Epigenetics in preimplantation mammalian development

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• 作者：Sebastian Canovas^a ; ¹ ; ^{scber@um.es" class="auth_mail" title="E-mail the corresponding author} ; Pablo Juan Ross^b ; ^{pross@ucdavis.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：DNA methylation ; Histone modifications ; Embryo ; Imprinting ; Reprogramming ; Pronucleus
• 刊名：Theriogenology
• 出版年：2016
• 出版时间：1 July 2016
• 年：2016
• 卷：86
• 期：1
• 页码：69-79
• 全文大小：1113 K

文摘

Fertilization is a very dynamic period of comprehensive chromatin remodeling, from which two specialized cells result in a totipotent zygote. The formation of a totipotent cell requires extensive epigenetic remodeling that, although independent of modifications in the DNA sequence, still entails a profound cell-fate change, supported by transcriptional profile modifications. As a result of finely tuned interactions between numerous mechanisms, the goal of fertilization is to form a full healthy new individual. To avoid the persistence of alterations in epigenetic marks, the epigenetic information contained in each gamete is reset during early embryogenesis. Covalent modification of DNA by methylation, as well as posttranslational modifications of histone proteins and noncoding RNAs, appears to be the main epigenetic mechanisms that control gene expression. These allow different cells in an organism to express different transcription profiles, despite each cell containing the same DNA sequence. In the context of replacement of spermatic protamine with histones from the oocyte, active cell division, and specification of different lineages, active and passive mechanisms of epigenetic remodeling have been revealed as critical for editing the epigenetic profile of the early embryo. Importantly, redundant factors and mechanisms are likely in place, and only a few have been reported as critical for fertilization or embryo survival by the use of knockout models. The aim of this review is to highlight the main mechanisms of epigenetic remodeling that ensue after fertilization in mammals.