Association Analyses between Single Nucleotide Polymorphisms in ZFAT , FBN1 , FAM184B Genes and Litter Size of Xinggao Mutton Sheep.

Simple Summary: FBN1, ZFAT and FAM184B have been screened as candidate genes for the reproduction of sheep. Therefore, it is necessary to verify these genes in the population and determine the associated loci for litter size. The association of litter size with the genotypes of three candidate genes was analyzed using the fixed effects model in Xinggao mutton sheep. The results showed that the g.160338382 T > C in FBN1 was significantly associated with litter size in Xinggao mutton sheep and that this effect was independent of the FecB mutation. Overall, this study provides a useful genetic marker for improving sheep fecundity. Previous studies have screened key candidate genes for litter size in sheep, including fibrillin-1 (FBN1), family with sequence similarity 184 member B (FAM184B) and zinc finger and AT-hook domain containing (ZFAT). Therefore, it is necessary to verify these genes in the Xinggao mutton sheep population and determine the associated loci for litter size. In this study, three loci (FBN1 g.160338382 T > C, FAM184B g.398531673 C > T and ZFAT g.20150315 C > T) were firstly screened based on the population differentiation coefficient between the polytocous and monotocous sheep groups. Then, population genetic analysis and association analysis were performed on these loci. The results revealed that the g.160338382 T > C in FBN1 was significantly associated with the litter size of sheep. Moreover, there was no significant interaction effect between the g.160338382 T > C locus and FecB on litter size. Notably, g.160338382 T > C is adjacent to the anterior border of exon 58 and belongs to a splice polypyrimidine tract variant, which may lead to alternative splicing and ultimately cause changes in the structure and function of the protein. In summary, our results provided a potentially effective genetic marker for improving the litter size of sheep. [ABSTRACT FROM AUTHOR]