Evaluating the impact of the introgression of Iberian wild goats (Capra pyrenaica) by domestic goats (Capra hircus) from a genome-wide perspective

The hybridization of wild species with closely related domesticates is an important threat to their genetic conservation because it can cause maladaptation and outbreeding depression. Herewith, we have genotyped 118 Iberian wild goats from Tortosa-Beceite, Sierra Nevada, Muela de Cortés, Gredos and Batuecas with the Goat SNP50 BeadChip to evaluate the potential impact of hybridization with domestic goats. Weighted principal component and Admixture analyses indicated the existence of eight individuals from Tortosa-Beceite showing signs of introgression with domestic goats. Genomic segments containing introgressed SNPs were enriched in genes related with the immune and neuronal systems. Although the introgression of Iberian wild goats by domestic goats seems to be an episodic rather than a widespread phenomenon, measures should be taken in order to ensure the genetic integrity of Iberian wild goats by avoiding the presence of uncontrolled herds of domestic or feral goats in areas where this wild species thrives. Furthermore, we show that Iberian wild goat populations have a reduced genetic diversity and are strongly differentiated, probably as consequence of strong population bottlenecks and prolonged geographic isolation. In this context, well planned translocations could be an effective strategy to increase the overall genetic variation of isolated Iberian wild goat populations with restricted diversity.