소 착상 전 초기수정란에서 Oct-4 유전자 Promoter 영역의 DNA 메틸화 변화

DNA Methylation Change of Oct-4 Gene Promoter Region during Bovine Preimplantation Early Embryos

  • 고응규 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 김종무 (충북대학교 축산학과) ;
  • 김동훈 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 차병현 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 황성수 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 양병철 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 임기순 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 김명직 (농촌진흥청 축산과학원 응용생명공학과) ;
  • 민관식 (한경대학교 생물환경정보통신전문대학원) ;
  • 성환후 (농촌진흥청 축산과학원 응용생명공학과)
  • 발행 : 2008.03.31

초록

DNA 메틸화는 조직특이적인 유전자 조절에 관여하고, 정상적인 배 발달에 필수적이다. POU5F1은 octamer-binding transcription factor 4 (Oct-4)를 encode하며, 초기 분화에 중요한 전사인자이다. 본 실험에서 소의 Oct-4가 조직특이적이고 발달의존적인 epigenetic 표지 인지를 검토하고자, 착상 전 수정란에서 Oct-4 전사산물과 상류 promoter 영역의 CpGs의 메틸화를 조사하였다. Oct-4 전사산물은 정자 그리고 2-cell에서 8-cell 수정란까지 낮은 수준으로 존재하지만, 상실배와 배반포에서 높게 검출되었다. 이러한 결과는 배 발달 과정의 상실배 단계에서 Oct-4의 de novo 발현이 시작됨을 의미한다. Oct-4 상류 promoter 영역에는 메틸화 가변 영역 (tissue-dependent differentially methylated region, T-DMR)이 존재한다. Oct-4 메틸화 가변 영역의 메틸화 상태는 정자, 성체 체조직과 난자에서 서로 다르고, 수정란으로부터 배반포 단계까지 변화하였는데, 이는 착상 전 초기 배 발달 과정에 active 메틸화와 탈메틸화가 일어남을 의미한다. 이상의 결과, Oct-4 유전자 상류 promoter 영역은 DNA 메틸화의 타깃이고, 그 메틸화 상태는 소 수정란 발달 동안에 다양하게 변화한다.

DNA methylation is involved in tissue-specific gene control and essential for normal embryo development Octamer-binding transcription factor 4 (Oct-4) is one of the most important transcription factors for early differentiation. This study was performed whether the bovine Oct-4 is tissue specific or developmental dependent epigenetic mark, we investigated transcripts and the methylation status of CpGs of 5'-promoter region of Oct-4 in bovine preimplantation embryos. Oct-4 transcripts were highly detected in morula and blastocyst, while they were present low levels in sperm and 2- to 8-cell stage embryos. These results suggest that de novo expression of Oct-4 initiates at morula stage of embryogenesis. Here we determined that there is a tissue-dependent differentially methylated region (T-DMR) in the 5'-promoter region of Oct-4. The methylation status of the Oct-4 T-DMR was distinctively different in the oocyte from that in the sperm and adult somatic tissues and changed from zygote to blastocyst stage, suggesting that active methylation and demethylation occur during preimplantation development. Based on these results, the 5'-promoter region of Oct-4 gene is target for DNA methylation and the methylation status changes variously during embryonic development in bovine.

