Genetic characterization and implications for conservation of the last autochthonous Mouflon population in Europe

Abstract

Population genetic studies provide accurate information on population structure, connectivity, and hybridization. These are key elements to identify units for conservation and define wildlife management strategies aimed to maintain and restore biodiversity. The Mediterranean island of Sardinia hosts one of the last autochthonous mouflon populations, descending from the wild Neolithic ancestor. The first mouflon arrived in Sardinia ~ 7000 years ago and thrived across the island until the twentieth century, when anthropogenic factors led to population fragmentation. We analysed the three main allopatric Sardinian mouflon sub-populations, namely: the native sub-populations of Montes Forest and Mount Tonneri, and the reintroduced sub-population of Mount Lerno. We investigated the spatial genetic structure of the Sardinian mouflon based on the parallel analysis of 14 highly polymorphic microsatellite loci and mitochondrial D-loop sequences. The Montes Forest sub-population was found to harbour the ancestral haplotype in the phylogeny of European mouflon. We detected high levels of relatedness in all the sub-populations and a mitochondrial signature of hybridization between the Mount Lerno sub-population and domestic sheep. Our findings provide useful insights to protect such an invaluable genetic heritage from the risk of genetic depletion by promoting controlled inter-population exchange and drawing informed repopulation plans sourcing from genetically pure mouflon stocks.

Islands as Time Capsules for Genetic Diversity Conservation: The Case of the Giglio Island Mouflon

“…The 18 mouflon sequences clustered in five haplotypes (Hpt-6 to 9 and h11), according to the results inferred from the analysis of the genetic variability and haplotype diversity previously reported. Hpt-6 and Hpt-7 were found to be closely related to haplotypes Hpt-1 and Hpt-4, both previously described in the Sardinian mouflon [14], whereas Hpt-9 appeared closer to continental Europe mouflons.…”

“…Hpt-7 is positioned between Hpt-1 and Hpt-4 in the median-joining network (Figure 2). Both Hpt-1 and Hpt-4 are of Sardinian origin, suggesting that Hpt-7 represents a residual trace of the original Sardinian mouflon variability [14]. Similarly, SSR analyses showed private alleles in the Giglio mouflons, indicating that this population harbours exclusive genetic variability.…”

“…Overall, 24 mouflon specimens were sampled, including 15 from Giglio Island, one from Elba, seven from Sardinia, and seven from Corsica. Importantly, the Sardinian individuals were selected from a previous study [14] to maximise their representativeness of the Sardinian mouflon diversity and contrast the small sample size. Additionally, two individuals of Sarda, a modern domestic Sardinian breed, were included.…”

“…The dataset was extended including 88 O. gmelini sequences retrieved from Satta and colleagues [14] to better cover the geographical distribution of the species. We included sequences representative of mouflons from the islands of Sardinia (54) and Corsica (2), and from mainland Europe (3).…”

“…To evaluate the population diversity and structure, samples were genotyped at 14 Simple Sequence Repeats (SSR) loci retrieved from literature [14]. The amplification products were obtained according to Scali and colleagues [19] and subjected to fine sizing by capillary electrophoresis using an ABI 3130 DNA analyser (Applied Biosystems).…”