Unravelling molecular signatures of oocyte developmental competence in cattle

揭示牛卵母细胞发育能力的分子特征

• 批准号: 2753060
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2753060
• 关键词: Unravelling; molecular; signatures; oocyte; developmental

Sustainable cattle production is critical to feed an increasing world population under projected food shortages due to climate change, and to alleviate methane emissions. Reproductive biotechnologies such as in vitro embryo production (IVEP) coupled with embryo transfer (ET) can increase the number of offspring from a single high genetic merit cow, contributing substantially to enhancing global food security, vastly decreasing the number of cows involved in cattle production systems, which in turn will reduce the carbon footprint of the cattle industry.However, to achieve wider commercial acceptance, the efficiency of IVEP needs to be improved as only 15-40 % of oocytes used in IVEP manage to achieve an embryonic stage ready for ET. Aneuploidies (abnormal chromosome numbers) in fertilised eggs are overwhelmingly due to errors in female meiosis, and contribute significantly to implantation failure, spontaneous miscarriage and stillbirth. Studies in mice have highlighted the role of key proteins responsible for the prevention of aneuploidies in oocytes and other cell division errors that would ordinarily result in embryonic demise. Yet, there is a substantial knowledge gap in bovine oocytes in this regard. Hence, this project aims to elucidate the role of candidate proteins highly likely to provide a readout of oocyte developmental competence in cattle.The project will utilise state-of-the-art live cell imaging where fluorescent transgenes will be microinjected into bovine oocytes to allow real time monitoring of proteins of interest, followed by analysis of known indicators of prognosis (e.g. spindle morphology and chromosome alignment to indicate genomic stability). Transgenic oocytes will also be fertilised and allowed to develop to the blastocyst stage (i.e. around 150 cells, a common embryonic stage used for ET) where several cellular and molecular endpoints associated embryo viability will be analysed (e.g. cell number and epigenetic markers such as H3K27me3). Importantly, no offspring will be produced (i.e. no ET will be performed) and abattoir-derived ovaries will be used to extract oocytes for the experiments (a by-product from the cattle industry), hence no animals will be culled for the sake of the project.The project will provide the foundations to identify biomarkers of bovine oocyte developmental competence with the long-term aim of improving the efficient application of commercial bovine IVEP. Furthermore, given the similarities in oocyte and early embryo physiology between humans and cattle, this bovine model will provide data of relevance for human reproductive medicine.

在气候变化导致的预计粮食短缺的情况下，可持续的养牛生产对于养活不断增长的世界人口和减少甲烷排放至关重要。生殖生物技术，如体外胚胎生产（IVEP）与胚胎移植（ET）相结合，可以增加单个高遗传价值奶牛的后代数量，极大地促进了全球粮食安全，大大减少了牛生产系统中奶牛的数量，从而减少了养牛业的碳足迹。然而，为了获得更广泛的商业接受，IVEP的效率需要提高，因为只有15- 40%用于IVEP的卵母细胞能够达到胚胎阶段，为ET做好准备。受精卵的非整倍体（染色体数目异常）绝大多数是由于女性减数分裂错误造成的，这在很大程度上导致了着床失败、自然流产和死胎。在小鼠身上的研究强调了关键蛋白质的作用，这些蛋白质负责预防卵母细胞中的非整倍体和其他通常会导致胚胎死亡的细胞分裂错误。然而，在牛卵母细胞在这方面有一个实质性的知识差距。因此，本项目旨在阐明候选蛋白的作用，这些候选蛋白极有可能提供牛卵母细胞发育能力的读数。该项目将利用最先进的活细胞成像技术，将荧光转基因微注射到牛卵母细胞中，以便实时监测感兴趣的蛋白质，然后分析已知的预后指标（例如纺锤体形态和染色体排列，以指示基因组稳定性）。转基因卵母细胞也将受精并允许发育到囊胚阶段（即大约150个细胞，用于ET的常见胚胎阶段），届时将分析与胚胎活力相关的几个细胞和分子终点（例如细胞数量和表观遗传标记，如H3K27me3）。重要的是，不会产生后代（即不会进行ET），并且屠宰场衍生的卵巢将用于提取用于实验的卵母细胞（养牛业的副产品），因此不会为了该项目而宰杀动物。该项目将为鉴定牛卵母细胞发育能力的生物标志物提供基础，并为提高商品牛卵母细胞发育能力的有效应用提供长期目标。此外，鉴于人类和牛在卵母细胞和早期胚胎生理上的相似性，该牛模型将为人类生殖医学提供相关数据。