Genetic adaptation to urban living: molecular DNA analyses of wild boar populations in Budapest and surrounding area

Abstract

Studies of wild boar, Sus scrofa Linnaeus 1758, in urban and suburban areas of Budapest, Hungary, have indicated that these populations do not have continuous contact. Based on the assumption that the city has a discrete population, we hypothesized that the urban wild boar would differ genetically from those in suburban areas. Analysis of single-nucleotide polymorphism (SNP) data using the GeneSeek Genomic Profiler (GGP) Porcine 50 K system (Neogen, Scotland, UK) differentiated three populations: Buda (B) from the Western bank of the Danube; Buda Surrounding (BS); and Valkó (V) from the Eastern bank of the Danube. The coefficient of genetic differentiation (FST) for the B and BS populations was low. The inbreeding coefficients of the populations BS and V were close to zero, while population B had a high positive value reflecting the influence of founders and the inbreeding of the continuous urban population. The genome regions that were most differentiated between the B and BS populations were analyzed based on the FST values of the SNP markers using a mixed linear multi-locus model and BayeScan software. The most differentiated marker, WU_10.2_18_56278226, was found on chromosome 18. The surrounding region contained several candidate genes that could play important roles in adaptations related to human-induced stress. Two of these, encoding the adenylate cyclase 1 (ADCY1) and inhibin beta A chain precursor (INHBA) genes, were sequenced. While IHBA gene did not display variation, the allele distribution of the ADCY1 gene in the B population was significantly different from that of the BS population supporting the parapatric differentiation of wild boar.