Resequencing of reindeer genomes provides clues to their docile habits

Reindeer have long been served as vital subsistence resources for inhabitants of Arctic and subarctic regions owing to their domestication. However, the evolutionary relationships and divergence times among different reindeer populations, genetic traits that distinguish domesticated reindeer, and factors that contribute to their relative docility compared with that of other Cervidae specie, remain unclear. In this study, we sequenced the genomes of 32 individuals from wild and domestic reindeer populations that inhabit Arctic and subarctic regions. We found that reindeer experienced 2 or more independent domestication events characterized by weak artificial selection pressure and limited significant differences in genomic parameters between wild and domestic populations. Alterations in conserved noncoding elements in the reindeer genomes, particularly those associated with nervous system development, may have contributed to their domestication by rendering the nervous system less responsive. Together, our results suggest that inherent species-specific traits, rather than intense artificial selection, may have played a significant role in the relatively docile behavior of reindeer and offer valuable insights into the domestication process of these animals. The domestication of various species has significantly benefited human life and production. However, the genetic mechanisms that underlie domestication vary among the species. Reindeer, an important domesticated species in Arctic and subarctic regions, have played a crucial role in improving human livelihoods in those areas. Understanding when and how different reindeer populations were domesticated requires further investigation. We found that reindeer underwent at least 2 independent domestication events. Interestingly, compared with many other domesticated species (e.g., zebu cattle, dogs, and sheep), reindeer experienced fewer artificial selection pressures, and a clear distinction between wild and domestic reindeer is not evident. However, we detected greater variation in neurological development-related elements in the genome of ancestral populations of both wild and domestic reindeer compared with those in the genomes of other Cervidae species. These genetic variations likely contribute to the inherent docility of reindeer, making them more amenable to domestication.