First Report on Standard G-Banded Karyotype of Nili-Ravi Buffalo, Bubalas bubalis

The present study was planned to determine if chromosomal dysmorphology based on G band nomenclature is common in the Nili-Ravi buffalo which is the prime dairy breed thriving predominantly in the Punjab Province of Pakistan. Microscopic screening of 50 good quality metaphase cells from each of 34 male and female buffalo calves revealed the expected chromosome complement of 24 autosomal pairs and a pair of sex chromosomes XY and XX. A complete G-band homology was noticed between Pakistani Nili-Ravi and earlier investigated karyotypes for water buffalo in India and Italy. Morphology of all metaphase chromosomes examined was normal with five pairs being sub-metacentric chromosomes, whereas the other autosomes including X and Y were classed as acro-subacrocentric. During this study we observed that trypsinization time for optimal G-bands was highly variable and individual chromosomes were identified by marker G-positive and negative bands. X chromosome, the largest acrocentric chromosome, had light G positive-negative bands in the upper middle length distal to the centromere.