Chromatin cytophotometric analysis of abnormal bovine spermatozoa

Sperm head morphology is basically conditioned by the nuclear structure. The aim of the present work was to study the relation between nuclear morphological features, DNA content and chromatin distribution in morphologically normal vs. abnormal bovine spermatozoa. To this end, individual Feulgen-reacted spermatozoa were cytophotometrically studied. Chromatin compactation was evaluated by means of nuclear area, as well as mean and maximal absorbance of each nucleus. Morphological abnormality analysed included large, small, pear, narrow and round shapes, together with presumably 'diploid' sperms. Both large and small spermatozoa have a DNA content that does not differ significantly from normal values, but their area and mean and maximal absorbance are significantly different. Size variation seems basically due to altered chromatin compactation. The pear shapes have a narrower neck and a significant increase in maximal absorbance alone, which is invariably recorded in the neck zone whose increase would indicate a change in distribution and/or compactation. The narrow and round shapes fail to present significant variations in studied parameters. The possible 'diploids' differ significantly from normal cells in all studied variables, with a little area increase.