Yak (Bos Grunniens) Sperm Nuclei Morphology, Morphometry and DNA Content

The aim of this study was to describe the morphology, morphometry and determine the DNA content of yak sperm nuclei (Bos grunniens). Nuclear morphology observations were performed using light microscopy on slides stained with Feulgen reaction. Abnormalities percentages were determined: pyriform (1.2%), globose (0.2%), small (0.2%), elongated (0.1%). Morphometric measurements were made from digitized images of sperm nuclei stained with the Feulgen reaction. Mean values and standard deviations were obtained: area 21.98 ± 2.60 μm2, length 7.34 ± 0.33 μm, width 3.78 ± 0.27 μm, perimeter 88 ± 19.26 μm, roundness 1.27 ± 0.04, elongation 1.95 ± 0.11 and equivalent diameter 5.28 ± 0.27 μm. According to our knowledge this is the first time that haploid DNA content is determined. In this species 3.42 pg value that was similar to that measured in other species of the family Bovidae and other higher mammals.