Luvoni G C
Institute of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Milan, Italy.
Reprod Nutr Dev. 2000 Sep-Oct;40(5):505-12. doi: 10.1051/rnd:2000114.
The objective of the development of assisted reproduction techniques in dogs and cats is their application to non-domestic canine and feline species, most of which are considered threatened or endangered. Among these techniques, an entirely in vitro system for embryo production is effectively an important tool for conservation of wildlife. In the last decade, progress has been made in embryo production in carnivores. It has been shown that canine oocytes can resume meiosis in vitro and that these oocytes can be fertilized and developed in vitro, although at a much lower rate than most other domestic animal oocytes. The reason lies in the dissimilarities of reproductive physiology of the dog compared to other species and the lack of precise information concerning the oviductal environment, in which oocyte maturation, fertilization and early embryonic development take place. Successful in vitro embryo production in the domestic cat has been attained with oocytes matured in vitro, and kittens were born after transfer of IVM/IVF derived embryos. On the basis of these results the in vitro fertilization of oocytes has also been applied in several non-domestic feline species. The effectiveness of such protocols in the preservation of genetic material of rare species can be improved by developing better techniques for long-term storage of gametes. In dogs and cats sperm cells have been successfully frozen and the cryopreservation of oocytes would greatly increase their availability for a range of reproductive technologies. Cryopreserved cat oocytes can be fertilized successfully and their development in vitro after fertilization is enhanced when mature oocytes are frozen. Thus refined techniques of oocyte maturation and fertilization in vitro coupled with oocyte cryopreservation could allow for an easy establishment of genetic combinations when male and female gametes in the desired combination are not simultaneously available, and the propagation of endangered carnivores would be facilitated.
犬猫辅助生殖技术发展的目标是将其应用于非家养的犬科和猫科物种，其中大多数被视为受威胁或濒危物种。在这些技术中，一个完全体外的胚胎生产系统实际上是保护野生动物的重要工具。在过去十年中，食肉动物的胚胎生产取得了进展。已经表明，犬类卵母细胞可以在体外恢复减数分裂，并且这些卵母细胞可以在体外受精并发育，尽管其速率比大多数其他家畜卵母细胞低得多。原因在于犬类与其他物种相比生殖生理的差异，以及缺乏关于输卵管环境的确切信息，而卵母细胞成熟、受精和早期胚胎发育都发生在输卵管环境中。通过体外成熟的卵母细胞已在家养猫中成功实现了体外胚胎生产，并且在移植体外成熟/体外受精衍生的胚胎后生出了小猫。基于这些结果，卵母细胞的体外受精也已应用于几种非家养猫科物种。通过开发更好的配子长期储存技术，可以提高此类方案在保护稀有物种遗传物质方面的有效性。在犬猫中，精子细胞已成功冷冻，卵母细胞的冷冻保存将大大增加其在一系列生殖技术中的可用性。冷冻保存的猫卵母细胞可以成功受精，并且当成熟卵母细胞冷冻时，其受精后的体外发育会得到增强。因此，体外卵母细胞成熟和受精的精细技术与卵母细胞冷冻保存相结合，当所需组合的雌雄配子不能同时获得时，可以轻松建立遗传组合，并有助于濒危食肉动物的繁殖。
