Genome-wide analyses reveal population structure and identify candidate genes associated with tail fatness in local sheep from a semi-arid area

Under a climate change perspective, the genetic make-up of local livestock breeds showing adaptive traits should be explored and preserved as priority. We used genotype data from ovine 50 k Illumina BeadChip for assessing breed autozygosity based on runs homozygosity (ROH) fine-scale structure detecting genomic regions under selection in 63 Tunisian sheep samples. The average inbreeding coefficients ROH were estimated at 0.017, 0.021, 0.024 Barbarine (BAR, n = 26), Noire de Thibar (NDT, 23), Queue fine l'Ouest (QFO, 14) breeds, respectively. relationships among individuals identity by state (IBS) distance matrix highlighted recent introgression QFO into BAR differentiation NDT samples, possibly explained past European gene pools. Genome-wide scan across within sample set identified an outstanding signal chromosome 13 (46.58–49.61 Mbp). These results confirmed using FST index, differentiating fat vs. thin-tailed individuals. Candidate genes pressure (CDS2, PROKR1, BMP2) associated to lipid storage probably preferentially selected fat-tailed animals. Our findings suggest paying more attention preserve integrity alleles breeds.