OOCYTE CRYOPRESERVATION IN RARE BIOMEDICAL MODELS

候选人将接受培训，同时产生关于猫类卵母细胞冷冻生物学的学术知识。 由于许多稀有的猫基因繁殖力差，配子冷冻结合体外胚胎 受体雌性的生产和转移可以帮助繁殖和管理这些种群。 目标是：1)研究卵母细胞的膜生物物理特性；2)表征和缓解 两步冷冻造成的冷冻损伤；以及3)应用新开发的卵母细胞冷冻保存方案 到罕见的猫科动物生物医学模型，以协助种群管理。因为这个潜在的可能性 从濒临死亡的动物中拯救配子的技术，重点将放在未成熟的卵母细胞上。影响 低温保护剂暴露，直接冷却，在零下温度下保持，然后直接插入 将对液氮进行表征。评价指标包括生物物理膜性能， 细胞内冰的形成、细胞骨架、细胞膜的完整性以及与积云的相互作用 细胞，以及最终在体外和体内的发育能力。研究结果将应用于猫科动物模型。 同时利用对选定野生猫科动物物种的独特访问来更快地了解 机械装置。这种基本的和比较的方法提供了一个多学科的培训机会 这将使应聘者成为一名生理学家，拥有生物物理学、低温生物学和 卵母细胞的体外培养。研究的好处将是对生物物理性质的透彻了解 未成熟猫卵母细胞及其冷冻-冷冻-解冻存活能力调节因素的研究 发育成可存活的胚胎和后代。实际的好处将是另一个解决 管理少数繁殖能力低下的猫科动物一直是一项艰巨的任务。 与公共健康相关：动物模型对于研究与理解有关的机制是必不可少的 以及通过生物医学研究改善人类状况。这种多学科的方法将 提供新的卵母细胞冷冻方案，用于管理用作生物医学的猫克隆 人类疾病的模型。

The Candidate will receive training while producing scholarly knowledge about felid oocyte cryobiology. Since many rare cat genotypes reproduce poorly, gamete cryopreservation combined with in vitro embryo production and transfer in recipient females can help to reproduce and manage these populations. Objectives are to: 1) investigate membrane biophysical properties of the oocyte; 2) characterize and mitigate cryoinjuries caused by two-step freezing; and 3) apply a newly developed oocyte cryopreservation protocol to rare felid biomedical models to assist in population management. Because of the potential of this technology for 'rescuing' gametes from dying animals, the focus will be on the immature oocyte. Impact of cryoprotectant exposure, direct cooling and holding at a subzero temperature followed by direct plunging into liquid nitrogen will be characterized. Evaluation targets include biophysical membrane properties, intracellular ice formation, integrity of the cytoskeleton, cytoplasmic membrane and interactions with cumulus cells, and eventually developmental competence in vitro and in vivo. Findings will be applied to felid models while taking advantage of unique access to selected wild felid species to more rapidly understand mechanisms. This fundamental and comparative approach provides a multidisciplinary training opportunity that will allow the Candidate to advance as a physiologist with expertise in biophysics, cryobiology and in vitro culture of oocytes. The research benefit will be a thorough understanding of the biophysical properties of the immature cat oocyte and the factors regulating its ability to survive cooling-freezing-thawing and to develop into a viable embryo and offspring. The practical benefit will be another tool for addressing the always difficult task of managing small populations of reproductively compromised felids. Relevance to public health: Animal models are essential to studying mechanisms pertinent to understanding and improving the human condition through biomedical research. This multidisciplinary approach will provide new oocyte cryopreservation protocols useful to the management of cat colonies used as biomedical models for human diseases.