Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, 53115 Bonn, Germany.
Anim Reprod Sci. 2012 Sep;134(1-2):76-83. doi: 10.1016/j.anireprosci.2012.08.014. Epub 2012 Aug 11.
Early embryonic development, the period from maturation until blastocyst formation, is one of the most critical periods of mammalian development involves various morphological, cellular, and biochemical changes related to genomic activity. During the post-fertilization period, several major developmental events occur in the embryo which are regulating by a harmonized expression of genes and strongly influenced by culture conditions. The products of these genes are involved in various biological processes including metabolism, growth factor/cytokine signaling, stress adaptation, transcription and translation, epigenetic regulation of transcription, apoptosis, compaction and blastocyst formation. Post-fertilization culture environment is known to be the most important factor determining the quality of the resulting embryos as indicated in terms of cryo-tolerance and relative abundance of transcripts. However, the exact effect of culture conditions on gene expression and subsequent influences on molecular pathways controlling early development is still unknown. A number of culture environmental factors can influence the gene expression of produced embryos such as media composition, serum supplementation, number of embryos present in the culture drop and gas atmosphere. During the last ten years several studies were concerned with differences in the transcriptome profile of embryos produced under different environmental conditions and its subsequent influence on embryo developmental competence. From these studies, several genes have been determined as candidate genes controlling preimplantation embryo development and affecting its quality. Here we will discuss results of different experiments investigated the effect of different culture conditions on the transcriptome profile of bovine blastocyst. These experiments identified molecular mechanisms and pathways that influenced by culture conditions and this will enable to launch strategies to modify culture conditions to enhance the development of competent blastocyst.
早期胚胎发育是哺乳动物发育过程中最关键的时期之一，涵盖了从成熟到囊胚形成的阶段，涉及与基因组活性相关的各种形态、细胞和生化变化。在受精后时期，胚胎中发生了几个主要的发育事件，这些事件受到基因协调表达的调控，并受到培养条件的强烈影响。这些基因的产物参与了各种生物学过程，包括代谢、生长因子/细胞因子信号转导、应激适应、转录和翻译、转录的表观遗传调控、细胞凋亡、致密化和囊胚形成。已知受精后培养环境是决定胚胎质量的最重要因素，这表现在胚胎的耐冷冻性和转录本的相对丰度上。然而，培养条件对基因表达的具体影响以及对控制早期发育的分子途径的后续影响仍然未知。许多培养环境因素可以影响产生胚胎的基因表达，如培养基组成、血清补充、培养滴中胚胎的数量和气体氛围。在过去的十年中，有几项研究关注了不同环境条件下产生的胚胎的转录组谱差异及其对胚胎发育能力的后续影响。从这些研究中，确定了几个候选基因来控制胚胎的植入前发育，并影响其质量。在这里，我们将讨论不同实验的结果，这些实验研究了不同培养条件对牛囊胚转录组谱的影响。这些实验确定了受培养条件影响的分子机制和途径，这将使我们能够制定策略来改变培养条件，以提高有能力的囊胚的发育。
