FB2026_02 , released June 18, 2026
Allele: Dmel\tra2B
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General Information
Symbol
Dmel\tra2B
Species
D. melanogaster
Name
FlyBase ID
FBal0017022
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
tra-2B, tra-2B
Key Links
Genomic Maps

Nature of the Allele
Progenitor genotype
Cytology
Description

Nonsense codon within the RRM that truncates translation of all three tra2 isoforms deleting the RNP1 region of the RRM as well as the entire essential RS2 domain.

Amino acid replacement: ??term.

Nucleotide substitution: C?T.

Mutation is within exon 5, which creates an in-frame premature stop codon that is expected to cause truncation of the polypeptides encoded by each of the major tra2 transcripts at a position within the putative RNA-binding domain and 155 amino acids upstream from their shared carboxyl terminus.

Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Nucleotide change:

C14603232T

Amino acid change:

Q110term | tra2-PA; Q110term | tra2-PB; Q72term | tra2-PC; Q72term | tra2-PD; Q25term | tra2-PE; Q110term | tra2-PF; Q110term | tra2-PG

Comment:

altered sequence presented in Figure 4 of FBrf0054067; introduces stop codon in the polypeptides encoded by each of the major tra2 transcripts, 155 amino acids upstream from their shared carboxyl terminus

Variant Molecular Consequences
Associated Sequence Data
DNA sequence
Protein sequence
 
Expression Data
Reporter Expression
Additional Information
Statement
Reference
 
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 0 )
Disease
Interaction
References
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
 
Disease-implicated variant(s)
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Both tra2B/tra2ts1 transheterozygotes shifted from 18[o]C into 29[o]C upon reaching adulthood and tra2B/Df(2R)trix transheterozygotes do not show significant mitotic index differences in female and male adult posterior midguts, as compared to controls.

Adult XX tra2B/Df(2R)trix pseudomales have a sex comb on the first leg, which contains a similar number of bristles to that of their XY brothers.

XX ; tra2B/Df(2R)trix animals develop as pseudomales.

About 10% of 2X tra2B/Df(2R)trix males have a well developed germline with advanced primary spermatocytes, spermatids or sperm. The remaining animals have gonads containing mostly debris.

Heterozygous tra2B/+ adults have normal sexual differentiation.

XX homozygotes are sterile, develop into somatic males, and develop sex combs. XY homozygotes are sterile.

Individuals are transformed into males. Heat induced expression of P{hs-htra-2α} causes female sexual differentiation.

Homozygous chromosomal females appear male, with well developed sex combs.

No more than 26% of XX tra2 mutant pseudomales produce gonads with the most severe group 1 pseudotestes phenotype. The remaining pseudomales have a less severe phenotype, with viable germ cells. otu10 and Df(1)otu-PΔ1 cause an increase in severity of this phenotype: over 70% of the resulting gonads were of group 1.

Females exhibit segment spanning muscles in the fifth abdominal segment indicative of a transformation to the male specific phenotype. Somatic development of males is unaffected.

tra2B/tra2B identical to tra2B/tra2 or to tra2B/Df(2R)L4 (Baker and Ridge, 1980).

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
NOT suppressed by
Statement
Reference
Other
Phenotype Manifest In
Enhanced by
Statement
Reference

tra2B has phenotype, enhanceable by B52ED

Suppressed by
Statement
Reference
NOT suppressed by
Statement
Reference

tra2B has phenotype, non-suppressible by snf1

tra2B has phenotype, non-suppressible by otuunspecified

tra2B has phenotype, non-suppressible by B52::tra2A.N.Tag:FLAG

tra2B has phenotype, non-suppressible by B52::tra2B.N.Tag:FLAG

tra2B has phenotype, non-suppressible by B52::tra2C.Tag:FLAG

tra2B has phenotype, non-suppressible by B52::tra2N.Tag:FLAG

Enhancer of
Statement
Reference
Suppressor of
NOT Suppressor of
Other
Additional Comments
Genetic Interactions
Statement
Reference

XX tra21/tra2B ; bonS043420/bonS043420 animals, that are genetically female (XX) but phenotypically male are viable.

The frequency of germline development (including spermatogenesis) in 2X tra2B/Df(2R)trix males is unaffected by either snf1 or otuunspecified. 2X tra2B/Df(2R)trix males that are also carrying ovounspecified do not show any evidence of germ cells.

XX ; tra2B/+ adults that are also carrying Doaunspecified/Doa7 are clearly intersexual with respect to the number or morphology of sex combs.

fru1 tra2B double mutants have an abnormal Muscle of Lawrence, like that of fru1 males.

tra2B/tra2+; traunspecified/tra+ female double heterozygotes are sometimes intersexual, particularly at high temperatures. Presence of B52ED enhances the frequency of intersexuality.

Xenogenetic Interactions
Statement
Reference

The number of bristles seen in the sex comb on the first leg in XX tra2B/Df(2R)trix pseudomales is significantly reduced by expression of Zzzz\Aobl-tra2Scer\UAS.cSa under the control of Scer\GAL4rn-GAL4 (the animals also contain the temperature sensitive Scer\GAL80ts.αTub84B allele which is used to repress Scer\GAL4 expression until after hatching by raising the animals initially at 18[o]C and then transferring them to 25[o]C after hatching).

Expression of Zzzz\trafl.Scer\UAS in a tra2B/Df(2R)trix background, under the control of Scer\GAL4da.G32 does not affect male morphology, indicating the endogenous tra2 protein is necessary in female development. Reducing, but not removing tra2, through expression of Zzzz\trafl.Scer\UAS in a tra2B/+ background, under the control of Scer\GAL4arm.PS leads to a significant reduction in the size of the female genital structures as well as a significant increase in the size of the male genital structures.

The mutant phenotype of XX ; tra2B/Df(2R)trix animals is not rescued by Ccap\trahs.PP.

Female differentiation is variably restored in XX homozygotes carrying Dvir\tra2tCa. Fertility can be restored in XY homozygotes by a single copy of Dvir\tra2tCa.

Complementation and Rescue Data
Images (0)
Mutant
Wild-type
Stocks (4)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (33)