Developing markers for predicting bovine embryonic health and viability

全球牛群的早期胚胎死亡（EEM）成本每年约为1.28万亿美元。关于为什么有些胚胎会发育，有些胚胎会“变慢”并最终停止发育的信息很少。引入精细的生物技术，如代谢组学和单胚胎水平的基因表达研究，可以提供新的见解。我们利用代谢组学和基因阵列技术对慢速和快速生长的胚胎进行了初步研究，发现它们的能量通路存在明显差异。因此，我们假设胚胎代谢的改变导致了观察到的胚胎发育潜力的差异，并且代谢组学方法应用于从高发育潜力和低发育潜力胚胎收集的废培养基将定义其代谢途径的差异。我们建议：1)鉴定单胚胎、慢胚胎和快速胚胎的代谢组学特征；2)阐明慢胚胎和快速胚胎之间代谢特征差异的分子机制；3)在体外培养中使用代谢抑制剂和增强剂验证推定的代谢产物标记。该研究将涉及使用单个胚胎进行体外培养，使用600 MHz质子核磁共振定时培养基进行代谢组学评估，基因表达研究，线粒体健康评估，ATP分析，siRNA基因抑制或使用化学代谢抑制剂或增强剂。据我们所知，这项研究将是第一个将能量途径基因与胚胎植入前哺乳动物的代谢组学特征联系起来的研究。从这项研究中获得的信息有望更好地了解哺乳动物着床前的发育阶段，并有望开发胚胎评估标记，作为提高牲畜生产的工具。加拿大养牛业每年产生超过386亿美元的收入，通过这些生殖生物技术工具提高养牛系统的效率将对养牛业产生重大的经济效益。

Global cost of Early embryonic mortality (EEM) in total cattle population accrues to about $ 1.28 trillion annually. There exists very little information on why some embryos develop and some "slow down" and eventually arrest. Introduction of refined biological techniques like metabolomics and gene expression studies at the level of single embryos can provide new insights. Our preliminary studies using metabolomics and gene array technologies on slow and fast growing embryos has revealed distinct differences in their energy pathways. Therefore, we hypothesize that altered embryonic metabolism causes the differences in observed embryonic developmental potential and that metabolomics approach applied to spent media collected from high and low developmental potential embryos will define variations in their metabolism pathways. We propose to 1) Characterize the metabolomic signatures of single, slow and fast growing bovine embryos, 2) Elucidate the molecular mechanism for the differential metabolic profiles between slow and fast cleaving embryos, 3) Validate putative metabolite markers using metabolic inhibitors and enhancers during in vitro culture. The study would involve the use of single embryos for in vitro culture, timed media aspirations for metabolomic assessment using 600 MHz proton NMR, gene expression studies, mitochondrial health assessment, ATP assays, siRNA gene inhibition or use of chemical metabolic inhibitors or enhancers. To our knowledge, this study will be the first of its kind to link energy pathway genes and metabolomic profile of preimplantation mammalian embryos. Information derived from this study is anticipated to provide a better understanding of the preimplantation period of development in mammals and also holds the promise to evolving markers for embryo assessment as a tool to enhancing livestock production. Canadian cattle industry generates over $ 38.6 billion annually and improvement in the efficiency of cattle production system through these tools of reproductive biotechnology will have significant economic benefits to the cattle industry.