engleski

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Aoudad, Ammotragus lervia, is an ungulate species native to the mountain ranges of North Africa. Six subspecies have been described in its native range, differing in distribution and morphological characteristics. The aoudad was successfully introduced into Europe in the second half of the twentieth century, mainly for hunting purposes, with established populations in Croatia, Italy, and Spain. Previous analysis of mitochondrial DNA showed that the aoudad was introduced to Europe from at least four maternal lineages, but it is not known from which evolutionary units/subspecies the introduced aoudads originated. The aim of our study was to gain insight into adaptive genetic diversity in European populations of aoudad by analyzing exon 2 of the major histocompatibility complex (MHC) class II DRB gene. Between 2016 and 2018, aoudad samples were collected from free- ranging populations from Croatia (Mosor Mountain) and Spain (Sierra Espuña and La Palma Island), and from captive populations from the Czech Republic (near the city of Plzeň) and Spain (Almeria). Using next-generation Ion Torrent sequencing, we detected eight highly divergent alleles in 68 individuals, with three to four alleles present per population. The number of variable nucleotide sites in the detected alleles was 42 out of 236 (18%) and the number of variable amino acid positions in the translated sequences was 23 out of 78 (29%). The high average proportion of shared alleles within the population (0.51) is consistent with the expectations for recently introduced populations funded by a small number of individuals. The two most common alleles had frequencies of 37% and 29%, with the first present in all populations and the second present in all populations except Almeria. We found private alleles in populations from Croatia and the Czech Republic, for which previous study at neutral loci showed a common origin. These private alleles are probably a consequence of the founder effect. In Almeria, a population thought to represent a subspecies of Saharan aoudad, a private allele accounted for 60% of the allele frequency, and this population was genetically the most distinct from the others. The observed differences in DRB alleles between populations are inevitably the result of DRB alleles carried by the founder individuals. Because previous study showed that mitochondrial haplotypes are highly variable in European aoudad populations, more so than is common for the same subspecies of ungulates, observed MHC variability in these populations may also reflect different evolutionary lineages from which the founder individuals originated.

Ammotragus lervia, Barbary sheep, major histocompatibility complex, allelic polymorphism

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