BULL SPERM HEAD MORPHOMETRY RELATED TO ABNORMAL CHROMATIN STRUCTURE AND FERTILITY

This study investigated the relationship between morphologically abnor mal sperm, sperm chromatin structure, and fertility. Semen samples wer e obtained from 13 bulls. The sperm chromatin structure assay (SCSA), a sensitive measure of denaturability of sperm nuclear DNA in situ fol lowing acid treatment, was performed on each sample to quantitate abno rmal chromatin structure. Feulgen-stained sperm head morphology was me asured by computerized image analysis (ONCOR-Image): Sixteen parameter s were measured for each of 200 nuclei per sample. Fertility estimates were available for nine of the bulls. The SCSA variable S alpha(t) wa s correlated with fertility ranking (r = 0.617, P < 0.01). No correlat ions were seen between means of the imaging variables and SCSA variabl es %COMP alpha(t) or SD alpha(t). Significant correlations (P < 0.05) were seen between SD alpha(t) and the variation of imaging variables e ccentricity, width, and Light blobs. Significant correlations (P < 0.0 5) were seen between %COMP alpha(t) and the variation of imaging varia bles area, perimeter, p2a, bending energy, nmac, sphericity, eccentric ity, length, and width. A regression model for fertility rankings inco rporating the standard deviation of the imaging variables area, bendin g energy, nmac, eccentricity, condensity, light blobs, and dark blobs was highly significant (r(2) = 0.999, P < 0.05). These results indicat e that variation of morphometry measurements is likely a sensitive bio marker related to fertility potential and abnormal chromatin structure . (C) 1996 Wiley-Liss, Inc.