Genetic diversity, Population Genetic Structure and Conservation Management of Spanish Verata Goat Breed

Abstract

Abstract Verata goat is an endangered autochthonous breed from Extremadura (Spain). Genetic diversity, genetic Bottleneck hypothesis and population genetic structure were analysed for conservation management purposes. Twenty-two microsatellite markers were used to genotype 570 animals belonging eight different sampling regions. Average number of alleles per locus (9.09 ± 0.71) and the expected gene diversity (He = 0.694 ± 0.025) revealed substantial genetic variation in the breed, even greater than other Spanish and European breeds not threatened. The decrease of heterozygotes in the total population (FIT = 0.075) is a consequence of the population's subdivision (FST = 0.063), instead of inbreeding in subpopulations (FIS = 0.014). The FST value was similar to those obtained in other Spanish goat breeds. Clustering analysis performed by STRUCTURE software and by the modal value of the distribution of the ΔK showed clear membership of individuals in four clusters. Clear genetic drift of Verata goat population has been observed, as it was demonstrated by the assignment of individuals to pre-defined sampling regions. Also, it was detected a certain degree of genetic flow (immigrant and admixed animals) among the sample herds located in these regions. Verata goat population had not undergone a genetic bottleneck at least in the recent past; however, a recent population expansion without immigration or the introduction of some unique or rare alleles by immigrants has been detected. Based on the above results, we have designed a conservation program based on maintaining of live animals in a conservation nucleus with a minimum coancestry mating system and constant family sizes and on the cryopreservation of germplasm. The development of this program will allow us the maintenance and sustainable use of the breed in its geographical and socio-economic environment, preserving racial purity of animals and the variability of the breed.