Use of FISH technique to study the meiosis process in bulls.

摘要

The aim of this work was to assess the meiosis process in bulls on the basis of observations of the X-Y bivalent. The assessment was made using FISH technique in successive stages of the meiotic division. Gonad specimens were taken postmortem from three Red-and-White Lowland bulls that had originated from the Experimental Station Ltd of the National Research Institute of Animal Production in Grodziec Slaski. The animals were chosen on account of their semen parameters, which were lower than herd average. Meiotic chromosome preparations were made as described by Evans in 1964. Hybridization was carried out using molecular probes that identify bull X and Y chromosomes. A total of 38 spermatogonia and 144 primary spermatocytes at different stages of the meiotic division were tested. The analysis of hybridization signals (red-purple indicating the Y chromosome and yellow indicating the X chromosome) in bull gonad cells did not show any abnormalities in the meiosis process. A 90% dissociated X-Y bivalent was only observed in five spermatocytes at metaphase I. It is therefore concluded that these minor changes did not lower the semen parameters of the investigated animals..