Evolution of the CYP2B subfamily gene in primates and its relationship to diet

Herbivores rely heavily on liver enzymes to deal with plant secondary metabolites (PSMs) due to their consumption on plant-based diets, but only a small amount of enzymes have been described based on the genomic level. It is suggested that a multigene subfamily, cytochrome P450 2B ( CYP2B ), involved in PSMs processing. However, CYP2B subfamily genes of only several rodent species have been characterized, and the copies of CYP2B gene have been compared between the specialist and generalist. Here we investigated the phylogeny of CYP2B subfamily genes in primates with known genome sequences, and related the number of gene to the diet. Furthermore, we compared the CYP2B subfamily genes in two closely related species, Macaca assamensis and Ma. mulatta, , which can be viewed as specialist (mainly feeds on Bonia saxatilis) ) and generalist, respectively, to examine whether the difference of gene number or sequence diversity exists between these two species. The result showed that, most primates have only one CYP2B subfamily gene, although several herbivores have two copies; and both Ma. assamensis and Ma. mulatta have one CYP2B subfamily gene, each with 8 SNPs in them, which is mainly because that multiple SNPs can lead to higher diversity, and further can help deal with various toxins. Physicochemical property prediction indicated that some of these SNPs may cause radical variations between the gene functions. This study is a comprehensive exploration on the evolution of a detoxification enzyme gene subfamily in the primate group, and provides an initial genetic foundation to explore how the closely related species respond to diet from the perspective of P450.