OOCYTE CRYOPRESERVATION IN RARE BIOMEDICAL MODELS

候选人将接受培训，同时产生有关猫科动物卵母细胞冷冻生物学的学术知识。 由于许多稀有猫基因型繁殖能力差， 受体雌性的生产和转移有助于繁殖和管理这些种群。 目的是：1）研究卵母细胞的膜生物物理特性; 2）表征和减轻 两步冷冻引起的冷冻损伤; 3）应用新开发的卵母细胞冷冻保存方案 稀有猫科动物的生物医学模型，以协助人口管理。因为这个项目的潜力 在这项从垂死动物体内“拯救”配子的技术中，重点将放在未成熟的卵母细胞上。影响 冷冻保护剂暴露，直接冷却并保持在零度以下的温度，然后直接浸入 液氮将被表征。评价目标包括生物物理膜性能， 细胞内冰的形成，细胞骨架的完整性，细胞质膜和与卵丘的相互作用 细胞，并最终在体外和体内发育能力。研究结果将应用于猫科动物模型 同时利用对选定的野生猫科动物物种的独特访问， 机制等这种基本的比较方法提供了一个多学科的培训机会 这将使候选人能够作为一名具有生物物理学，低温生物学和生物医学专业知识的生理学家前进。 卵母细胞的体外培养。研究的好处将是对生物物理特性的透彻理解 猫未成熟卵母细胞的冷冻-解冻能力及其影响因素 发育成可存活的胚胎和后代。实际利益将是解决这一问题的另一个工具。 管理繁殖能力低下的小种群总是一项艰巨的任务。 与公共卫生的相关性：动物模型对于研究与理解有关的机制至关重要 并通过生物医学研究改善人类状况。这一多学科方法将 提供了新的卵母细胞冷冻保存方案，可用于管理用作生物医学的猫群， 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.