The genome landscape of Hong Kong feral cattle as a unique genetic resource

In the Hong Kong Special Administrative Region of China, there is a feral cattle population that has not been well characterized genetically. In this study, we used high-coverage (∼30×) whole-genome sequencing from 30 Hong Kong feral (HKF) cattle and compared them to 116 individuals from four representative populations worldwide. Our analyses revealed that the HKF cattle have high genetic diversity in the face of a declining effective population size, suggesting their substantial and yet untapped genetic potential. We also identified introgression events that occurred prior to the divergence between HKF cattle and other East Asian indicine populations, which shaped the adaptation of HKF cattle in Asian agro-ecologies. Moreover, we identified positive selection in HKF cattle for environmental adaptation, particularly in traits related to heat tolerance, bone strength, and coat color. Our findings provide insights into the genetic origin and unique adaptation of HKF cattle.