NUCLEAR TRANSFER EMBRYOS IN THE HORSE

B. REGGIO, M. SANSINENA, R.A. COCHRAN, A. GUITREAU, J.A. CARTER, R.S. DENNISTON AND R.A. GODKE

Havemeyer Foundation Monograph Series

R & W Publications (Newmarket) Limited

Lugar: Sufflok, UK; Año: 2001 vol. 3 p. 45 - 46

1472-3158

After the recent births of healthy foals produced from intracytoplasmic sperm injection by this laboratory (Cochran et al. 1998), an attempt was made to produce cloned horses embryos using similarly harvested oocytes from live mares (Meintjes et al. 1995) (Part I). Oocyte availability is one of the major limitations in conducting nuclear transfer studies in many species. In the horse, oocyte collection is cumbersome and often seasonal, thus potentially limiting to the success of a nuclear transfer program. In a study conducted by Dominko et al. (1999) bovine oocytes were used as recipients of nuclear transfer of various mammalian species (rat, cow, sheep, pig, monkey and rat). Regardless of the species of donor fibroblasts used in this study, all couplets progressed through the first cell cycle, and some reconstructed embryos developed to the blastocysts stage. Since the timing of the first two cleavage divisions in bovine in vitro-produced embryos corresponded more closely to the timing of cleavage in other the donor nucleus species, bovine oocytes were used in the second part of this study (Part II).