Fertility of sperm from a tetraparental Chimeric bull

The purpose of the present study was to examine the ability of a tetraparental Chimera in producing IVF embryos. Cumulus oocytes complexes (COCs) were matured in vitro for 22 h. Frozen-thawed sperm of a Chimera (CH), as well as Japanese Black (JB), Limousin (L), Japanese Brown (JBr), Holstein (H) bulls were used for IVF. romosome preparations were made from peripheral lymphocytes. Based on chromosome analysis the Chimera had apparently normal chromosomes (29 acrocentric pairs, one large sub metacentric X chromosome and one small sub metacentric Y chromosome). oportion of acrosome reacted spermatozoa after 1 h of incubation was higher (P < 0.01) with the Chimera (CH) than with the Holstein and in Japanese Brown bulls, but did not differ from Japanese Black and Limousin bull sperm (79.0%, 71.2%, 72.5%, 57.8% and 57.0% for CH, JB, L, JBr and H sperm, respectively). ization rates observed after 5 h of sperm-oocyte incubation with Chimera (O-CH) sperm were higher (P < 0.05) than with Japanese Brown (O-JBr) and (P < 0.01) than with Holstein (O-H) sperm, but did not differ from Japanese Black (O-JB) and Limousin (O-L) sperm (3644, 81.8%; 2835, 80.0%; 2536, 69.4%; 1943, 44.2% and 633, 18.2% for O-CH, O-JB, O-L, O-JBr and O-H, respectively). eavage rates of IVM oocytes inseminated with Chimera sperm were also higher (P < 0.001) than in Holstein, (P < 0.01) Japanese Brown and (P < 0.05) Limousin, but did not differ from Japanese Black sperm (181239, 75.7%; 123171, 71.9%; 108186, 58.1%; 80196, 40.8% and 30186, 16.1% for O-CH, O-JB, O-L, O-JBr and O-H, respectively). The blastocyst rates of IVM oocytes inseminated with sperm were higher (P < 0.05) than in Limousin, Japanese Brown and Holstein, but did not differ from Japanese Black (69181, 38.1%; 48123, 39.0%; 27108, 25.0%; 730, 23.3% and 1680, 17.8% for O-CH, O-JB, O-L, O.-JBr and O-H, respectively). findings suggested the sperm from this tetraparental Chimeric bull were able to be used for producing bovine IVF embryos.