Delayed implantation and seasonal breeding

延迟着床和季节性繁殖

• 批准号: 137013-2008
• 负责人: Murphy, Bruce
• 金额: $ 5.54万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=513727
• 关键词: Delayed; implantation; seasonal; breeding

Continuation of an active and successful research program to determine characteristics and regulation of a reproductive phenomenon known as obligate embryonic diapause (aka delayed implantation) is proposed. Diapause occurs when mammalian embryos undergo developmental arrest at the blastocyst stage, to be later reactivated and implanted for continuation of pregnancy. It is an evolutionary strategy that uncouples mating from gestation, allowing parturition at the optimal season for survival. Diapause is in the gestational program of several carnivore families including the weasels, bears and seals. It persists from a few weeks in spring breeding carnivores to several months in species that mate in the fall. The proposal is based on the hypothesis that embryonic diapause is regulated by factors secreted by the uterus, while embryo implantation is initiated and orchestrated by the activated embryo. The overall objective is to determine the cellular mechanisms of the developmental arrest in embryonic diapause and to explore the embryo-uterine dialog that reactivates the embryo and induces implantation into the uterus. The model employed is the ranch mink. The first specific objective is to exploit results of our recent gene discovery investigation to determine mechanisms by which the uterus and embryo regulate entry and exit of the embryo from diapause. Embryos will be collected at the morula stage and entry into diapause chronicled in vitro, as will exit from diapause in embryos collected in vivo, by probing for expression of cell signaling and cell cycle regulatory genes. The pattern of expression of factors secreted by the uterus and their capacity to reactivate embryos in vitro will be tested. The second specific objective is to investigate trophoblast as a regulator of local processes of implantation, and endometrial invasion. It will be addressed by examination of formation and regulation of the invasive component, the syncytial trophoblast and by investigation of morphological and gene expression events of uterine remodeling. New insight into diapause and implantation and information significant to understanding placental formation and embryo loss in other mammals will be gained from these novel experiments and approaches.

建议继续进行一项积极而成功的研究计划，以确定被称为专性胚胎滞育（又名延迟着床）的生殖现象的特征和调节。 当哺乳动物胚胎在胚泡阶段经历发育停滞时，滞育发生，随后被重新激活并植入以继续妊娠。 这是一种进化策略，将交配与妊娠分开，允许在最佳生存季节分娩。 滞育是包括黄鼠狼、熊和海豹在内的几种食肉动物的妊娠期。 从春季繁殖的食肉动物持续几周到秋季交配的物种持续几个月。 该建议基于这样的假设，即胚胎滞育是由子宫分泌的因子调节的，而胚胎植入是由激活的胚胎启动和协调的。总体目标是确定胚胎滞育中发育停滞的细胞机制，并探索重新激活胚胎并诱导植入子宫的胚胎-子宫对话。 采用的模型是牧场水貂。 第一个具体的目标是利用我们最近的基因发现调查的结果，以确定子宫和胚胎调节进入和退出滞育的胚胎的机制。 将在桑椹胚阶段收集胚胎，并通过探测细胞信号传导和细胞周期调控基因的表达，在体外记录进入滞育，以及在体内收集的胚胎中从滞育中退出。 将检测子宫分泌因子的表达模式及其在体外重新激活胚胎的能力。 第二个具体的目标是研究滋养层作为一个调节器的局部过程中的植入，子宫内膜的侵袭。 它将通过检查的形成和调节的侵入性成分，合胞滋养层和子宫重塑的形态和基因表达事件的调查。 从这些新的实验和方法中，将获得对滞育和着床的新的认识，以及对理解其他哺乳动物的胎盘形成和胚胎丢失具有重要意义的信息。