Genome-wide Detection Of Selection Signatures In Sheep Populations With Use Of Population Differentiation Index F_ST

Selection signatures are the selective footprints across the organism genome due to the effect of selection in the process of artificial selection, which displayed the long range linkage disequilibrium in chromosome or genetic diversity reduction. With the high density genome-wide SNP chip development and detecting genome footprints gets within touch.This study is based on Illumina Ovine SNP50 chip genotyping data of three populations, the population differentiation index FST were performed to detect selection signatures, and the genes located within selection signature regions were found by bioinformatics analyses.The experiment population included Sunite sheep, German Mutton sheep and Dorper sheep, which sums 316 individuals belonging to 66,159 and 93 respectively. The quality control was performed by Plink with the standard of individual call rate and SNP call rate greater than 0.90 respectively, Minor allele Frenquency greater than 0.03. The results of indentifying selection signatures in autosome show that 343 outilers were detected. In this study, the regions of selection signatures were defined that extended 50kb toward two directions.365 genes in the selection signatures regions were found, some of them were related to reproduction, meat quality and growth-realted traits, such as IGF2PB3, IGF1R, BMP2, BMPR1B and CAPN3.After GO analyses, we found these candidate genes enriching in the GO terms related to metabolic process and demethylation.Detecting selection signatures in X chromosome, the top 5% loci was selected for selection signatures.The results of indentifying selection in X chromosome shows that 61 locis were detected. The regions of selection signatures were defined extended 100kb toward two directions around outlier site,98 genes in the selection signatures regions were found, some of them were related to reproduction and lipid metabolism, such as BOCR, ACSL4, MAOA and MAOB.some of them are X-linked disease genes.Most of them have not been reported in sheeps so far, which might serve as important candidate genes in future study.