Impact of Endometrial Lipids on Uterine Histotroph Composition and Preimplantation Conceptus Development in Dairy Cattle

子宫内膜脂质对奶牛子宫组织营养成分及着床前胚胎发育的影响

• 批准号: RGPIN-2017-05198
• 负责人: DeSouzaRibeiro, Eduardo
• 金额: $ 1.89万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=648862
• 关键词: Impact; Endometrial; Lipids; Uterine; Histotroph

Reproduction is a critical component of dairy sustainability because it impacts the overall milk yield in a herd and its' production efficiency. Pregnancy loss in lactating cows, however, is substantial and impairs reproductive efficiency and profitability of dairy farms. Elongation of the preimplantation conceptus (embryo and associated extra-embryonic membranes) is a prerequisite for successful pregnancy in cattle and depends on histotroph secretion by the endometrium. Nonetheless, approximately one third of viable blastocysts fail to elongate and survive by the end of the fourth week of development. Improvements in reproductive efficiency of dairy cows will require the development of strategies to minimize early embryonic mortality, which in turn will require a better elucidation of critical events in early developmental biology. ****** Recently, our research group investigated the metabolome of uterine histotroph and the transcriptome of conceptus cells during the process of elongation. Our results demonstrated that the histotroph is rich in lipids, and suggest that significant changes in gene expression of conceptus cells are likely coordinated by lipids through activation of transcription factors and cell signaling. The bovine endometrium accumulates lipids from the time of fertilization of the oocyte to the onset of conceptus elongation 14 days later, and likely provides the main source of lipids for the developing conceptus. However, detailed information on lipid composition in the endometrium and its importance for histotroph composition and conceptus development are unavailable.****** The long-term goals of the proposed research program are to understand the importance of endometrial lipids for preimplantation conceptus development and survival in lactating dairy cows, and to develop nutraceutical strategies to reduce pregnancy losses and improve reproductive efficiency of dairy herds. The specific objectives of this research program are 1) to investigate how and what lipids are accumulated in the bovine endometrium by the time of initiation of conceptus elongation; 2) to investigate how and what lipids are transferred from the endometrium to the developing conceptus during the elongation phase; 3) to evaluate the impact of specific lipids on the biology of conceptus cells; and 4) to develop a nutraceutical supplement capable of enriching the endometrium of lactating cows with target lipids that would favor conceptus development and survival.

繁殖是乳制品可持续发展的关键组成部分，因为它影响牛群的整体产奶量及其生产效率。然而，哺乳期奶牛的妊娠损失是巨大的，并且损害了奶牛场的繁殖效率和盈利能力。着床前概念（胚胎和相关的胚胎外膜）的伸长是牛成功妊娠的先决条件，并且取决于子宫内膜的组织营养物质分泌。尽管如此，大约三分之一的存活囊胚在发育第四周结束时未能伸长并存活。奶牛繁殖效率的提高需要制定尽量减少早期胚胎死亡率的策略，这反过来又需要更好地阐明早期发育生物学中的关键事件。 ****** 最近，我们课题组对子宫伸长过程中子宫组织营养物质的代谢组和孕体细胞的转录组进行了研究。我们的结果表明，组织营养细胞富含脂质，并表明孕体细胞基因表达的显着变化可能是通过转录因子和细胞信号传导的激活由脂质协调的。牛子宫内膜从卵母细胞受精到14天后概念伸长开始期间积累脂质，并且可能为发育中的概念提供脂质的主要来源。然而，关于子宫内膜脂质成分及其对组织营养成分和受孕发育的重要性的详细信息尚不清楚。****** 拟议研究计划的长期目标是了解子宫内膜脂质对泌乳奶牛着床前受孕发育和存活的重要性，并制定营养策略以减少妊娠损失并提高奶牛的繁殖效率 牛群。该研究计划的具体目标是 1) 研究在受孕开始伸长时牛子宫内膜中如何积累脂质以及积累哪些脂质； 2) 研究在伸长阶段脂质如何以及什么从子宫内膜转移到发育中的概念； 3）评估特定脂质对孕体细胞生物学的影响； 4) 开发一种营养补充剂，能够使泌乳牛的子宫内膜富含有利于胎儿发育和存活的目标脂质。