GENETIC RELATIONSHIPS BETWEEN NATIVE SHEEP BREEDS IN NIGERIA BASED ON MICROSATELLITE DNA POLYMORPHISMS.

Abstract

Genetic relationship among Nigeria's breeds of sheeps and crosses was studied using microsatellite DNA polymorphisms. DNA samples extracted from four Nigeria's breeds of sheeps (West African Dwarf,the balami, Uda and yankassa) and crosses were analysed using 30 microsatellite markers for diversity studies. Twenty of the makers were by the sheeps genome . Nineteen of the loci were polymorphic and were used to calculate genetic distances (Ds) between the based on allelefrequences of microsatellite. The phylogenetic relatioship between the breeds were similarly estimated. With the total number of loci studied, 285 alleles were generated and a high decree of heterozysity was recorded, (0.57 to 0.72), a relative high degree of relaibility could be placed on the tree topology with the relationship between breeds potraying a closer relationship between the yankassa and Uda (Ds 0.356). The genetic distance (Ds) was 0.432, 0.534 and 0.665 between the African Dwarf and the Yankassa, Uda and Balami respectively also indictating a closer relatioship between the Yankassa, and the WAD compared to the basically Northern breeds (Uda and Balami). This further confirms the evolutionary divergence of the breeds which makes them distint entitles. The data suggests that microsatellite DNA markers are useful tools for studying the genetic relationship among these sheeps breeds. The high polymorphic alleles could thus be exploited in breeds improvement and development.