vermillion, TDO, Tryptophan 2,3-dioxygenase
Gene model reviewed during 5.45
There is only one protein coding transcript and one polypeptide associated with this gene
Homotetramer. Dimer of dimers.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\v using the Feature Mapper tool.
The 1.4kb v transcript is first detected in 12-24hr embryos. Levels remain relatively constant throughout larval development, although a higher level is observed in early third instar than in late third instar larvae. A dramatic decline is seen in the pupal stage and relatively high levels are again detected in 2 to 3 day old adults.
v+37 transcripts are expressed in adults at a level sufficient to give a wild type phenotype. They are expressed at a level comparabe to that of vk transcripts in a su(s)6 vk genotype which is about 24% of the wild type v transcript level. In a su(s)38 or su(s)35 background the levels of v+37 transcripts are raised to 59% and 50% of wild type, respectively.
GBrowse - Visual display of RNA-Seq signalsView Dmel\v 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.
Source for identity of: v CG2155
Two regions, -300bp to -600bp and -60bp to-160bp, are important for maximal levels of expression in adults. Larval expression is fat body specific; expression depends on sequences between +19 and +36. This downstream element can be functionally replaced by a TATA box in vivo. When added to the wild type v promoter, a TATA element augments the level of v transcription by three to five fold.
The eye color of v1 mutants is bright scarlet owing to absence of brown ommochrome; ocelli are colorless. Flies with the mutant combination v1; bw1 have white eyes. Though v1, v2 and vk are suppressed by mutations at the su(s) locus (FBrf0002306; FBrf0008670; FBrf0013364; FBrf0013329; FBrf0014641; FBrf0017063; FBrf0020623; FBrf0064831), other v alleles (v36f, v48a, v51a, v51b, v51c and vE1) show no change in the mutant eye color with su(s) alleles and little or no increase in tryptophane oxidase activity (small increase observed in su(s) v36f flies). Starvation has no effect on eye color of unsuppressed v alleles.
Suppressor and reversion mutations exert an effect on pre-mRNA splicing.
Hereditary reversion of the eye color of v mutants to that of wild-type flies has been achieved by treatment of eggs with DNA.
In mutant larvae tryptophane in the fat body is not converted into kynurenine.
v alleles suppressed by mutation at the su(s) locus fail to accumulate nonprotein tryptophane and partially restore tryptophane oxidase activity in spite of the mutation at v. Tryptophane oxidase activity is absent in v1 mutants.
Certain v alleles (v1, v2 and vk) are suppressed by mutations at the su(s) locus; these mutants show wild-type eye color. Some brown pigment is formed under conditions of partial starvation in su(s) suppressed v mutants.
Nonprotein tryptophane is accumulated in v mutant flies rather than converted into N-formylkynurenine and then into formic acid and kynurenine.
The diffusible v+ involved in mosaic and transplantation experiments has been identified as kynurenine.
Morgan, Nov. 1910.