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: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=451707
• 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.

继续积极和成功的研究计划，以确定特征和调节生殖现象称为专性胚胎滞育（又名延迟着床）提出。哺乳动物胚胎在囊胚期发育停止时发生滞育，随后被重新激活并植入以继续妊娠。这是一种进化策略，使交配从妊娠期分开，使分娩在最佳的生存季节。滞育是包括黄鼬、熊和海豹在内的几个食肉动物家族的妊娠程序。从春季繁殖的食肉动物的几个星期到秋季交配的物种的几个月。这一假说是基于胚胎滞育是由子宫分泌的因子调控的，而胚胎着床是由激活的胚胎发起和安排的。总体目标是确定胚胎滞育中发育停止的细胞机制，并探索胚胎-子宫对话，使胚胎重新激活并诱导着床进入子宫。所采用的模型是农场的水貂。第一个具体目标是利用我们最近的基因发现调查的结果来确定子宫和胚胎调节胚胎进入和退出滞育的机制。通过检测细胞信号和细胞周期调控基因的表达，在体外收集胚胎并记录其进入滞育，在体内收集胚胎并记录其退出滞育。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将被测试。第二个具体目标是研究滋养细胞作为局部着床过程和子宫内膜侵袭的调节因子。它将通过检查侵入性成分，合胞滋养细胞的形成和调节以及对子宫重塑的形态和基因表达事件的研究来解决。这些新的实验和方法将为了解其他哺乳动物的滞育和着床提供新的见解，并为了解胎盘形成和胚胎丢失提供重要的信息。