FlyBase Gene Report: Dmel\v

General Information

Symbol

Dmel\v

Species

D. melanogaster

Name

vermilion

Annotation Symbol

CG2155

Feature Type

protein_coding_gene

FlyBase ID

FBgn0003965

Gene Model Status

Current

Stock Availability

28127 publicly available

Enzyme Name (EC)

tryptophan 2,3-dioxygenase (1.13.11.11)

Gene Summary

vermilion (v) encodes a cytosolic heme-dependent tryptophan 2,3-dioxygenase that catalyzes the oxidative cleavage of the L-tryptophan producing N-formyl-L-kynurenine. v is involved in the production of L-kynurenine, a precursor of the eye pigment ommochromes. [Date last reviewed: 2026-02-19] (FlyBase Gene Snapshot)

All Summaries

Gene Snapshot
Alliance
Auto summary
Gene Group
UniProtKB
Red Book
Interactive Fly

Also Known As

vermillion, TDO, ver, Tryptophan 2,3-dioxygenase

Key Links

Genomic Location

Cytogenetic map

9F11-9F11

Sequence location

X:10,923,972..10,925,631 [+]

Recombination map

1-33

RefSeq locus

NC_004354 REGION:10923972..10925631

Sequence

Get Decorated FASTA

Genomic Maps

JBrowse

Other Genome Views

The following external sites may use different assemblies or annotations than FlyBase.

Function

Gene Ontology (GO) Annotations (9 terms)

Molecular Function (3 terms)

Terms Based on Experimental Evidence (2 terms)

CV Term

Evidence

References

enables heme binding

inferred from direct assay

(Huang et al., 2013)

enables L-tryptophan 2,3-dioxygenase activity

inferred from direct assay

(Huang et al., 2013)

Terms Based on Predictions or Assertions (3 terms)

CV Term

Evidence

References

enables heme binding

inferred from biological aspect of ancestor with PANTHER:PTN000015587

(GO Reference Genome Project, 2011-)

inferred from electronic annotation with InterPro:IPR004981, InterPro:IPR037217

(InterPro Project Members, 2004-)

inferred from sequence or structural similarity with UniProtKB:Q17P71

(Gene Ontology Curators, 2002-)

enables L-tryptophan 2,3-dioxygenase activity

inferred from sequence or structural similarity with UniProtKB:Q17P71

(Gene Ontology Curators, 2002-)

inferred from electronic annotation with InterPro:IPR004981

(InterPro Project Members, 2004-)

inferred from biological aspect of ancestor with PANTHER:PTN000015587

(GO Reference Genome Project, 2011-)

traceable author statement

(Rongvaux et al., 2003)

enables metal ion binding

inferred from electronic annotation with InterPro:IPR037217

(InterPro Project Members, 2004-)

Biological Process (5 terms)

Terms Based on Experimental Evidence (3 terms)

CV Term

Evidence

References

involved_in L-kynurenine metabolic process

inferred from mutant phenotype

(Campesan et al., 2011)

involved_in ommochrome biosynthetic process

inferred from mutant phenotype

(Tearle, 1991)

involved_in protein homotetramerization

inferred from direct assay

(Huang et al., 2013)

Terms Based on Predictions or Assertions (2 terms)

CV Term

Evidence

References

involved_in compound eye pigmentation

traceable author statement

(Rongvaux et al., 2003)

involved_in L-tryptophan catabolic process

inferred from sequence or structural similarity with UniProtKB:Q17P71

(Gene Ontology Curators, 2002-)

traceable author statement

(Rongvaux et al., 2003)

Cellular Component (1 term)

Terms Based on Experimental Evidence (0 terms)

Terms Based on Predictions or Assertions (1 term)

CV Term

Evidence

References

located_in cytosol

inferred from sequence or structural similarity with UniProtKB:P48775

(Gene Ontology Curators, 2002-)

Gene Group (FlyBase)

UNCLASSIFIED DIOXYGENASES

Pathway (FlyBase)

L-TRYPTOPHAN CATABOLISM

Protein Family (UniProt)

Belongs to the tryptophan 2,3-dioxygenase family. (P20351)

Protein Signatures (InterPro)

Catalytic Activity (EC/Rhea)

L-tryptophan 2,3-dioxygenase activity

L-tryptophan + O2 = N-formyl-L-kynurenine (1.13.11.11)

RHEA 24536:

Summaries

Gene Snapshot

Gene Group (FlyBase)

UNCLASSIFIED DIOXYGENASES -: This group comprises dioxygenases that do not classify under other groups in FlyBase.

