Genetic diversity and structure in Criolla Negra goats in Queretaro, Mexico

Since their introduction to Mexico goats have undergone a long process of adaptation and selection, resulting in highly rustic local animals. However, importation of improved breeds has led to the extinction of some regional breeds. For example, the Criolla Negra goat breed is known for its rusticity and high milk quality, but is in decline. A genetic characterization was done of a Criolla Negra population. Hair samples were collected in three goat herds located in different municipalities of the state of Queretaro, Mexico: Cadereyta de Montes (n= 7); El Marques (n= 11); and San Juan del Rio (n= 27). Thirty microsatellites were used to quantify the number of alleles per marker (NA), median number of alleles (MNA), number of effective alleles (NEA), observed heterozygosis (Ho), expected heterozygosis (He), polymorphic data content (PDC), the fixation index (FIS) and Hardy Weinberg equilibrium (HWE). The Criolla Negra population was compared to thirteen breeds forming part of the BioGoat project. Genetic diversity was found to be high in this population. A total of 243 alleles were identified with an MNA of 8.1 alleles per marker. The markers were informative (PDC= 0.06) for polymorphism. The He (0.71) and Ho (0.62) values indicate a slight imbalance in the population. Reynolds genetic distance results showed the Criolla Negra breed to be genetically furthest from the Anglonubia breed and nearest the Murciano-Granadina breed. The studied Criolla Negra goat population exhibits a breed structure well differentiated from the other breeds in the analysis.