The expression patterns of DNA methylation reprogramming related genes are associated with the developmental competence of cloned embryos after zygotic genome activation in pigs
The expression patterns of DNA methylation reprogramming related genes are associated with the developmental competence of cloned embryos after zygotic genome activation in pigs
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DNA甲基化重编程相关基因的表达模式与猪合子基因组激活后克隆胚胎的发育能力相关
DOI：
10.1016/j.gep.2015.04.001
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发表时间：
2015-05-01
影响因子：
1.2
通讯作者：
He, Hongbin
中科院分区：
文献类型：
--
作者：
Huan, Yanjun;Wang, Hongmei;He, Hongbin
DNA甲基化重编程是由DNA甲基化和去甲基化相关基因调控的，对早期胚胎发育至关重要；然而，在克隆胚胎中，它是不完整的，导致克隆效率不高。先前的研究表明，DNA甲基化抑制剂5-aza-2′-脱氧胞苷（5-aza-dC）能够促进克隆胚胎的发育，因此，调控DNA甲基化重编程的基因应该在克隆胚胎中适当表达。为了研究胚胎发育与DNA甲基化重编程相关基因的表达模式是否存在相关性，我们研究了含有DNA甲基转移酶（Dnmt1和Dnmt3a）、10 - 11易位（Tet）双加氧酶（Tet1、Tet2和Tet3）和碱基切除修复相关基因(包括活化诱导脱氨（Aid）、猪早期胚胎胸腺嘧啶DNA糖基化酶（Tdg）和AP内切酶1 （Apex1）。在本研究中，我们的研究结果表明，与体外受精胚胎相比，克隆胚胎在4细胞期后发育延迟和减少，DNA甲基化重编程相关基因转录下调，8细胞期、桑胚期和囊胚期的胚胎比例显著（P < 0.05）降低（72 h时分别为19.69%对32.64%，120 h时分别为16.67%对25.49%，156 h时分别为19.82%对26.29%），Dnmt3a转录水平显著降低（P < 0.05）。Tet1, Tet2, Tet3, Aid， Tdg和Apex1。克隆胚胎经5-aza-dC处理后，其发育进程和DNA甲基化重编程相关基因的转录水平得到改善，与受精卵中检测到的更为相似。此外，我们发现5-aza-dC处理后的猪克隆胚胎中合子基因组激活和囊胚质量相关基因的转录也得到了有效的促进。综上所述，我们的研究结果表明，在猪克隆胚胎中存在DNA甲基化重编程相关基因的转录紊乱，而5-aza-dC诱导的猪克隆胚胎在4细胞期后的发育增强伴随着DNA甲基化重编程相关基因的表达提高。说明DNA甲基化重编程相关基因的表达模式与受精卵基因组激活后的猪克隆胚胎发育能力呈正相关。(C) 2015 Elsevier B.V.版权所有
DNA methylation reprogramming, regulated by DNA methylation and demethylation related genes, is essential for early embryo development; however, it is incomplete in cloned embryos, leading to poor cloning efficiency. Previous studies have shown that DNA methylation inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC), could enhance the development of cloned embryos, thus, the genes regulating DNA methylation reprogramming should appropriately express in these embryos. To examine whether there is a correlation between embryo development and the expression patterns of DNA methylation reprogramming related genes, we investigated the developmental progress and transcription levels of candidate genes containing DNA methyltransferases (Dnmt1 and Dnmt3a), ten eleven translocation (Tet) dioxygenases (Tet1, Tet2 and Tet3) and base excision repair related genes including activation induced deamination (Aid), thymine DNA glycosylase (Tdg) and AP endonuclease 1 (Apex1) in porcine early embryos. In this study, our results demonstrated that compared with in vitro fertilized embryos, delayed and reduced development and downregulated transcripts of DNA methylation reprogramming related genes after the 4-cell stage were observed in cloned embryos, showing the significantly (P < 0.05) lower proportions of embryos at the 8-cell, morula and blastocyst stages (19.69% vs 32.64% at 72 h, 16.67% vs 25.49% at 120 h and 19.82% vs 26.29% at 156 h, respectively) and transcription levels of Dnmt3a, Tet1, Tet2, Tet3, Aid, Tdg and Apex1. When cloned embryos were treated with 5-aza-dC, the developmental progress and transcription levels of DNA methylation reprogramming related genes were improved, more similar to those detected in fertilized counterparts. Furthermore, we found that the transcripts of zygotic genome activation and blastocyst quality related genes were also effectively promoted in porcine cloned embryos after 5-aza-dC treatment. In conclusion, our results demonstrated that the disturbed transcripts of DNA methylation reprogramming related genes were observed in porcine cloned embryos, while the enhanced development of porcine cloned embryos induced by 5-aza-dC was accompanied with the improved expression of DNA methylation reprogramming related genes after the 4-cell stage, providing a positive correlation between the expression patterns of DNA methylation reprogramming related genes and the developmental competence of porcine cloned embryos after zygotic genome activation. (C) 2015 Elsevier B.V. All rights reserved.