Tre, han, Gr5A1, trehalose receptor
Gene model reviewed during 5.42
Gene model reviewed during 5.50
There is only one protein coding transcript and one polypeptide associated with this gene
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Gr5a using the Feature Mapper tool.
Comment: Expressed in a subset of gustatory receptor neurons
GBrowse - Visual display of RNA-Seq signalsView Dmel\Gr5a in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
The symbol used in FlyBase for this gene has been changed from "Tre" (Trehalose-sensitivity) to "Gr5a" (Gustatory receptor 5a) to match the format used for other gustatory receptor genes, and to avoid confusion with the neighbouring "Tre1" (Trapped in endoderm 1) gene.
Although FBrf0128502 reported that Tre1, which maps extremely close to Gr5a, mediates the trehalose response, the balance of evidence suggests that Gr5a, rather than Tre1, encodes a trehalose receptor.
The "CG15779"/"Gr5a" gene corresponds to the "Trehalose-sensitivity" complementation group as opposed to the "CG3171" gene, as was reported in FBrf0128502.
Expression of mRNAs in mutant flies, expression analysis in wild-type flies and amino acid polymorphism data suggest that the "Gr5a" and not "CG3171" corresponds to the "Tre" (Trehalose-sensitivity) locus.
Evidence from FBrf0138267 (expression of mRNAs in mutant flies, expression analysis in wild-type flies and amino acid polymorphism data) suggests that the CG15779 gene prediction (Gr5a) corresponds to the "Trehalose-sensitivity" locus, mutation of which results in low sensitivity to trehalose. The "Trehalose-sensitivity" locus does not correspond to "Tre1" from FBrf0128502 which corresponds to the CG3171 gene prediction (which is adjacent to and divergently transcribed from CG15779). Mutation of Tre1 may also affect the sensitivity of flies to trehalose since mutants affecting Tre1 also show low sensitivity to trehalose which can be rescued by overexpression of Tre1 (FBrf0128502).
Gr5a encodes a taste receptor required for response to the sugar trehalose, but not for response to sucrose, indicating a role for G protein-mediated signalling in the transduction of sweet taste.
Encodes a gustatory sugar receptor involved in the response to trehalose.
Genetic evidence suggests Gr5a is the structural gene for the trehalose receptor. Trehalose sensitivity decreases in females carrying half the normal dosage of Gr5a, but does not increase with an increase in Gr5a dosage. Changes in sensitivity of several aneuploid flies suggest there is an upper limit to the number of molecules that can be incorporated into the receptor membrane.