키워드

참고문헌

  1. Aoki F, Worrad DM, Schultz RM (1997): Regulation of transcriptional activity during the first and second cell cycles in the preimplantation mouse embryo. Dev Biol 181:296-307 https://doi.org/10.1006/dbio.1996.8466
  2. Aoki F, Hara KT, Schultz RM (2003): Acquisition of transcriptional competence in the 1-cell mouse embryo: requirement for recruitment of maternal m-RNAs. Mol Reprod Dev 64:270-274 https://doi.org/10.1002/mrd.10227
  3. Barnea E, Bergman Y (2000): Synergy of SF1 and RAR in activation of Oct-3/4 promoter. J Biol Chem 275:6608-6619 https://doi.org/10.1074/jbc.275.9.6608
  4. Beaujean N, Taylor JE, McGarry M, Gardner JO, Wilmut I, Loi P, Ptak G, Galli C, Lazzari G, Bird A, Young LE, Meehan, RR (2004): The effect of interspecific oocytes on demethylation of sperm DNA. Proc Natl Acad Sci USA 101:7636-7640
  5. Bird AP, Wolffe AP (1999): Methylation-induced repression-belts, braces, and chromatin. Cell 99:451-454 https://doi.org/10.1016/S0092-8674(00)81532-9
  6. Clark SJ, Harrison J, Paul CL, Frommer M (1994): High sensitivity mapping of methylated cytosines. Nucleic Acids Res 22:2990-2997 https://doi.org/10.1093/nar/22.15.2990
  7. Dean W, Santos F, Stojkovic M, Zakhartchenko V, Walter J, Wolf E, Reik W (2001): Conservation of methylation reprogramming in mammalian development: aberrant reprogramming in cloned embryos. Proc Natl Acad Sci USA 98:13734-13738
  8. Fuhrmann G, Sylvester, Scholer HR (1999): Repression of Oct-4 during embryonic cell differentiation correlates with the appearance of TRIF, a transiently induced DNA-binding factor. Cell Mol Biol (Noisyle-grand) 45:717-724
  9. Fuhrmann G, Chung AC, Jackson KJ, Hummelke G, Baniahmad A, Sutter J, Sylvester I, Scholer HR, Cooney AJ (2001): Mouse germline restriction of Oct-4 expression by germ cell nuclear factor. Dev Cell 1:377-387 https://doi.org/10.1016/S1534-5807(01)00038-7
  10. Fulka H, Mrazek M, Tepla O, Fulka JJr (2004): DNA methylation pattern in human zygotes and developing embryos. Reproduction 128:703-708 https://doi.org/10.1530/rep.1.00217
  11. Hattori N, Nishino K, Ko YG, Ohgane J, Tanaka S, Shiota K (2004): Epigenetic control of mouse Oct-4 gene expression in embryonic stem cells and trophoblast stem cells. J Biol Chem 279:17063-17069 https://doi.org/10.1074/jbc.M309002200
  12. Kim JM, Ko YG, Seong HH, Chung HJ, Chang WK, Kim NH (2007): Alteration of DNA methylation in Oct-4 gene in mouse preimplantation embryos by the interference RNA. Reprod Dev Biol 31:21-28
  13. Kirchhof N, Carnwath JW, Lemme E, Anastassiadis K, Scholer H, Niemann H (2000): Expression pattern of Oct-4 in preimplantation embryos of different species. Biol Reprod 63:1698-1705 https://doi.org/10.1095/biolreprod63.6.1698
  14. Ko YG, Nishino K, Hattori N, Arai Y, Tanaka S, Shiota K (2005): Stage-by-Stage Change in DNA Methylation Status of Dnmt1 Locus during mouse early development. J Biol Chem 280:9627-9634 https://doi.org/10.1074/jbc.M413822200
  15. Kurosaka S, Eckardt S, John, MK (2004): Pluripotent lineage definition in bovine embryos by Oct-4 transcript localization. Biol Reprod 71:1578-1582 https://doi.org/10.1095/biolreprod.104.029322
  16. Marikawa Y, Fujita TC, Alarco'n VB (2005): Heterogeneous DNA methylation status of the regulatory element of the mouse Oct-4 gene in adult somatic cell population. Cloning Stem Cells 7:8-16 https://doi.org/10.1089/clo.2005.7.8
  17. Nichols J, Zevnik B, Anastassiadis K, Niwa H, Klewe-Nebenius D, Chambers I, Scholer H, Smith A (1998): Formation of pluripotent stem cells in the mammalian embryo depends on the POU transcription factor Oct-4. Cell 95:379-391 https://doi.org/10.1016/S0092-8674(00)81769-9
