Wu Chongyang, Sirard Marc-André
Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle (CRDSI), Département des Sciences Animales, Faculté des Sciences de l'Agriculture et de l'Alimentation, Université Laval, Québec City, QC, Canada.
Front Genet. 2020 Oct 14;11:557846. doi: 10.3389/fgene.2020.557846. eCollection 2020.
The bovine represents an important agriculture species and dairy breeds have experienced intense genetic selection over the last decades. The selection of breeders focused initially on milk production, but now includes feed efficiency, health, and fertility, although these traits show lower heritability. The non-genetic paternal and maternal effects on the next generation represent a new research topic that is part of epigenetics. The evidence for embryo programming from both parents is increasing. Both oocytes and spermatozoa carry methylation marks, histones modifications, small RNAs, and chromatin state variations. These epigenetic modifications may remain active in the early zygote and influence the embryonic period and beyond. In this paper, we review parental non-genetic effects retained in gametes on early embryo development of dairy cows, with emphasis on parental age (around puberty), the metabolism of the mother at the time of conception and culture (IVC) conditions. In our recent findings, transcriptomic signatures and DNA methylation patterns of blastocysts and gametes originating from various parental and IVC conditions revealed surprisingly similar results. Embryos from all these experiments displayed a metabolic signature that could be described as an "economy" mode where protein synthesis is reduced, mitochondria are considered less functional. In the absence of any significant phenotype, these results indicated a possible similar adaptation of the embryo to younger parental age, post-partum metabolic status and IVC conditions mediated by epigenetic factors.
牛是一种重要的农业物种，在过去几十年里，奶牛品种经历了强烈的基因选择。育种者的选择最初集中在产奶量上，但现在包括饲料效率、健康和繁殖力，尽管这些性状的遗传力较低。亲代对下一代的非遗传父本和母本效应是表观遗传学的一个新研究课题。来自双亲的胚胎编程证据正在增加。卵母细胞和精子都携带甲基化标记、组蛋白修饰、小RNA和染色质状态变化。这些表观遗传修饰可能在早期受精卵中保持活跃，并影响胚胎期及以后。在本文中，我们综述了配子中保留的亲代非遗传效应对奶牛早期胚胎发育的影响，重点关注亲代年龄（接近青春期）、受孕时母亲的代谢以及培养（体外受精）条件。在我们最近的研究结果中，来自各种亲代和体外受精条件的囊胚和配子的转录组特征和DNA甲基化模式显示出惊人的相似结果。所有这些实验中的胚胎都表现出一种代谢特征，可以描述为一种“经济”模式，即蛋白质合成减少，线粒体功能降低。在没有任何显著表型的情况下，这些结果表明胚胎可能通过表观遗传因素对较年轻的亲代年龄、产后代谢状态和体外受精条件进行了类似的适应。
