engleski

Signatures of selection and environmental adaptation across East Adriatic sheep breeds

Sheep are one of the most important livestock species in Croatia, found predominantly in the coastal and mountain areas along the East Adriatic, with farming that is primarily extensive. In the present study, we have sampled 200 individuals belonging to eight sheep breeds (Istria sheep, Krk Island sheep, Cres Island sheep, Rab Island sheep, Lika sheep, Pag Island sheep, Dalmatian Pramenka, Dubrovnik Ruda sheep). East Adriatic sheep are the closest populations to a world-wide distinctive group of Balkan sheep populations, which has never been analysed for selection signals and environmental adaptation. We have genotyped all sampled animals with Ovine Infinium® HD SNP BeadChip (606, 006 SNPs). After quality control, four different approaches that identify selection signatures were performed ; a) identification of extremely frequent SNPs in runs of homozigosity (eROHi), c) Integrated Haplotype Score (iHS), c) across populations identification of SNPs with extremely high FST values (ehFST) and d) across populations Integrated Haplotype Score (Rsb) based on the ratio of extended haplotype homozygosities between populations. While the eROHi and IHS analyses were performed within each population, ehFST and Rsb analyses were performed in contrast to internationally known sheep breeds. Subsequently, we have analysed and compared all significant SNPs (regions) with respect to breed and used methodologies, while potential candidate genes were identified and classified according to their biological function. This study contributes to the better understanding of the environmental adaptation and genomic architecture of the East Adriatic sheep populations.

signatures of selection ; environmental adaptation ; East Adriatic sheep breeds

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