Videomicroscopic Comparison of Bull Sperm and Leukocyte Chromosome Areas as Related to Gender

Abstract

Chromosomal areas from metaphase spreads of male bovine leukocytes were digitized and sex chromosomes identified using videomicroscopy. Autosomal areas were ranked in descending order within a cell and assigned to two categories based on alternating rank. X and Y chromosome areas were assigned to respective categories. Areas were divided by 4 to make their sum equivalent to sperm DNA content. Data were analyzed before and after inclusion of sex chromosomal areas. Before X and Y inclusion, rank contributed to difference in chromosomal areas. Rank by category interaction and category effects did not contribute to area variation. After X and Y inclusion, area variation was due to rank by category interaction, rank, and category. Differences between sums of chromosomal areas across categories was 3.57%. Head areas of morphologically normal sperm with intact acrosomes were digitized using the same optics as chromosomal areas. Sum of corrected chromosomal areas per category was used in discriminant analysis to assign sperm head areas to two categories with .5 prior probabilities. Assignment resulted in 1037 sperm in one category and 1177 in the other. Difference between largest sperm head area classes across categories was 3.2%. Discriminatian of sperm head areas, based on sum of chromosomal area and measured with computerized videomicroscopy, may be used to evaluate sex of bovine spermatozoa.