抄録
The olfactory receptor (OR) gene family is the largest multigene family in vertebrate genome of which the composition would reflect taxon/species-specific sensory evolution. Chimpanzee (Pan troglodytes) is the closest relative to humans. Study of their OR gene family composition would reveal not only chimpanzee-specific but also human-specific olfactory differentiation. However, the public whole-genome assembly (WGA) of non-human primates would not be as reliable as the human reference WGA. Thus, we applied the targeted capture (TC) for OR genes from a chimpanzee genomic DNA sample to achieve high-depth massive-parallel sequencing using probes designed from the previously deduced set of intact OR genes in the common ancestor of catarrhines. Our TC-based approach successfully retrieved nearly 50 more intact OR genes than the latest chimpanzee WGA databases in which we detected 383 intact OR genes using a published pipeline. We also detected OR segregating disrupted genes with intact and disrupted alleles, which are not informed in the public WGA. These large differences from WGA are likely due to methodological improvements by TC although some differences could be due to intraspecific variation. The results updated identification of duplication and disruption/loss (“birth” and “death”, respectively) events of OR genes during chimpanzee evolution. We also search for OR genes in WGAs of other great apes and human using BLAST. These results revealed species-specific birth and death events during hominid evolution, leading to our better understanding of interrelationship between OR gene family evolution and dietary adaptations in chimpanzees and other hominids.
