Vol.14:2511-2520
    214 Sleutels F, Zwart R, Barlow D P. The non-coding Air RNA is required for silencing autosomal imprinted genes[J]. Nature, 2002, Vol.415:810-813
    215 Nygren A O, Ameziane N, Duarte H M, et al. Methylation-specific MLPA (MS-MLPA): simultaneous detection of CpG methylation and copy number changes of up to 40 sequences[J]. Nucleic Acids Res, 2005, Vol.33(14):e128
    216 Xiong Z, Laird P W. COBRA: a sensitive and quantitative DNA methylation assay[J]. Nucleic Acids Res, 1997, Vol.25(12):2532-2534
    217 Frommer M, McDonald L E, Millar D S, et al. A genomic sequencing protocol that yields a positive display of 5-methylcytosine residues in individual DNA strands[J]. Proc Natl Acad Sci USA, 1992, Vol.89:1827-1831
    218 Gonzalgo M L, Jones P A. Quantitative methylation analysis using methylation sensitive single2nucleotide primer extension (Ms-SNuPE )[J]. Methods, 2002, Vol.27:128-133
    219 Sievers S, Alemazkour K, Zahn S, et al. IGF2PH19 imprinting analysis of human germ cell tumors ( GCTs) using the methylation-sensitive single nucleotide primer extension method reflects the origin of GCTs in different stages of primordial germ cell development[J]. Genes Chromosomes Cancer, 2005, Vol.44:256-264
    220 Maekawa M, Sugano K, Kashiwabara H, et al. DNA methylation analysis using bisulfite treatment and PCR-single-strand conformation polymorphism in colorectal cancer showing microsatellite instability[J]. Biochem Biophys Res Commun, 1999, Vol.262:671-676
    221 Aggerholm A, Guldberg P, Hokland M, et al. Extensive intra- and interindividual heterogeneity of p15INK4B methylation in acute myeloid leukemia[J]. Cancer Res, 1999, Vol.59:436-441
    222 Kent First M, Muallem A , Shultz J , et al. Defining regions of the Y2 chromosome responsible for male infertility and identification of a fourth AZF region (AZFd) by Y2 chromosome microdeletion detection[J]. Mol Reprod Dev, 1999, Vol.53:27-41
    223 Lippman Z, Gendrel A V, Colot V, et al. Profiling DNA methylation patterns using genomic tiling microarrays[J]. Nature Methods, 2005, Vol.2(3):219-224
    224 Rauch T, Li H, Wu X, et al. MIRA-assisted microarray analysis, a new technology for the determination of DNA methylation patterns, identifies frequent methylation of homeodomain-containing genes in lung cancer cells[J]. Cancer Res, 2006, Vol.66(16):7939-7947
    225 Charlier C, Segers K, Wagenaar D. Human-ovine comparative sequencing of a 250-kb imprinted domain encompassing the callipyge (clpg) locus and identification of six imprinted transcripts: DLK1, DAT, GTL2, PEG11, antiPEG11, and MEG8[J]. Genome Res, 2001, Vol.11(5):850-862
    226 Colosimo A, Di Rocco G, Curini V, et al. Characterization of the methylation status of five imprinted genes in sheep gametes[J]. Anim Genet, 2009, Aug 20
    227 Han L, Lee D H, Szabo P E, et al. CTCF is the master organizer of domain-wide allele-specific chromatin at the H19/Igf2 imprinted region[J]. Mol Cell Biol, 2008, Vol. 28:1124-1135
    228 Hark A T, et al. CTCF mediates methylation-sensitive enhancer-blocking activity at the H19/Igf2 locus[J]. Nature, 2000, Vol.405:486-489
    229 Lux H, Flammann H, Hafner M, et al. Genetic and molecular analyses of PEG10 reveal new aspects of genomic organization, transcription and translation[J]. PLoS One, 2010, Vol.5(1):e8686
    230 Shapiro M B, Senapathy P. RNA splice junctions of different classes of eukaryotes: sequence statistics and functional implications in gene expression[J]. Nucleic Acids Res, 1987, Vol.15:7155-7174

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