A scan for signatures of selection in Russian Romanov sheep breed based on ROH hot spots analysis

Abstract The world-famous Romanov breed of sheep fits easily into different production systems including private households, smallholders, and large farms. Such a resilience and extraordinary reproduction traits combining with good meat qualities have made the Romanov breed as a choice to produce mutton in the Central Russia regions. However, little is known on genetic mechanisms underlying the complex of specific traits of this breed. In this regard, we performed a scan of signatures of selection by identification of runs of homozygosity (ROH) islands in the Romanov sheep population. Forty-eight samples of the Romanov sheep from the Yaroslavl and Kaluga regions of Russia were genotyped using Ovine Infinium® HD SNP BeadChip (Illumina, CA, USA). ROHs were estimated in the R package “detectRUNS” using window-free method for consecutive. The ROH shared in more than 50% of sheep were considered as ROH islands. The genes overlapped with the ROH islands were annotated using Ensembl genome browser 103. Enrichment for functional categories of the identified genes was performed using DAVID Functional Annotation Bioinformatics Microarray Analysis tool. More than 88 SNPs were found in ROH islands located on OAR1, OAR10, OAR11, OAR13, OAR14, OAR15, OAR16, OAR17 and OAR18. We detected a major group of genes related to reproduction traits. The identified candidates included UBE2Q1 (embryo implantation, fertilization, prolactin secretion), RNF17 (spermiogenesis), HSD11B2 (pregnancy, follicle function), FANCA (gonad development), and CUBN (embryonic development). In addition, several identified genes were involved in fatty acid metabolism (ACOX1, HAO2, and EIF6), lipid transport (OSBPL11), and biosynthesis of lipid-binding serum glycoproteins (BPIFB4) as well as in osteoblast differentiation (ADAR). The studies will be continued on a larger sample with further validation of the most promising candidate genes. Genotyping of twenty-four samples was performed within RFBR project No. 20-516-56002. Other twenty-four SNP-genotypes were generated within the theme No. 0445-2019-0024.