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Molecular evolution of the insect chemoreceptor gene superfamily in Drosophila melanogaster


Robertson, HM and Warr, CG and Carlson, JR, Molecular evolution of the insect chemoreceptor gene superfamily in Drosophila melanogaster, Proceedings of the National Academy of Sciences of the United States of America, 100, (24) pp. 14537-14542. ISSN 0027-8424 (2003) [Refereed Article]

DOI: doi:10.1073/pnas.2335847100


The insect chemoreceptor superfamily in Drosophila melanogaster is predicted to consist of 62 odorant receptor (Or) and 68 gustatory receptor (Gr) proteins, encoded by families of 60 Or and 60 Gr genes through alternative splicing. We include two previously undescribed Or genes and two previously undescribed Gr genes; two previously predicted Or genes are shown to be alternative splice forms. Three polymorphic pseudogenes and one highly defective pseudogene are recognized. Phylogenetic analysis reveals deep branches connecting multiple highly divergent clades within the Gr family, and the Or family appears to be a single highly expanded lineage within the superfamily. The genes are spread throughout the Drosophila genome, with some relatively recently diverged genes still clustered in the genome. The Gr5a gene on the X chromosome, which encodes a receptor for the sugar trehalose, has transposed from one such tandem cluster of six genes at cytological location 64, as has Gr61a, and all eight of these receptors might bind sugars. Analysis of intron evolution suggests that the common ancestor consisted of a long N-terminal exon encoding transmembrane domains 1-5 followed by three exons encoding transmembrane domains 6-7. As many as 57 additional introns have been acquired idiosyncratically during the evolution of the superfamily, whereas the ancestral introns and some of the older idiosyncratic introns have been lost at least 48 times independently. Altogether, these patterns of molecular evolution suggest that this is an ancient superfamily of chemoreceptors, probably dating back at least to the origin of the arthropods.

Item Details

Item Type:Refereed Article
Keywords:Gustation; Gustatory receptor; Odorant receptor; Olfaction; Taste; trehalose; amino terminal sequence; chemoreceptor; conference paper; Drosophila melanogaster; exon; gene cluster; gene location; genome; intron; molecular evolution; multigene family
Research Division:Biological Sciences
Research Group:Genetics
Research Field:Neurogenetics
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Warr, CG (Professor Coral Warr)
ID Code:131985
Year Published:2003
Web of Science® Times Cited:521
Deposited By:Office of the School of Medicine
Deposited On:2019-04-16
Last Modified:2019-04-16

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