Genomis modification in consequence of evoulationary separation of goats and sheep

Abstract

Karyotypes of the domestic goat and sheep were evaluated on the basis of morphology, relative lengths and standardized G-and C-banding patterns of chromosomes. The G-banded karyotypes confinned the homology of all goat chromosomes (2n=60) with sheep chromosomes (2n=54) or sheep chromosome anns. Cytogenetic comparisons of the 2 species simultaneously with the standardized cattle karyotype elucidated that during the karyotype evolution there has been a reduction in chromosome number due to centric fusions. The homology of the G-banding pattern in sheep and goat/cattle further revealed a high degree of conservation in linear organization of genetic material. However, a reduction in the genomic length on account of loss of centromeric sequences during centric fusion of goat/cattle acrocentric chromosomes to generate sheep metacentric chromosomes was detected. Comparative cytogenetics, thus, can be a useful tool in elucidating genomic changes in mammalian speciation.