Current state in biotechnology in canine and feline reproduction

Biotechnology has proceeded much further in cats than in canines, although the pregnancy rate after in vitro maturation (IVM), IVC and embryo transfer (ET) is still relatively low. The use of AI with frozen-thawed semen as a breeding tool to overcome breeding incompatibility or to preserve male gene tic material has been limited in felines in contrast to the situation in do mestic dogs and foxes. In many research scenarios and endangered felid spec ies programs, the in vitro production of feline embryos with subsequent tra nsfer has complemented the use of AI. Improvement of IVM, in vitro fertiliz ation (IVF) and embryo culture coupled with ovarian tissue grafting, cryoba nking of follicles, oocytes, semen, or embryos, with subsequent ET into sur rogate females, may render this technology feasible for use in endangered w ild felids, In canines, reliable systems for in vitro production of embryos , embryo cryopreservation and transfer are yet to be developed. The refinem ent of invasive fertilization techniques, such as intracytoplasmic sperm in jection (ICSI), may eventually provide a tool for removal of recipient oocy te nuclei and transfer of selected embryonic or somatic cell donor nuclei i nto domestic cat ooplasm, thereby providing a tool for genetic modification , or for preservation of valuable genetic material. (C) 2000 Elsevier Scien ce B.V. All rights reserved.