Read Casey C, Edwards Lannett, Schrick Neal, Rhinehart Justin D, Payton Rebecca R, Campagna Shawn R, Castro Hector F, Klabnik Jessica L, Horn Emma J, Moorey Sarah E
Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA.
Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA.
Metabolites. 2021 Sep 14;11(9):623. doi: 10.3390/metabo11090623.
Induced ovulation of small pre-ovulatory follicles reduced pregnancy rates, embryo survival, day seven embryo quality, and successful embryo cleavage in beef cows undergoing fixed-time artificial insemination. RNA-sequencing of oocytes and associated cumulus cells collected from pre-ovulatory follicles 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the pre-ovulatory gonadotropin surge suggested reduced capacity for glucose metabolism in cumulus cells of follicles ≤11.7 mm. We hypothesized that the follicular fluid metabolome influences metabolic capacity of the cumulus-oocyte complex and contributes to reduced embryo cleavage and quality grade observed following induced ovulation of small follicles. Therefore, we performed a study to determine the correlation between pre-ovulatory follicle diameter and follicular fluid metabolome profiles in lactating beef cows (Angus, = 130). We synchronized the development of a pre-ovulatory follicle and collected the follicular contents approximately 20 h after GnRH administration. We then performed ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) metabolomic studies on 43 follicular fluid samples and identified 38 metabolites within pre-ovulatory follicles of increasing size. We detected 18 metabolites with a significant, positive correlation to follicle diameter. Individual and pathway enrichment analysis of significantly correlated metabolites suggest that altered glucose and amino acid metabolism likely contribute to reduced developmental competence of oocytes when small pre-ovulatory follicles undergo induced ovulation.
诱导排卵前小卵泡会降低接受定时人工授精的肉牛的妊娠率、胚胎存活率、第7天的胚胎质量以及胚胎成功分裂率。在给予促性腺激素释放激素（GnRH）以诱导排卵前促性腺激素激增23小时后，对从排卵前卵泡收集的卵母细胞及相关卵丘细胞进行RNA测序，结果表明直径≤11.7毫米的卵泡的卵丘细胞中葡萄糖代谢能力降低。我们推测卵泡液代谢组会影响卵丘 - 卵母细胞复合体的代谢能力，并导致小卵泡诱导排卵后观察到的胚胎分裂减少和质量等级降低。因此，我们进行了一项研究，以确定泌乳肉牛（安格斯牛，n = 130）排卵前卵泡直径与卵泡液代谢组谱之间的相关性。我们同步排卵前卵泡的发育，并在给予GnRH后约20小时收集卵泡内容物。然后，我们对43个卵泡液样本进行了超高效液相色谱 - 高分辨率质谱（UHPLC - HRMS）代谢组学研究，并在大小不断增加的排卵前卵泡中鉴定出38种代谢物。我们检测到18种与卵泡直径呈显著正相关的代谢物。对显著相关代谢物的个体和通路富集分析表明，当排卵前小卵泡进行诱导排卵时，葡萄糖和氨基酸代谢的改变可能导致卵母细胞发育能力降低。
