Potential Adaptive Introgression From Dogs in Iberian Grey Wolves (Canis lupus)

Invading species along with increased anthropogenization may lead to hybridization events between wild species and closely related domesticates. As a consequence, wild species may carry introgressed alleles from domestic species, which is generally assumed to yield adverse effects in wild populations. The opposite evolutionary consequence, adaptive introgression, where introgressed genes are positively selected in the wild species, is possible but has rarely been documented. Grey wolves (Canis lupus) are widely distributed across the Holarctic and frequently coexist with their close relative, the domestic dog (C. familiaris). Despite ample opportunity, hybridization rarely occurs in most populations. Here we studied the geographically isolated grey wolves of the Iberian Peninsula, who have coexisted with a large population of loosely controlled dogs for thousands of years in a human-modified landscape. We assessed the extent and impact of dog introgression on the current Iberian grey wolf population by analysing 150 whole genomes of Iberian and other Eurasian grey wolves as well as dogs originating from across Europe and western Siberia. We identified almost no recent introgression and a small (< 5%) overall ancient dog ancestry. Using a combination of single scan statistics and ancestry enrichment estimates, we identified positive selection on six genes (DAPP1, NSMCE4A, MPPED2, PCDH9, MBTPS1, and CDH13) for which wild Iberian wolves carry alleles introgressed from dogs. The genes with introgressed and positively selected alleles include functions in immune response and brain functions, which may explain some of the unique behavioural phenotypes in Iberian wolves such as their reduced dispersal compared to other wolf populations.

This research was funded by Junta de Andalucía (‘Proyectos de generación de conocimiento’ P18-FR-5099 to J.A.L and C.V.); I.S. received a PhDfellowship, ‘Ayudas para la formación de profesorado Universitario (FPU)’ from the Spanish Ministry of Universities (FPU17/02584) and a research contract by ‘Asociación Apadrina La Ciencia’ co-funded by the Ford Motor Company Fund. This research was also partly funded by the WOLFNESS project within the Biodiversa+ program, the European Biodiversity Partnership under the 2021–2022 BiodivProtect joint call for research proposals, co-funded by the European Commission (GA N101052342) and the Spanish Ministry of Science and Innovation (PCI2022-135098-2). We acknowledge support of the publica-tion fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICi).

Peer reviewed