Cytochrome P450 2B diversity in a dietary specialist—the red tree vole (Arborimus longicaudus)

Abstract

Although herbivores rely on liver enzymes to biotransform plant secondary metabolites ingested in plant-based diets, only a few enzymes from a handful of species have been characterized at the genomic level. In this study, we examined cytochrome P450 2B (CYP2B) sequence diversity and gene copy number in a conifer specialist, the red tree vole (Arborimus longicaudus). We fed captive individuals exclusively Douglas-fir (Pseudotsuga menziesii) foliage, cloned and sequenced their liver CYP2B cDNA, and estimated CYP2B gene copy number. We identified 21 unique CYP2B nucleotide sequences, and 20 unique CYP2B amino acid sequences. Gene copy number of CYP2B was estimated at 7.7 copies per haploid genome. We compared red tree vole CYP2B with CYP2B sequences of a generalist, the prairie vole (Microtus ochrogaster), found in GenBank. Our study revealed that the CYP2B enzymes of red tree voles possess unique sequences compared to CYP2B enzymes of other herbivorous species. The unique combination of amino acid residues at key substrate recognition sites of CYP2B enzymes may underlie the ability of the red tree vole to specialize on a highly toxic diet of Douglas-fir.

Duplication, Loss, and Evolutionary Features of Specific UDP-Glucuronosyltransferase Genes in Carnivora (Mammalia, Laurasiatheria)

“…In koala, to deal with their daily eucalypt-specialized diet, their genome seemed to expand CYP2C subfamilies [ 40 ]. Additionally, juniper-specialist woodrat and red tree voles, which have a Douglas fir-specialized diet, observed higher gene copy number of CYPs, compared to closely related generalist species [ 41 , 42 ]. However, these results have been mainly discussed with respect to CYP genes, which were not addressed in the current study.…”

Characteristics of cytochrome P450-dependent metabolism in the liver of the wild raccoon, <i>Procyon lotor</i>

“…This difference between CYP1A and CYP2B in the amount of protein cross-reactive with rat anti-CYP antibody was also observed in a previous study using hepatic microsomal CYP of seal species [ 8 ]. This could be because CYP2B subfamilies have evolved independently and diversified among animal species, unlike CYP1A subfamilies [ 35 , 36 ].…”

MGOS: A Library for Molecular Geometry and its Operating System

“…The use of such resolution-dependent approaches is common despite their unreliable, inconsistent, and sometimes conflicting results [21]. We observe that VOIDOO is still popular in diverse disciplines [22,23,24,25,26,27,28,29,30,31,32] and studies of grid-based algorithms continues [33]. The absence of an overarching analytical theory is because individual researchers have focused on problem-specific, local aspects of geometry problems, concentrating on isolated issues such as surfaces, voids, channels, volumes, areas, and so on.…”