Exogenous expression of OCT4 facilitates oocyte‐mediated reprogramming in cloned porcine embryos. Issue 9 (18th August 2014)

• Record Type: Journal Article
• Authors: Ji, Qianqian; Cong, Peiqing; Zhao, Haijing; Song, Zhenwei; Zhao, Guangyin; Gao, Jintao; Nie, Yu; Chen, Yaosheng
• Is Part Of: Molecular reproduction and development. Volume 81:Issue 9(2014:Sep.)
• Page Start: 820
• Page End: 832
• Publication Date: 2014-08-18
• Subjects: Reproduction -- Periodicals; Molecular biology -- Periodicals; Molecular genetics -- Periodicals; Embryology -- Periodicals; 571.8
• DOI: 10.1002/mrd.22351
• Languages: English
• ISSNs: 1040-452X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>SUMMARY</title> <sec id="mrd22351-sec-0001" sec-type="section"> <p>OCT4 is a well‐established regulator of pluripotency and nuclear reprogramming. To determine if improving OCT4 abundance can facilitate oocyte‐mediated reprogramming in cloned porcine embryos, we artificially increased OCT4 levels by co‐incubating donor cells with 50 ng/µl <italic>OCT4</italic> plasmid. We observed higher rates of blastocyst formation (<italic>P</italic> < 0.05) and lower levels of blastocyst apoptosis in nuclear‐transfer‐derived embryos carrying <italic>OCT4</italic>‐incubated donor nuclei (<italic>OCT4</italic>‐SCNT). The beneficial effect caused by exogenous expression of <italic>OCT4</italic> involves epigenetic changes, wherein increased histone acetylation (AcH3K9) appeared in <italic>OCT4</italic>‐SCNT embryos at the one‐cell and blastocyst stages and reduced histone methylation (H3K9me2) was observed at the one‐cell stage (<italic>P</italic> < 0.05). There was a transient increase in exogenous <italic>OCT4</italic> and an up‐regulation of endogenous <italic>OCT4</italic> level in <italic>OCT4</italic>‐SCNT embryos (<italic>P</italic> < 0.05), while the expression pattern of epigenetic enzymes was changed. These modifications were accompanied by an up‐regulation of <italic>CDX2</italic>, whose interaction with <italic>OCT4</italic> is instrumental for implantation, and a down‐regulation of <italic>XIST</italic>, a negative indicator of reprogramming (<italic>P</italic> < 0.05). Taken together, our results support a role for exogenous expression of <italic>OCT4</italic> in improving the efficiency of nuclear reprogramming while establishing a convenient and timesaving method to improve nuclear‐transfer outcomes. <italic>Mol. Reprod. Dev. 81: 820–832, 2014. © 2014 Wiley Periodicals, Inc</italic>.</p> </sec> </abstract>