Pathway (FlyBase)

L-TRYPTOPHAN CATABOLISM -: L-tryptophan is an essential amino acid. Besides its role in protein biosynthesis, L-tryptophan is converted in the cytosol to L-kynurenine, which is then used to synthesize eye pigment ommochromes. In addition, L-tryptophan is a precursor for the biosynthesis of neurotransmitter serotonin and melatonin. Unlike in mammals, L-tryptophan cannot be used to produce NAD(+) or catabolised to acetyl-CoA because Dmel has no homolog of kynureninase that converts L-kynurenine to 3-hydroxyanthranilate. (Adapted from FBrf0161620, FBrf0256069 and PMID:29989284.)

Protein Function (UniProtKB)

Heme-dependent dioxygenase that catalyzes the oxidative cleavage of the L-tryptophan (L-Trp) pyrrole ring and converts L-tryptophan to N-formyl-L-kynurenine. Catalyzes the oxidative cleavage of the indole moiety (PubMed:23333332). Required during larval growth to control the level of potentially harmful free tryptophan in the hemolymph. In the adult the same reaction is the first step in the ommochrome biosynthetic pathway (PubMed:2108317).

(UniProt, P20351)

Phenotypic Description (Red Book; Lindsley and Zimm 1992)

v: vermilion

The v+ gene, expressed in the eyes, fat body, and Malpighian tubules of the wild type (Nissani, 1975, Genet. Res. 26: 63-72), is believed to code for the enzyme tryptophane oxidase (also known as tryptophane pyrrolase)(EC 1.3.11.11), a 150,000 dalton protein that catalyzes the conversion of tryptophane into N-formylkynurenine. The eye color of v mutants is bright scarlet owing to absence of brown ommochrome; ocelli are colorless. Flies with the mutant combination y;w have white eyes. The eye color is wild type in genetically v eyes of gynandromorphs mosaic for wild type and v tissue (Sturtevant, 1932), indicating the non-autonomous nature of the vermilion gene. v eye disks develop wild-type pigmentation when transplanted into wild-type larvae (Beadle and Ephrussi, 1936). yw nuclei from preblastoderm stages implanted into the posterior end of a fertilized v;bw egg can produce a mosaic fly with brown eyes (Zalokar, 1973, Dev. Biol. 32: 189-93). The diffusuble v+ hormone of Beadle and Ephrussi involved in mosaic and transplantation experiments has been identified as kynurenine (Butenandt, Weidel, and Becker, 1940, Naturwissenschaften 28: 63-64). Activity of the inducible enzyme tryptophane oxidase is absent in v mutants (Baglioni, 1959, 1960). As a result, nonprotein tryptophane is accumulated in vermilion flies (Green, 1959) rather than converted into N-formylkynurenine and then into formic acid and kynurenine. In mutant larvae tryptophane in the fat body is not converted into kynurenine (Rizki, 1963; Rizki and Rizki, 1968). Certain v alleles (v1, v2, and vk) are suppressed by mutations at the su(s) locus; these mutants show wild-type eye color, fail to accumulate nonprotein tryptophane, and partially restore tryptophane oxidase activity in spite of the mutation at v (Schultz and Bridges, 1932; Green, 1952; Baglioni, 1960; Shapard, 1960; Kaufman, 1962; Marzluf, 1965; Tartof, 1969; Jacobson et al., 1982); other v alleles (v36f, v48a, v51a, v51b, v51c, and vE1) show no change in the mutant eye color with these su(s) alleles and little or no increase in tryptophane oxidase activity (small increase observed in su(s) v36f flies). Some brown pigment is formed under conditions of partial starvation in suppressed v mutants (Tatum and Beadle, 1938; Shapard, 1960), but starvation has no effect on unsuppressed v alleles.

