Insights into Adaption and Growth Evolution: A Comparative Genomics Study on Two Distinct Cattle Breeds from Northern and Southern China

Mongolian cattle (MG, Bos taurus) and Minnan cattle (MN, Bos indicus) are two different breeds of Chinese indigenous cattle, representing North type and South type, respectively. However, their value and potential have not yet been discovered at the genomic level. In this study, 26 individuals of MN and MG were sequenced for the first time at an average of 13.9- and 12.8-fold, respectively. Large numbers of different variations were identified. In addition, the analyses of phylogenetic and population structure showed that these two cattle breeds are distinct from each other, and results of linkage disequilibrium analysis revealed that these two cattle breeds have undergone various degrees of intense natural or artificial selection. Subsequently, 496 and 306 potential selected regions (PSRs) were obtained in MN and MG, containing 1,096 and 529 potential selected genes (PSGs), respectively. These PSGs, together with the analyzed copy number variation (CNV)-related genes, showed potential relations with their phenotypic characteristics, including environmental adaptability (e.g., DVL2, HSPA4, CDHR4), feed efficiency (e.g., R3HDM1, PLAG1, XKR4), and meat/milk production (e.g., PDHB, LEMD3, APOF). The results of this study help to gain new insights into the genetic characteristics of two distinct cattle breeds and will contribute to future cattle breeding.