title: A method for chromosome analysis of ram spermatozoa using zona-free hamster oocytes.
abstract: A method for displaying ram spermatozoan chromosomes using the interspecific zona-free hamster oocyte penetration was described to distinguish X- and Y-bearing spermatozoa. Semen samples from four rams were frozen and stored in liquid nitrogen. After thawing the samples, motile spermatozoa were collected by the swim-up method and treated with ionophore A23187 for the purpose of facilitating their capacitation. Slides were prepared by the gradual fixation-air dry method. The rates of oocyte penetration, first cleavage metaphase, and the number of ova that were karyotyped successfully were 67.9, 60.8 and 40.6%, respectively. The overall success rate (number of spermatozoa karyotyped/number of oocytes used for insemination) was 47.9%. A total of 1009 spermatozoa were analyzed, and the ratio of X- and Y-bearing spermatozoa was 508:501.
authors.affiliation: Department of Biological Sciences Asahikawa Medical College Asahikawa 078, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tateno
authors.forename: M
authors.initials: M
authors.lastname: Akaike
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
authors.forename: Y
authors.initials: Y
authors.lastname: Kamiguchi
authors.forename: K
authors.initials: K
authors.lastname: Mikamo