Genetic diversity of creole chickens in Valles Centrales, Oaxaca, using microsatellite markers

The population of creole chickens in small-scale farms is remarkably diverse and part of the poultry genetic reservoir in Mexico. Furthermore, this population represents a vital protein source for rural families. The genetic variability of creole chicken populations in the central region of Oaxaca was determined in blood samples collected from 109 creole chickens belonging to 17 populations and 30 Plymouth Rock chickens (control group). Ten microsatellite markers were used to detect a total of 109 alleles, with an average of 10.9 +/- 3.1 alleles per locus. The observed heterozygosity (Ho) ranged from 0.575 (San Lucas) to 0.750 (San Antonio 2); the expected heterozygosity ranged from 0.625 (Control) to 0.733 (Huixtepec 2). Overall, it was observed an increase in the number of heterozygotes, evidenced by a global-level inbreeding (FIT) of 0.042; the FST population differentiation index was moderate (0.059), and the inbreeding of individuals within populations (FIS) was negative (-0.017), which indicates an excess of heterozygotes at that level. Cluster analysis grouped the Nazareno, ITVO, San Lucas, and San Antonio populations, indicating that these creole chicken populations are isolated and genetically differentiated in some characteristics. This information is important to design future conservation, selection, and multiplication programs for this species at the backyard level in the central region of Oaxaca, Mexico.