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），通过开发和利用 胚胎配子的收集和处理技术 材料和提高生殖潜力。 NIHAGR维护一个 一系列动物模型物种，在物种内， 生物医学研究中使用的宝贵基因型。 胚胎保存用途 冷冻介质中的冷冻保护剂，其允许充分脱水 在冷冻过程中保护卵裂球。 加热和稀释后 培养胚胎以评估体外发育。 胚胎移植到受体雌性体内监测 发展和生物能力。 冷冻库胚胎是 保持直到需要重新派生。 实验室的主要焦点 努力是研究和优化小鼠冷冻库技术， 兔子和老鼠 一个主要的研究发现是胚胎的冷冻能力是 混淆和基因型的影响显着。 这种反应一直是 在超过64种小鼠基因型中进行了检查，其中大多数显示基因型- 标准化胚胎冷冻-加温程序的特定存活率。 辅助项目调查改善长期- 术语胚胎储存，特别强调冷冻保护剂， 用于胚胎冷冻、加温、稀释和移植的增强方法。 在兔子的努力集中在收集程序和保存 胚胎使用新开发的玻璃化程序。 最初的尝试 也已经开始恢复大鼠胚胎。 初步尝试也有 开始冷冻精子 这些技术将特别 对于从个体中抢救有限的遗传物质很重要， 体内育性差的基因型。

The program objective is to facilitate the management of the NIH Animal Genetic Resource (NIHAGR) through development and utilization of embryolgamete 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 blastomere 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 cryopreserve sperm. These techniques will be especially important for salvaging limited genetic material from individuals or genotypes with poor in vivo fertility.