ABSTRACT
To our knowledge, the value of the haploid DNA content (C-value) of Ovis musimon (mouflon) has not been previously published. Therefore, the aim of the present work was to determine the C-value and the nuclear area of O. musimon sperm cells and compare both parameters with those of Ovis aries. Feulgen reaction, which is specific and stoichiometric for DNA, was carried out on semen smears. The C-value and sperm nuclear area were determined using microspectrophotometry and Gallus domesticus erythrocytes as standard species. The C-value of O. musimon was 3.02 ± 0.04 pg, and the sperm nuclear area was 23.92 ± 0.89 µm(2). The C-value and the sperm nuclear area of O. aries were 3.07 ± 0.03 pg and 22.98 ± 0.86 µm(2) respectively. The O. musimon C-value was not significantly different (P > 0.05) from that of O. aries, indicating that both species may have a very close phylogenetic relation.
Subject(s)
DNA/metabolism , Spermatozoa/metabolism , Animals , Male , Sheep , Spectrophotometry/methodsABSTRACT
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.