Population Genetics of Latin American Criollo Cattle
Criollo cattle, descendants of animals brought by Iberian settlers to the Americas, are a group of breeds that have been subjected to centuries of natural and sometimes human-mediated selection in novel agroecological zones. This has resulted in populations that are uniquely adapted to the diverse environments found in Latin America and the Caribbean. Criollo cattle exhibit distinct characteristics such as a resistance to disease and exceptional heat tolerance. In addition to European taurine (Bos taurus) ancestry, it has been proposed that Criollo cattle have experienced gene flow from African taurine and Asian zebu (Bos indicus) populations. In this study we analysed three Criollo breeds (Blanco Orejinegro and Hart?n del Valle from Colombia , and Limonero from Venezuela) using whole genome sequencing data to examine population structure and admixture at very high resolution. We also examined selection signatures associated with a myriad of adaptive traits, revealing genes linked to thermotolerance, reproduction, fertility, and immunity. Our results also provided evidence of artificial selection, particularly for distinct coat and skin coloration traits. We did not detect evidence for historical African taurine admixture in Criollo cattle; however, there was evidence of uniform admixture between the Hart?n del Valle breed and zebu cattle. This study underscores the remarkable adaptability of Criollo cattle, driven by both natural and human-mediated selection. It highlights the genetic richness and potential of these breeds in the face of climate change, habitat flux, and disease challenges. Further research is warranted to validate and leverage these findings for more effective and sustainable cattle breeding programmes.