Specific cytogenetic labeling of bovine spermatozoa bearing X or Y chromosomes using fluorescent in situ hybridization (FISH)

X and Y specific probes were identified in order to apply the fluorescent i n situ, hybridization (FISH) technique to bovine spermatozoa. For Y chromos ome detection, the BRY4a repetitive probe, covering three quarters of the c hromosome, was used. For X chromosome detection, a goat Bacterial Artificia l Chromosome (BAC) specific to the X chromosome of bovine and goats and giv ing a strong FISH signal was used. Each probe labeled roughly 45% of sperm cells. The hybridization method will be useful for evaluating the ratio of X- and Y- bearing spermatozoa in a sperm sample and consequently can be use d to evaluate the efficiency of sperm sorting by different techniques such as flow cytometry.