DEVELOPMENT OF AN EMBRYO CRYOPRESERVATION PROGRAM IN LABORATORY ANIMALS

该计划的目标是促进NIH动物的管理 遗传资源(NIHAGR)的开发利用 冷冻保存基因的胚胎/配子收集和处理技术 材料和提高生殖潜力。NIHAGR保持着一个 一系列动物模型物种，在物种内部，有大量的 生物医学研究中使用的无价的基因类型。胚胎保存用途 冷冻介质中的一种低温保护剂，允许充分脱水 以保护冷冻过程中的卵裂球。在变暖和稀释之后 在冷冻保护剂中，胚胎被培养以评估体外发育。 将胚胎移植到受体雌性体内的监视器 发展，因此生物能力。冷藏库胚胎是 在需要重新派生之前一直保持。实验室的主要工作重点 努力的是研究和优化小鼠的冷藏库技术， 兔子和老鼠。一项主要的研究发现是胚胎的可冻性 有明显的混杂和受基因影响。这样的回应一直是 在检测了多只小鼠的基因后，其中大部分表现为 标准化胚胎冷冻保存的特定基因型别存活率 程序。辅助项目调查比较方面的 改善胚胎的长期保存，特别强调 胚胎冷冻、升温、冷冻保护剂及强化方法 稀释和转移。在兔子身上的努力集中在收集程序上 使用新开发的玻璃化冷冻技术保存胚胎 程序。恢复老鼠胚胎的初步尝试也已经开始。 也已经开始了体外受精卵子的初步尝试 以及冷冻保存的精子。这些技术将特别重要 用于从个体或基因类型中抢救有限的遗传物质 体内生育能力差。

The program objective is to facilitate the management of the NIH Animal Genetic Resource (NIHAGR) through development and utilization of embryo/gamete collection and handling techniques for cryobanking genetic material and improving reproductive potential. The NIHAGR maintains an array of animal model species and, within species, a vast number of invaluable genotypes used in biomedical research. Embryo preservation uses a cryoprotectant in the freezing medium which allows sufficient dehydration to protect the blastomeres during freezing. Following warming and dilution of the cryoprotectant, embryos are cultured to assess in vitro development. Transplantation of embryos into recipient females monitors in vivo development and thus biological competence. Cryobanked embryos are maintained until needed for rederivation. The primary focus of laboratory efforts is the study and optimization of cryobanking technology in mice, rabbits and rats. A major research finding is that embryo freezability is confounded and influenced markedly by genotype. Such responses have been examined in over 64 mouse genotypes, most of which display genotype-specific survival rates to standardized embryo freeze-warming procedures. Ancillary projects investigate the comparative aspects of improving long-term embryo storage with particular emphasis on cryoprotectants and enhancing methods for embryo freezing, warming, dilution and transfer. Efforts in the rabbit focus on collection procedures and preservation of embryos using a newly developed vitrification procedure. Initial attempts also have begun to recover rat embryos. Preliminary attempts also have been initiated to in vitro fertilize ova as well as cryopreserve sperm. These techniques will be especially important for salvaging limited genetic material from individuals or genotypes with poor in vivo fertility.