Population Structure Analysis of Globally Diverse Bull based on 1000 Bull Genome data Genomes

investigators: N.C. Chung, J. Szyda, M. Frąszczak
Population Structure Analysis of Globally Diverse Bull based on 1000 Bull Genome data

Since domestication, population bottleneck, breed formation, and selective breeding have radically shaped the genealogy and population structure of Bos taurus. In turn, characterization of population structure among globally diverse bull genomes enables detailed assessment of genetic resources and origins, as well as informs genome-wide association studies, genomic selection, and breeding programs. By analyzing 432 unrelated bull genomes from 13 breeds and 16 countries, we demonstrate genetic diversity and structural complexity among the global bull population. Importantly, we relaxed a strong and potentially invalid assumption of discrete or admixed population, by adapting latent variable probabilistic models for individual-specific allele frequencies which directly capture a wide range of complex structure from genome-wide genotypes. We identified highly complex and continuous population structure that contribute to pervasive genetic differentiation in bull genomes. As measured by magnitude of differentiation, selection pressure on SNPs within genes is substantially greater than that on intergenic regions. Additionally, broad regions of chromosome 6 harboring largest genetic differentiation suggest recent positive natural selection underlying population structure. We carried out gene set analysis using SNP annotations to identify highly enriched functional categories such as energy-related processes and multiple development stages (sexual, respiratory, and embryonic). Our comprehensive analysis of bull population structure may support genetic management strategies that capture structural complexity and promote sustainable genetic breath.