Study on population genetic characteristics of Qinchuan cows using microsatellite markers

To evaluate the genetic polymorphisms and to search for available molecular markers for Qinchuan cattle, 90 Qinchuan cows were genotyped with 12 microsatellite markers. A total of 247 alleles were detected, with the number of alleles ranging from 13 (INRA005) to 33 (HEL13), giving a mean number of 21 alleles per locus. The total and mean effective allele number were 142.6229 and 11.8852, respectively. Mean sampling variance of the allele frequency was 2.6036 x 10(-4). Allele size ranges of the 12 microsatellite loci were different. The observed heterozygosity and expected heterozygosity were from 0.7842 (INRA005) to 0.9775 (BM315) and 0.7952 (BM315) to 0.9446 (HEL13), respectively. Mean observed heterozygosity and mean expected heterozygosity were 0.9117 and 0.9047, respectively. Polymorphism information content values were from 0.7653 (INRA005) to 0.9420 (HEL13), and mean polymorphism information content of the 12 microsatellite loci was 0.8965. All the 12 microsatellite loci were highly polymorphic, which showed that there were rich genetic polymorphisms at these detected microsatellite loci in Qinchuan cows. At the 12 microsatellite loci, the mean fixation index was -0.0076, reflecting that the degree of heterozygote defect at these loci was not high and deviations from Hardy-Weinberg equilibrium were not significant.