Variants in BMP15 Gene Affect Promoter Activity and Litter Size in Gobi Short Tail and Ujimqin Sheep

Reproductive performance in sheep plays a crucial role in determining the economic efficiency of the industry, with increasing litter size being a key focus for genetic improvement. The <i>BMP15</i> gene is widely recognized as a major gene influencing sheep fertility. In this study, specific mutations in the <i>BMP15</i> gene of Gobi short tail sheep were identified through direct sequencing, and these mutations were genotyped using the MassARRAY system. The g.54285159_54285161TTA indel was significantly associated with litter size in Gobi short tail sheep (<i>p</i> < 0.05). Three mutations, including g.54291460G>A, g.54288671C>T, and the g.54285159_54285161TTA indel, were significantly associated with litter size in Ujimqin sheep (<i>p</i> < 0.05). Furthermore, the promoter activity analysis demonstrated that the A allele exhibited significantly higher promoter activity compared to the G allele of the g.54291460G>A mutation. These findings highlight valuable genetic markers for improving sheep litter size and provide a robust theoretical foundation for further research on the <i>BMP15</i> gene's role in reproduction.