Search results for "SHEEP BREEDS"
showing 5 items of 15 documents
Linkage disequilibrium and genetic diversity estimation in three Sicilian autochthonous dairy sheep breeds
2014
Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. In the present study, we used the OvineSNP50K BeadChip to characterize LD, identify haplotype blocks and to analyze genetic diversity in the Valle del Belice (VDB), Comisana (COM) and Pinzirita (PIN) dairy sheep breeds. LD between adjacent SNPs and for all pairwise combinations of SNPs on each chromosome was measured using r2. Haplotype blocks were estimated using D’ based method. Genetic diversity and Principal Component Analysis (PCA) were calculated using PLINK. Small differences in average LD value for adjace…
Genetic diversity and phylogenetic relationships among four breeds reared in Sicily using β-lactoglobulin promoter region polymorphisms
2011
The aim of this work was to analyze the genetic diversity and the phylogenetic relationships among the Valle del Belice (VDB) breed and the other sheep breeds considered as ancestors, using -lactoglobulin (BLG) promoter region polymorphisms. The BLG promoter region of 50 randomly chosen animals from the four breeds (VDB n=20; Comisana (COM) n=10; Pinzirita (PIN) n=10; Sarda (SAR) n=10) were sequenced and aligned, and results showed the presence of 36 single nucleotide polymorphisms (SNPs) and one deletion. The number of polymorphic sites identified showed high variability within breeds. Nucleotide (π) and haplotype (Hd) diversity were estimated with DnaSP software, whereas PHASE software w…
Selection signatures of fat tail in sheep
2017
The investigation of the genes with a role in lipid metabolism enjoy considerable scientific and commercial interest because of the strong correlations between fat deposition and the risk of cardiovascular disease. The fat tail characteristic of sheep is the adaptive response to harsh environment, and beyond representing a valuable energy reserve for facing future climate changes provides clues for elucidating the physiology of fat deposition. Studies on various sheep populations detected fat-tail signatures on chromosomes 2, 3, 5, 6, 7 and 13. Fat-tailed sheep represent about 25% of the world’s sheep population, and the genes with a role in this phenotype are likely not the same for every …
A Combined Multi-Cohort Approach Reveals Novel and Known Genome-Wide Selection Signatures for Wool Traits in Merino and Merino-Derived Sheep Breeds.
2019
Merino sheep represents a valuable genetic resource worldwide. In this study, we investigated selection signatures in Merino (and Merino-derived) sheep breeds using genome-wide SNP data and two different approaches: a classical F-ST-outlier method and an approach based on the analysis of local ancestry in admixed populations. In order to capture the most reliable signals, we adopted a combined, multi-cohort approach. In particular, scenarios involving four Merino breeds (Spanish Merino, Australian Merino, Chinese Merino, and Sopravissana) were tested via the local ancestry approach, while nine pair-wise breed comparisons contrasting the above breeds, as well as the Gentile di Puglia breed, …