Genetic Diversity of a Chinese Native Chicken Breed, Bian Chicken, Based on Twenty-nine Microsatellite Markers

Abstract

The level of genetic differentiation and genetic structure in a Chinese native chicken breed, Bian chicken, and two controlled chicken populations (Jinghai chicken and Youxi chicken in China) were analysed based on 29 microsatellite markers. A total of 166 distinct alleles were observed across the 3 breeds, and 32 of these alleles (19.3%) were unique to only I breed. Bian chicken carried the largest number of private alleles at 15 (46.9%), followed by the Jinghai chicken with 12 private alleles (37.5%). The average polymorphism information content (0.5168) and the average expected heterozygote frequency (0.5750) of the Bian chicken were the highest, and those of the Jinghai chicken were 0.4915 and 0.5505, respectively, which were the lowest. Among 29 microsatellite loci, there were 15 highly informative loci in Bian chicken, and the other 14 were reasonably informative loci. The highly informative loci in Jinghai chicken and Youxi chicken were 17 and 14 respectively. Significant deviations from the Hardy-Weinberg equilibrium were observed at several locus-breed combinations, showing a deficit of heterozygotes in many cases. As a whole, genetic differentiation among the breeds estimated by the fixation index (Fst) were at 6.7% (p<0.001). The heterozygote deficit within population (Fis) was 22.2% (p<0.001), with the highest (0.249) in Bian chicken and lowest (0.159) in Youxi chicken. These results serve as an initial step in the plan for genetic characterization and conservation of the Chinese chicken genetic resource of Bian, as well as Jinghai and Youxi chickens.