DOI QR코드

DOI QR Code

Phosphorylation Status of RNA Polymerase II Carboxyl-terminal Domain in Porcine Oocytes and Early Embryos

  • Oqani, Reza K. (Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University) ;
  • Zhang, Jin Yu (Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University) ;
  • Lee, Min-Gu (Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University) ;
  • Diao, Yun Fei (Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University) ;
  • Jin, Dong-Il (Department of Animal Science and Biotechnology, Research Center for Transgenic Cloned Pigs, Chungnam National University)
  • Received : 2011.10.31
  • Accepted : 2012.01.30
  • Published : 2012.06.01

Abstract

Fertilization of the oocyte commences embryogenesis during which maternally inherited mRNAs are degraded and the embryonic genome is activated. Transcription of embryonic mRNA is initiated by embryonic genome activation (EGA). RNA polymerase II (RNA Pol II) is responsible for the synthesis of mRNAs and most small nuclear RNAs, and consists of 12 subunits, the largest of which characteristically harbors a unique C-terminal domain (CTD). Transcriptional activity of RNA Pol II is highly regulated, in particular, by phosphorylation of serine residues in the CTD. Here, we have shown the presence of RNA Pol II CTD phosphoisoforms in porcine oocytes and preimplantation embryos. The distribution pattern as well as phosphorylation dynamics in germinal vesicles and during embryogenesis differed in developmental stages with these isoforms, indicating a role of RNA Pol II CTD phosphorylation at the serine residue in transcriptional activation during both oocyte growth and embryonic genome activation. We additionally examined the effects of the RNA Pol II inhibitor, ${\alpha}$-amanitin, on embryo development. Our results show that inhibition of polymerase, even at very early stages and for a short period of time, dramatically impaired blastocyst formation. These findings collectively suggest that the functionality of maternal RNA Pol II, and consequently, expression of early genes regulated by this enzyme are essential for proper embryo development.

Keywords

RNA Polymerase II;Porcine;Oocyte;Embryos;${\alpha}$-Amanitin

Acknowledgement

Supported by : National Research Foundation of Korea (NRF), Rural Development Administration

References

  1. Bellier, S., S. Chastant, P. Adenot, M. Vincent, J. P. Renard and O. Bensaude. 1997a. Nuclear translocation and carboxyl-terminal domain phosphorylation of RNA polymerase II delineate the two phases of zygotic gene activation in mammalian embryos. EMBO J. 16:6250-6262. https://doi.org/10.1093/emboj/16.20.6250
  2. Bellier, S., M. F. Dubois, E. Nishida, G. Almouzni and O. Bensaude. 1997b. Phosphorylation of the RNA polymerase II largest subunit during Xenopus laevis oocyte maturation. Mol. Cell. Biol. 17:1434-1440.
  3. Bregman, D. B., L. Du, S. van der Zee and S. L. Warren. 1995. Transcription-dependent redistribution of the large subunit of RNA polymerase II to discrete nuclear domains. J. Cell Biol. 129:287-298. https://doi.org/10.1083/jcb.129.2.287
  4. Egloff, S. and S. Murphy. 2008. Cracking the RNA polymerase II CTD code. Trends Genet. 24:280-288. https://doi.org/10.1016/j.tig.2008.03.008
  5. Jarrell, V. L., B. N. Day and R. S. Prather. 1991. The transition from maternal to zygotic control of development occurs during the 4-cell stage in the domestic pig, Sus scrofa: quantitative and qualitative aspects of protein synthesis. Biol. Reprod. 44:62-68. https://doi.org/10.1095/biolreprod44.1.62
  6. Lamond, A. I. and D. L. Spector. 2003. Nuclear speckles: a model for nuclear organelles. Nat. Rev. Mol. Cell Biol. 4:605-612. https://doi.org/10.1038/nrm1172
  7. Latham, K. E. 1999. Mechanisms and control of embryonic genome activation in mammalian embryos. Int. Rev. Cytol. 193:71-124. https://doi.org/10.1016/S0074-7696(08)61779-9
  8. Magnani, L. and R. A. Cabot. 2009. Manipulation of SMARCA2 and SMARCA4 transcript levels in porcine embryos differentially alters development and expression of SMARCA1, SOX2, NANOG, and EIF1. Reproduction 137:23-33. https://doi.org/10.1530/REP-08-0335
  9. Minami, N., T. Suzuki and S. Tsukamoto. 2007. Zygotic gene activation and maternal factors in mammals. J. Reprod. Dev. 53:707-715. https://doi.org/10.1262/jrd.19029
  10. Nguyen, V. T., F. Giannoni, M. F. Dubois, S. J. Seo, M. Vigneron, C. Kedinger and O. Bensaude. 1996. In vivo degradation of RNA polymerase II largest subunit triggered by alpha-amanitin. Nucleic Acids Res. 24:2924-2929. https://doi.org/10.1093/nar/24.15.2924
  11. Palancade, B. and O. Bensaude. 2003. Investigating RNA polymerase II carboxyl-terminal domain (CTD) phosphorylation. Eur. J. Biochem. 270:3859-3870. https://doi.org/10.1046/j.1432-1033.2003.03794.x
  12. Phatnani, H. P. and A. L. Greenleaf. 2006. Phosphorylation and functions of the RNA polymerase II CTD. Genes Dev. 20:2922-2936. https://doi.org/10.1101/gad.1477006
  13. Prasanth, K. V., P. A. Sacco-Bubulya, S. G. Prasanth and D. L. Spector. 2003. Sequential entry of components of the gene expression machinery into daughter nuclei. Mol. Biol. Cell 14:1043-1057. https://doi.org/10.1091/mbc.E02-10-0669
  14. Prather, R. S., J. W. Ross, S. C. Isom and J. A. Green. 2009. Transcriptional, post-transcriptional and epigenetic control of porcine oocyte maturation and embryogenesis. Soc. Reprod. Fertil. 66:165-176.
  15. Schoenbeck, R. A., M. S. Peters, L. F. Rickords, T. T. Stumpf and R. S. Prather. 1992. Characterization of deoxyribonucleic acid synthesis and the transition from maternal to embryonic control in the 4-cell porcine embryo. Biol. Reprod. 47:1118-1125. https://doi.org/10.1095/biolreprod47.6.1118
  16. Schultz, R. M. 1993. Regulation of zygotic gene activation in the mouse. Bioessays15:531-538. https://doi.org/10.1002/bies.950150806
  17. Schultz, R. M. 2002. The molecular foundations of the maternal to zygotic transition in the preimplantation embryo. Hum. Reprod. Update 8:323-331. https://doi.org/10.1093/humupd/8.4.323
  18. Spector, D. L. and A. I. Lamond. 2011. Nuclear speckles. Cold Spring Harb. Perspect. Biol. 1:3.
  19. Telford, N. A., A. J. Watson and G. A. Schultz. 1990. Transition from maternal to embryonic control in early mammalian development: a comparison of several species. Mol. Reprod. Dev. 26:90-100. https://doi.org/10.1002/mrd.1080260113
  20. Xie, S. Q., S. Martin, P. V. Guillot, D. L. Bentley and A. Pombo. 2006. Splicing speckles are not reservoirs of RNA polymerase II, but contain an inactive form, phosphorylated on serine2 residues of the C-terminal domain. Mol. Biol. Cell 17:1723-1733. https://doi.org/10.1091/mbc.E05-08-0726