title: Bacterial origin of a diverse family of UDP-glycosyltransferase genes in the Tetranychus urticae genome.
abstract: UDP-glycosyltransferases (UGTs) catalyze the conjugation of a variety of small lipophilic molecules with uridine diphosphate (UDP) sugars, altering them into more water-soluble metabolites. Thereby, UGTs play an important role in the detoxification of xenobiotics and in the regulation of endobiotics. Recently, the genome sequence was reported for the two-spotted spider mite, Tetranychus urticae, a polyphagous herbivore damaging a number of agricultural crops. Although various gene families implicated in xenobiotic metabolism have been documented in T. urticae, UGTs so far have not. We identified 80 UGT genes in the T. urticae genome, the largest number of UGT genes in a metazoan species reported so far. Phylogenetic analysis revealed that lineage-specific gene expansions increased the diversity of the T. urticae UGT repertoire. Genomic distribution, intron-exon structure and structural motifs in the T. urticae UGTs were also described. In addition, expression profiling after host-plant shifts and in acaricide resistant lines supported an important role for UGT genes in xenobiotic metabolism. Expanded searches of UGTs in other arachnid species (Subphylum Chelicerata), including a spider, a scorpion, two ticks and two predatory mites, unexpectedly revealed the complete absence of UGT genes. However, a centipede (Subphylum Myriapoda) and a water flea and a crayfish (Subphylum Crustacea) contain UGT genes in their genomes similar to insect UGTs, suggesting that the UGT gene family might have been lost early in the Chelicerata lineage and subsequently re-gained in the tetranychid mites. Sequence similarity of T. urticae UGTs and bacterial UGTs and their phylogenetic reconstruction suggest that spider mites acquired UGT genes from bacteria by horizontal gene transfer. Our findings show a unique evolutionary history of the T. urticae UGT gene family among other arthropods and provide important clues to its functions in relation to detoxification and thereby host adaptation.
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany; National Institute of Horticultural and Herbal Science, Rural Development Administration, 441-440 Suwon, Korea. Electronic address: sahn@ice.mpg.de.
authors.forename: Seung-Joon
authors.initials: SJ
authors.lastname: Ahn
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium.
authors.forename: Wannes
authors.initials: W
authors.lastname: Dermauw
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium.
authors.forename: Nicky
authors.initials: N
authors.lastname: Wybouw
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium; Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
authors.forename: Thomas
authors.initials: T
authors.lastname: Van Leeuwen
mesh_terms: D000818:Animals; D001181:Arthropods / Q000201:enzymology / Q000235:genetics; D003400:Astacoidea / Q000201:enzymology / Q000235:genetics; D033361:Cladocera / Q000201:enzymology / Q000235:genetics; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D016678:Genome; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D007438:Introns; D010802:Phylogeny; D040102:Tetranychidae / Q000201:enzymology* / Q000235:genetics*; D015262:Xenobiotics / Q000378:metabolism / Q000633:toxicity
chemical_list: D015262:Xenobiotics; D016695:Glycosyltransferases
keywords: Arthropoda; Chelicerata; Detoxification; Horizontal gene transfer; Tetranychus urticae; UDP-glycosyltransferase