Assessing the levels of intraspecific admixture and interspecific hybridization in Iberian wild goats (Capra pyrenaica)

Abstract

Iberian wild goats (Capra pyrenaica, also known as Iberian ibex, Spanish ibex, and Spanish wild goat) underwent strong genetic bottlenecks during the 19th and 20th centuries due to overhunting and habitat destruction. From the 1970s to 1990s, augmentation translocations were frequently carried out to restock Iberian wild goat populations (very often with hunting purposes), but they were not systematically planned or recorded. On the other hand, recent data suggest the occurrence of hybridization events between Iberian wild goats and domestic goats (Capra hircus). Augmentation translocations and interspecific hybridization might have contributed to increase the diversity of Iberian wild goats. With the aim of investigating this issue, we have genotyped 118 Iberian wild goats from Tortosa-Beceite, Sierra Nevada, Muela de Cortes, Gredos, Batuecas, and Ordesa and Monte Perdido by using the Goat SNP50 BeadChip (Illumina). The analysis of genotypic data indicated that Iberian wild goat populations are strongly differentiated and display low diversity. Only three Iberian wild goats out from 118 show genomic signatures of mixed ancestry, a result consistent with a scenario in which past augmentation translocations have had a limited impact on the diversity of Iberian wild goats. Besides, we have detected eight Iberian wild goats from Tortosa-Beceite with signs of domestic goat introgression. Although rare, hybridization with domestic goats could become a potential threat to the genetic integrity of Iberian wild goats; hence, measures should be taken to avoid the presence of uncontrolled herds of domestic or feral goats in mountainous areas inhabited by this iconic wild ungulate. ; This research was funded by the European Regional Development Fund (FEDER)/Ministerio de Ciencia e Innovación—Agencia Estatal de Investigación/Project Reference grant: PID2019-105805RB-I00 and by the CERCA Programme/Generalitat de Catalunya. We acknowledge the support of the Spanish Ministry of Economy and Competitiveness for the Center of Excellence Severo Ochoa 2020–2023 (CEX2019-000902-S) grant awarded to the Centre for Research in Agricultural Genomics (CRAG). We also acknowledge José Folch, of the Centro de Investigación y Tecnología Agroalimentaria de Aragón for his help in the development of his research. MGLS was funded with a FPI Ph.D. grant from the Spanish Ministry of Education (BES-C-2017-079079). TFC was funded with a fellowship from the CAPES Foundation-Coordination of Improvement of Higher Education, Ministry of Education of the Federal Government of Brazil. EMS was funded with a FPU Ph.D. grant from the Spanish Ministry of Education (FPU15/01733). GM is a Serra Húnter fellow (professor) of the Generalitat de Catalunya. Thanks also to the CERCA Programme of the Generalitat de Catalunya for their support. Sample collection benefitted from the research grants CGL2012-40043-C02-01, CGL2012-40043-C02-02, and CGL2016-80543-P, also from the Spanish Ministry of Economy and Competitiveness.