title: Relationship between stage of development and sex of bovine IVM-IVF embryos cultured in vitro versus in the sheep oviduct.
abstract: We have confirmed more rapid development of male compared with female in vitro-cultured bovine embryos during the first 7 d after in vitro fertilization. The male-to-female sex ratio of expanded blastocysts after 10 d of in vitro culture was 1.37:1.00, which was significantly different from the expected 1:1 ratio, but no deviation from a 1:1 ratio was observed for male and female expanded blastocysts derived from culture of bovine embryos in the sheep oviduct (1.11:1.00). When embryos that developed only to the morula stage were analyzed for sex, a greater number of female than male bovine embryos was observed from in vitro culture but not after culture in the sheep oviduct. Possible causes of these sex-related differences in development of cultured bovine embryos are discussed.
authors.affiliation: Department of Animal Science, University of California, Davis, CA 95616-8521, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gutiérrez-Adán
authors.forename: E
authors.initials: E
authors.lastname: Behboodi
authors.forename: G B
authors.initials: GB
authors.lastname: Andersen
authors.forename: J F
authors.initials: JF
authors.lastname: Medrano
authors.forename: J D
authors.initials: JD
authors.lastname: Murray