  18. Niwa H, Miyazaki J, Smith AG. (2000): Quantitative expression of Oct-3/4 defines differentiation, dedifferentiation or self-renewal of ES cells. Nat Genet 24:372-376 https://doi.org/10.1038/74199
  19. Nordhoff V, Hubner K, Bauer A, Orlova I, Malapesta A, Scholer HR (2001): Comparative analysis of human, bovine, and murine Oct-4 upstream promoter sequences. Mamm Genome 12:309-317 https://doi.org/10.1007/s003350010279
  20. Okamoto K, Okazawa H, Okuda A, Sakai M, Muramatsu M, Hamada H (1990): A novel octamer biing transcription factor is differentially expressed in mouse embryonic cells. Cell 60:461-472 https://doi.org/10.1016/0092-8674(90)90597-8
  21. Okazawa H, Okamoto K, Ishino F, Ishino-Kaneko T, Takeda S, Toyoda Y, Muramatsu M, Hamada H (1991): The oct3 gene, a gene for an embryonic transcription factor, is controlled by a retinoic acid repressible enhancer. Embo J 10:2997-3005
  22. Oswald J, Engemann S, Lane N, Mayer W, Olek A, Fundele R, Dean W, Reik W, Walter J (2000): Active demethylation of the paternal genome in the mouse zygote. Curr Biol 10:475-478 https://doi.org/10.1016/S0960-9822(00)00448-6
  23. Pesce M, Marin Gomez M, Philipsen S, Scholer HR (1999): Binding of Sp1 and Sp3 transcription factors to the Oct-4 gene promoter. Cell Mol Biol (Noisyle-grand) 45:709-716
  24. Rosner MH, Vigano MA, Ozato K, Timmons PM, Poirier F, Rigby PW, Staudt LM (1990): A POU-domain transcription factor in early stem cells and germ cells of the mammalian embryo. Nature 345:686-692 https://doi.org/10.1038/345686a0
  25. Rougier N, Bourc'his D, Gomes DM, Niveleau A, Plachot M, Paldi A, Viegas-Pequignot E (1998): Chromosome methylation patterns during mammalian preimplantation development. Genes Dev 12:2108-2113 https://doi.org/10.1101/gad.12.14.2108
  26. Santos F, Hendrich B, Reik W, Dean W (2002): Dynamic reprogramming of DNA methylation in the early mouse embryo. Dev Biol 241:172-82 https://doi.org/10.1006/dbio.2001.0501
  27. Scholer HR, Ruppert S, Suzuki N, Chowdhury K, Gruss P (1990): New type of POU domain in germ line-specific protein Oct-4. Nature 344:435-439 https://doi.org/10.1038/344435a0
  28. Shiota K, Kogo Y, Ohgane J, Imamura T, Urano A, Nishino K, Tanaka S, Hattori N (2002): Epigenetic marks by DNA methylation specific to stem, germ and somatic cells in mice. Genes Cells 7:961-969 https://doi.org/10.1046/j.1365-2443.2002.00574.x
  29. Tanaka S, Kunath T, Hadjantonakis AK, Nagy A, Rossant J (1998): Promotion of trophoblast stem cell proliferation by FGF4. Science 282:2072-2075 https://doi.org/10.1126/science.282.5396.2072
  30. Van Eijk MJ, van Rooijen MA, Modina S, Scesi L, Folkers G, van Tol HT, Bevers MM, Fisher SR, Lewin HA, Rakacolli D, Galli C, de Vaureix C, Trounson AO, Mummery CL, Gandolfi F (1999): Molecular cloning, genetic mapping, and developmental expression of bovine POU5F1. Biol Reprod 60:1093-1103 https://doi.org/10.1095/biolreprod60.5.1093
  31. Vigneault C, McGraw S, Massicotte L, Sirard MA (2004): Transcription factor expression patterns in bovine in vitro-derived embryos prior to maternalzygotic transition. Biol Reprod 70:1701-1709 https://doi.org/10.1095/biolreprod.103.022970
  32. Yamazaki Y, Fujita TC, Low EW, Alarco'N VB, Yanagimachi R, Marikawa Y (2006): Gradual DNA demethylation of the Oct4 promoter in cloned mouse embryos. Mol Reprod Dev 73:180-188 https://doi.org/10.1002/mrd.20411
  33. Yeom YI, Fuhrmann G, Ovitt CE, Brehm A, Ohbo K, Gross M, Hubner K, Scholer HR (1996): Germline regulatory element of Oct-4 specific for the totipotent cycle of embryonal cells. Development 122:881-894