Abstract:UDP-glycosyltransferase (UGT) catalyzes the transfer of glycosyl groups (e.g., glucuronic acid) to exogenous or endogenous chemicals and plays an important role in conjugation reactions. In vertebrates, UGT genes are divided into 5 families: UGT1, UGT2, UGT3, UGT5, and UGT8. Among these UGT enzymes, UGT1 and UGT2 enzymes are known to be important xenobiotic metabolizing enzymes in mammals. However, little is known about UGT1 and UGT2 genes in avian species. In this study, we therefore aimed to classify avian U… Show more
“…However, a previous study suggested that the UGT2 genes in the common ancestor of mammals do not play a role in hepatic xenobiotic metabolism (8). In this study, the phylogenetic tree of the 2nd-6th exons demonstrate that the UGT2 genes may have independently diversified in Eutheria and Marsupialia after Cretaceous period and that several duplications of UGT2B genes separately occurred in each eutherian family.…”
Section: Discussionmentioning
confidence: 50%
“…However, a previous study suggested that the UGT2 genes in the common ancestor of mammals do not have diversity and do not play a role in hepatic xenobiotic metabolism (8). In this study, phylogenetic analysis of the 1st exons in UGT2 genes that is related to aglycone recognition (64), reveals that marsupial UGT2 genes, which are composed of variable 1st exons and constant exons similar to eutherian UGT2A1 and UGT2A2, formed two different clades with eutherian UGT2A and UGT2B genes.…”
Section: Discussionmentioning
confidence: 68%
“…Similar to mammals, the number of UGT1E genes and the conjugation activity are low in carnivorous birds. However, unlike in mammals, the number of UGT2 family genes (n ≤ 3) is generally consistent in many bird species (8,9). These studies suggest that the mammalian and avian UGT1 and UGT2 family genes are independently diversified and evolved.…”
The UDP-glucuronosyltransferase (UGT) gene family is responsible for the transfer of glucuronic acid to exogenous and endogenous chemicals. Based on the highly diversified number of genes, the mammalian UGT1A and UGT2B subfamily genes are believed to be involved in the conjugation reactions of xenobiotic metabolism. However, it is speculated that the UGT2 family genes are not involved in the xenobiotic metabolism of avian species due to the less diverse number of genes. In this study, we aimed to investigate the evolutionary history of mammalian UGT1 and UGT2 family genes and determine when the diversification of UGT2B genes occurred. We also attempted to identify the main factors responsible for the diversification of UGT genes. By examining the genomic information and feeding habits of 67 species representing each mammalian family, we discovered that the UGT2B genes emerged in the Eutheria on or after Cretaceous period and that their number were higher in plant-eating mammals (herbivore or omnivore) than in carnivorous mammals. We also found that the UGT2B genes in some herbivorous mammals underwent positive selection. In contrast, the diversity of the UGT1 family genes was inherited from the common ancestor of birds and mammals. Thus, our findings suggest that the emergence of angiosperms (flowering plants) and the occurrence of “animal–plant warfare” influenced the evolution of this gene family involved in the xenobiotic metabolism of eutherians. Furthermore, future research investigating the marsupials and birds that do not possess UGT2B genes is required to elucidate the mechanisms underlying the metabolism of chemical substances in these species.
