Genomic Insights into the Origin, High Fecundity and Environmental Adaptation of Hu Sheep.

Hu sheep are renowned for their adaptation to high-temperature, humid environments and their high fecundity. Despite serving as the founder species for sheep breeding in China, the genetic mechanisms underlying these desirable traits and the breed's origin have remained unresolved. To address the longstanding challenges in understanding their adaptations and origins, comprehensive analyses utilizing genetic data is conducted from over 300 Hu sheep and ≈200 other Chinese native sheep. The study unveils the migration history of sheep and the formation of the Hu sheep in eastern China. By employing multiple screening methods, this study identifies that the BMPR1B, UNC5C, and GRID2 synergistically contribute to the high fecundity trait in Hu sheep. The coexistence of beneficial genotypes in these genes increase the likelihood of multiple births. Notably, the results suggest a potential coevolution between environmental adaptation and reproductive traits in this breed. Overall, the study provides novel insights into the genetic origin and adaptation of Hu sheep, offering new perspectives for molecular breeding in sheep and other livestock species.