Gene Model and Products

Number of Transcripts

Number of Unique Polypeptides

Please see the JBrowse view of Dmel\v for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)

Isoform displayed:

Pfam protein domains

InterPro name

classification

start

end

Protein Domains (via SMART)

Isoform displayed:

SMART protein domains

InterPro name

classification

start

end

Structure

Protein 3D structure (Predicted by AlphaFold) (AlphaFold entry P20351)

If you don't see a structure in the viewer, refresh your browser.

Model Confidence:

Very high (pLDDT > 90)
Confident (90 > pLDDT > 70)
Low (70 > pLDDT > 50)
Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures

Crossreferences

PDB - An information portal to biological macromolecular structures

Comments on Gene Model

Gene model reviewed during 5.45

Transcript Data

Annotated Transcripts

Name

FlyBase ID

RefSeq ID

Length (nt)

Assoc. CDS (aa)

v-RA

FBtr0073386

NM_078558

1305

379

Additional Transcript Data and Comments

Reported size (kB)

1.4 (northern blot)

(Fridell and Searles, 1992)

1.4 (unknown)

(Fridell et al., 1990)

Comments

External Data

Crossreferences

Polypeptide Data

Annotated Polypeptides

Name

FlyBase ID

Predicted MW (kDa)

Length (aa)

Theoretical pI

UniProt

RefSeq ID

GenBank

v-PA

FBpp0073242

44.4

379

5.72

P20351

NP_511113

AAF47978

Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments

Reported size (kDa)

Comments

External Data

Subunit Structure (UniProtKB)

Homotetramer. Dimer of dimers.

(UniProt, P20351)

Crossreferences

InterPro - A database of protein families, domains and functional sites

PDB - An information portal to biological macromolecular structures

Linkouts

Sequences Consistent with the Gene Model

Nucleotide / Polypeptide Records

UniProt

Mapped Features

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.

External Data

Crossreferences

Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.

Linkouts

Expression Data

Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

-0.73

Transcript Expression

No Assay Recorded

Stage

Tissue/Position (including subcellular localization)

Reference

adult stage

(Pret and Searles, 1991)

in situ

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage 13 -- 16

embryonic head epidermis

(Fisher et al., 2012)

embryonic/larval fat body

(Fisher et al., 2012)

northern blot

Stage

Tissue/Position (including subcellular localization)

Reference

embryonic stage -- adult stage

(Fridell and Searles, 1992)

Additional Descriptive Data

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.

(Fridell and Searles, 1992)

v transcripts are expressed at about 5% of the level of wild type in the v¹ mutant.

(Pret and Searles, 1991)

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 v^k transcripts in a su(s)⁶ v^k 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.

(Pret and Searles, 1991)

Marker for

Subcellular Localization

CV Term

Polypeptide Expression

Additional Descriptive Data

Marker for

Subcellular Localization

CV Term

Evidence

References

Expression Deduced from Reporters

High-Throughput Expression Data

Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\v in JBrowse

RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region

View exonic expression by developmental stage for Dmel\v

View exonic expression by tissue for Dmel\v

Bulk Downloads

RNA-Seq RPKM values for all genes

Reference

See Gelbart and Emmert, 2013 for analysis details and data files for all genes.

Developmental Proteome: Life Cycle

Developmental Proteome: Embryogenesis

External Data and Images

Linkouts

BDGP expression data - Patterns of gene expression in Drosophila embryogenesis

FBgn0003965

DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species

32026/tissue=All

EMBL-EBI Single Cell Expression Atlas - Single cell expression across species

FBgn0003965

FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array

FBgn0003965

FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data

FBgn0003965

Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns

CG2155

Flygut - An atlas of the Drosophila adult midgut

FBgn0003965

Images

FlyExpress - Embryonic expression images (BDGP data)

Show all FlyExpress processed images for Dmel\v

Stages(s) 1-3
Stages(s) 13-16

FlyBase Wiki

Image Based Resources

Alleles, Insertions, Transgenic Constructs, and Aberrations

Classical and Insertion Alleles ( 762 )

For All Classical and Insertion Alleles Show

Other relevant insertions

Transgenic Constructs ( 24 )

