Genetic factors affecting genetic variance in coarse-wool sheep

The life activity of the rural population in the world is 70% dependent on the traditional animal farming systems based on the domestic livestock breeds. Consequently, it is very important to preserve and enhance the local breeds of animals resistant to any diseases and better adapted to the changing environmental conditions. The environmental factors affecting the genetic structure in 24 coarse-wool breeds of sheep reared in 9 countries of Europe and Asia have been studied. The genetic surveys of twenty microsatellite loci were carried out. The most significant environmental factors causing the genetic variance in the analyzed sheep breeds appeared to be the geographical latitude and the annual mean temperature. The genetic variance of the coarse-wool sheep breeds was generally higher at low geographical latitudes, which corresponds to the data obtained for the other vertebral species. Therefore, the protection of sheep populations inhabiting the areas at the low geographical latitudes can better maintain the intraspecific diversity. This fact should be especially considered when planning the programs to conserve the biodiversity of farm animals. The breeds of sheep reared near the centers of domestication are distributed in the low latitude ranges. They have a higher genetic variance. Therefore, they can serve as the source of genes contributing to adaptation under the conditions of global climate change.