“…However, a previous study suggested that the UGT2 genes in the common ancestor of mammals do not play a role in hepatic xenobiotic metabolism (8). In this study, the phylogenetic tree of the 2nd-6th exons demonstrate that the UGT2 genes may have independently diversified in Eutheria and Marsupialia after Cretaceous period and that several duplications of UGT2B genes separately occurred in each eutherian family.…”
Section: Discussionmentioning
confidence: 50%
“…However, a previous study suggested that the UGT2 genes in the common ancestor of mammals do not have diversity and do not play a role in hepatic xenobiotic metabolism (8). In this study, phylogenetic analysis of the 1st exons in UGT2 genes that is related to aglycone recognition (64), reveals that marsupial UGT2 genes, which are composed of variable 1st exons and constant exons similar to eutherian UGT2A1 and UGT2A2, formed two different clades with eutherian UGT2A and UGT2B genes.…”
Section: Discussionmentioning
confidence: 68%
“…Similar to mammals, the number of UGT1E genes and the conjugation activity are low in carnivorous birds. However, unlike in mammals, the number of UGT2 family genes (n ≤ 3) is generally consistent in many bird species (8,9). These studies suggest that the mammalian and avian UGT1 and UGT2 family genes are independently diversified and evolved.…”
The UDP-glucuronosyltransferase (UGT) gene family is responsible for the transfer of glucuronic acid to exogenous and endogenous chemicals. Based on the highly diversified number of genes, the mammalian UGT1A and UGT2B subfamily genes are believed to be involved in the conjugation reactions of xenobiotic metabolism. However, it is speculated that the UGT2 family genes are not involved in the xenobiotic metabolism of avian species due to the less diverse number of genes. In this study, we aimed to investigate the evolutionary history of mammalian UGT1 and UGT2 family genes and determine when the diversification of UGT2B genes occurred. We also attempted to identify the main factors responsible for the diversification of UGT genes. By examining the genomic information and feeding habits of 67 species representing each mammalian family, we discovered that the UGT2B genes emerged in the Eutheria on or after Cretaceous period and that their number were higher in plant-eating mammals (herbivore or omnivore) than in carnivorous mammals. We also found that the UGT2B genes in some herbivorous mammals underwent positive selection. In contrast, the diversity of the UGT1 family genes was inherited from the common ancestor of birds and mammals. Thus, our findings suggest that the emergence of angiosperms (flowering plants) and the occurrence of “animal–plant warfare” influenced the evolution of this gene family involved in the xenobiotic metabolism of eutherians. Furthermore, future research investigating the marsupials and birds that do not possess UGT2B genes is required to elucidate the mechanisms underlying the metabolism of chemical substances in these species.
“…Additionally, eight UGT ( K00699 ) genes were found in the unique gene families of African arowana. UGT genes have been shown to play a critical role in many metabolism pathways such as ascorbate and aldarate metabolism, retinol metabolism, steroid hormone biosynthesis, and porphyrin & chlorophyll metabolism, which might be related to its special omnivorous diet character ( Kakehi et al., 2015 ; Kawai et al., 2018 ) ( Table S9 , q-value<0.01). Figure 4 Gene Family Dynamics of Three Osteoglossidae Fishes (A) The venn diagram represents the overlap relationship of three Osteoglossidae fishes' gene families.…”
Summary
Osteoglossiformes
is a basal clade of teleost, evolving since the Jurassic period. The genomes of
Osteoglossiformes
species would shed light on the evolution and adaptation of teleost. Here, we established a chromosome-level genome of African arowana. Together with the genomes of pirarucu and Asian arowana, we found that they diverged at ∼106.1 million years ago (MYA) and ∼59.2 MYA, respectively, which are coincident with continental separation. Interestingly, we identified a dynamic genome evolution characterized by a fast evolutionary rate and a high pseudogenization rate in African arowana and pirarucu. Additionally, more transposable elements were found in Asian arowana which confer more gene duplications. Moreover, we found the contraction of olfactory receptor and the expansion of UGT in African arowana might be related to its transformation from carnivore to be omnivore. Taken together, we provided valuable genomic resource of
Osteoglossidae
and revealed the correlation of biogeography and teleost evolution.
“…101) Their activity per dry weight of tissue in chicks decreased in the order of duodenum ≒liver>mid-intestine>rectum. 27) Incidentally, through a detailed sequence analysis of the UDPGT genes in 43 avian species, Kawai et al 100,103) showed the presence of UDPGT1E and UDPGT2 genes, which are further classified into six and three groups, respectively; feeding habits may affect not only the number of UDPGT1E genes but also the hepatic enzyme activity (carnivorous sp.<omnivorous and herbivorous sp.). A search of the chicken expressed sequence tag database has identified two cDNA clones that represent SULT subfamilies 1B and 1C.…”
Section: Other Enzymes Relevant To Conjugationmentioning
The median lethal dose of pesticide in acute oral toxicity, used as a conservative index in avian risk assessment, varies by the species with differences of less than one order of magnitude, depending on body size, feeding habit, and metabolic enzyme activity. The profiles of pesticide metabolism in birds with characteristic conjugations are basically common to those in mammals, but less information is available on their relevant enzymes. The higher toxicity of some pesticides in birds than in mammals is due to the lower activity of avian metabolic enzymes. The bioaccumulation in birds is limited for very hydrophobic pesticides resistant to metabolic degradation. Several in silico approaches using the descriptors of a pesticide molecule have recently been employed to estimate the profiles of acute oral toxicity and bioaccumulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
