Development of an Economic Process to Store and Recover Homozygous Mouse Strains

描述（由申请人提供）：实验室小鼠是研究人类疾病的关键模型，主要是因为小鼠和人类基因组惊人相似。通过破坏基因或插入人类基因来修改小鼠基因组的能力使研究人员能够开发出高度特异性的菌株进行研究，并导致菌株数量和复杂性呈指数级增长。创建这些菌株并不简单，复杂的菌株必须通过繁殖密切相关的动物来保持纯合;否则，非连锁基因座将在后代中分离，菌株特征将被破坏。冷冻保存用于储存未被积极研究的菌株，并在繁殖菌落丢失时保护菌株。然而，在冷冻保存或恢复期间，使用野生型卵子供体，并且不能保持菌株的纯合性。此外，可用的冷冻保存和储存菌株的方法是昂贵的，耗时的，并且需要许多动物。迫切需要开发一种以保留原始基因型的方式冷冻保存菌株的方法。该方法必须快速，经济，使用很少的动物。将开发常规和新型辅助生殖技术的组合，以存档和恢复纯合菌株。与目前的胚胎冷冻保存方法相比，这些方法将使用3-5倍的资源。将通过冷冻保存精子和卵巢来存档纯合菌株。然后使用手术人工授精（手术AI）和卵巢移植的组合重建菌株。此外，将探索连续卵巢移植和手术取卵方法作为恢复冷冻保存精子和卵巢的替代方法。将开发从冷冻机中重构菌株以反映科学界的不同需求，并将提供：i）快速和低成本回收，提供2-3个纯合育种对，和ii）适度快速，较高的成本回收，提供=10个纯合育种对。 公共卫生相关性（由申请人提供）：辅助生殖技术现在占第一世界国家所有出生人数的5%以上。人类IVF的一个主要限制是卵母细胞的缺乏。我们的研究将有助于了解并有望提高人类卵母细胞的生产力。

DESCRIPTION (provided by applicant): The laboratory mouse is a key model for the study of human diseases mainly because the mouse and human genomes are strikingly similar. The ability to modify the mouse genome by disrupting genes or inserting human genes allows researchers to develop highly specific strains for study and has led to an exponential growth in the number and complexity of strains. Creating these strains is not trivial and complex strains must be kept homozygous through breeding closely related animals; otherwise, non-linked loci will segregate among the offspring and strain characteristics will be disrupted. Cryopreservation is used to store strains that are not actively being studied and to protect strains if the breeding colony is lost. However, during cryopreservation or recovery wild type egg donors are used and the homozygosity of the strain is not maintained. In addition, the available methods to cryopreserve and store strains are expensive, time consuming, and require many animals. There is a pressing need to develop a method for cryopreserving strains in a manner which retains the original genotype. The method must be quick, economic, and use few animals. A combination of routine and novel assisted reproductive technologies will be developed to archive and recover homozygous strains. These processes will use 3-5 times fewer resources compared to current embryo cryopreservation methods. Homozygous strains will be archived by cryopreserving both sperm and ovaries. Strains will then be reconstituted using a combination of surgical artificial insemination (surgical AI) and ovarian transplant. Additionally, serial ovarian transplant and surgical oocyte retrieval methods will be explored as alternative methods to recover cryopreserved sperm and ovaries. The reconstitution of strains from the freezer will be developed to reflect the diverse needs of the scientific community and will provide: i) a fast and low cost recovery, delivering 2-3 homozygous breeding pairs, and ii) a moderately fast, higher cost recovery, delivering =10 homozygous breeding pairs. PUBLIC HEALTH RELEVANCE (provided by applicant): Assisted Reproductive Technologies now account for more than 5% of all births in the first world countries. A major limitation to human IVF is the paucity of oocytes. Our research will help understand and, hopefully, increase the oocytes productivity in humans.