Genetic variation of European mouflon depends on admixture of introduced individuals

Abstract In mainland Europe, mouflon were first introduced in the 18th and 19th centuries, mainly in Germany, Austria, the Czech Republic, Slovakia, and Hungary. In the early 20th century, mouflon were introduced in Croatia, while all introductions in Slovenia occurred in the 1950s and 1960s. Since the introduction, populations in both countries have remained largely stable, with occasional declines and increases in some areas. Due to several up-following introduction events, also using individuals with unknown origin, the genetic pool of the species might be very admixed; however, no genetic study has been made to date. Therefore, our aim was to: i) determine the origin of introduced mouflon in Slovenia and Croatia, ii) compare the neutral and adaptive genetic make-up of introduced populations. In genetic analyses, which were performed at neutral loci (partial fragment of mitochondrial control region, mtDNA CR) and adaptive major histocompatibility complex (MHC; DRB exon 2) using the next generation sequencing approach, we also included individuals from Germany, France (Corsica), Italy (Sardinia), and the Czech Republic. The haplotype network based on mtDNA CR showed that most analysed mouflon from Slovenia shared the same haplotypes or were closely related to mouflon from Germany and Sardinia, and a few shared the same haplotypes as most mouflon from Croatia. Croatian mouflon from all studied populations shared the same or close haplotypes with individuals from the first Croatian population established in Brijuni Island National Park (northern Adriatic Sea) in the early 20th century. Similar results for populations in both countries were revealed by MHC genes. According to the genetic data, the population origins are generally in agreement with the written historical records, although there are indications of the introduction or release of extra individuals into certain colonies where historical data is lacking. Furthermore, our findings validate that both mitochondrial and MHC genetic diversity are useful tools for investigating the paths of translocation.