For All Alleles Carried on Transgenic Constructs Show

Transgenic constructs containing/affecting coding region of v

Transgenic constructs containing regulatory region of v

Aberrations (Deficiencies and Duplications) ( 138 )

Inferred from experimentation ( 138 )

Gene duplicated in

Dp(1;2)A124

Dp(1;2)v⁺63i

(Barbash et al., 2000, Zhang et al., 1999, Zhimulev et al., 1987, Eeken et al., 1985, Kramers et al., 1983, Lefevre, 1981, Zhimulev et al., 1981, Lefevre, 1969)

Dp(1;2)v⁺65b

(Zhimulev et al., 1987, Eeken et al., 1985, Geer et al., 1983, Kramers et al., 1983, Lefevre, 1981, Lefevre, 1969)

Dp(1;2)v⁺75d

(Barbash et al., 2000, Zhang et al., 1999, Eeken et al., 1985, Geer et al., 1983)

Dp(1;3)DC232

(Popodi et al., 2010-, Venken et al., 2010)

Dp(1;3)ras^v

Dp(1;3)v⁺74c

(Zhang et al., 1999, Eeken et al., 1985)

Dp(1;Y)v⁺y⁺

(Zhang et al., 1999, Zhimulev et al., 1987, Geer et al., 1983, Kramers et al., 1983, Zhimulev et al., 1981)

Dp(1;Y)v⁺y⁺U15

(Zhimulev et al., 1987)

Dp(1;Y)y⁺v⁺#3

(Eeken et al., 1985, Mortin and Kaufman, 1982, Lefevre, 1971)

Dp(1;Y)y⁺v⁺Bar^S#1

Dp(1;Y)y⁺v⁺Bar^S#2

Dp(1;Y)y⁺v⁺Bar^S#3

(Schalet, 1969)

Gene not disrupted in

Df(1)59D3

(Zhimulev et al., 1987)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Patterson, 1932)

(Barbash et al., 2000, Zhang et al., 1999)

Df(1)C52

(Barbash et al., 2000)

Df(1)HC133

(Barbash et al., 2000, Zhang et al., 1999, Zhimulev et al., 1987, Zhimulev et al., 1981)

Df(1)HF368

(Eeken et al., 1985)

Df(1)HM456

(Kramers et al., 1983)

Df(1)KA7

(Zhimulev et al., 1987, Geer et al., 1983, Zhimulev et al., 1981)

Df(1)m259-4

(Eeken et al., 1985)

Df(1)N71

(Zhimulev et al., 1987, Eeken et al., 1985, Geer et al., 1983, Zhimulev et al., 1981)

Df(1)N110

(Barbash et al., 2000, Zhang et al., 1999)

Df(1)RA37

(Kozlova et al., 1994, Pokholkova et al., 1991, Zhimulev et al., 1987, Geer et al., 1983, Kramers et al., 1983, Zhimulev et al., 1981)

Df(1)ras59

(Zhang et al., 1999)

Df(1)ras203

(Barbash et al., 2000, Zhang et al., 1999)

Df(1)ras-P14

(Zhimulev et al., 1987, Zhimulev et al., 1981)

Df(1)ras-TM5

(Zhang et al., 1999)

Df(1)ras-TM6

(Zhang et al., 1999)

Df(1)RJ7

(Barbash et al., 2000, Zhang et al., 1999)

Df(1)sbr1

(Kozlova et al., 1994, Zhimulev et al., 1987, Zhimulev et al., 1981)

Df(1)sbr10

(Zhimulev et al., 1987, Zhimulev et al., 1981, Zhimulev et al., 1981)

Df(1)sev-P1

(Kozlova et al., 1994)

In(1)AC2^LAB^R

(Barbash et al., 2000, Zhang et al., 1999)

T(1;2)ras-TM3

(Zhang et al., 1999)

T(1;2)v^267-4

Gene disrupted in

Df(1)59D3

(Kozlova et al., 1994)

Df(1)203C10

(Kozlova et al., 1994, Zhimulev et al., 1987)

Df(1)231c

(Patterson, 1932)

Df(1)428

(Nivard et al., 1996)

Df(1)508