FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Allele: Dmel\trn28.4
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General Information
Symbol
Dmel\trn28.4
Species
D. melanogaster
Name
FlyBase ID
FBal0032903
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
trn25/4
Key Links
Allele class
Nature of the Allele
Allele class
Progenitor genotype
Cytology
Description

Deletion of between 1.6kb and 1.9kb, beginning in the Ecol\lacZ gene of the progenitor insertion such that 3' P sequences are deleted, together with 1kb of 5' genomic trn DNA and up to between codons 164 and 274 of the trn open reading frame.

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

Lateral neuroblast clones in the antennal lobe that are homozygous for trn28.4 result in ectopic innervation of glomeruli that are normally not the targets of lateral projection neurons.

Compared to wild-types, the number of contact points is reduced between myopodia and growth cones in trn28.4/Df(3L)trnΔ17 mutant embryos.

Invaginating trn28.4 salivary glands often show irregular lumens.

trn28.4 homozygous embryos have motor axon guidance defects that primarily affect the ISNb and SNa nerves including truncation of ISNb prior to muscle 13, failure f the ISNb to branch from the intersegmental nerve and failure of SNa to bifurcate.

Homozygous clones in the eye disc appear normal.

Similarly to wild-type clones, trn28.4 single mutant clones display irregular boundaries.

With regards to trn28.4 mutant clones in the leg imaginal disc, the displacement rate of cells from tarsal segment 5 to to the pretarsal segment is reduced from the 95.2% in wild-type clones to 80.0% in the mutants.

trn28.4 mutant embryos show gaps in both the dorsal and lateral trunk.

trn28.4/In(3LR)C190 embryos show a block in normal somatic muscle morphogenesis, without defects in the initial specification of the muscles. Muscles LT1-4 and DT1 often have abnormal shapes and attachments.

Homozygous clones do not cause observable alterations in the wing disc.

Segmentation normal.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhancer of
Statement
Reference

trn28.4/trn[+] is an enhancer of visible | dominant phenotype of Bx1

trn28.4/trn[+] is an enhancer of visible phenotype of Bx1

NOT Enhancer of
Statement
Reference
Other
Phenotype Manifest In
Enhanced by
Suppressed by
Enhancer of
Statement
Reference

trn28.4/trn[+] is an enhancer of wing margin phenotype of Bx1

trn28.4/trn[+] is an enhancer of wing phenotype of CSN5L4032

trn28.4/trn[+] is an enhancer of wing phenotype of Bx1

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

capsDel1 trn28.4 double mutants do not exhibit an enhanced mutant R8 photoreceptor phenotype compared to capsDel1 single mutants.

Lateral neuroblast clones in the antennal lobe that are doubly homozygous for capsDel1 and trn28.4 show two types of dendrite targeting defects; loss of innervation in glomeruli that are normally targets of lateral projection neurons and gain of innervation in glomeruli that are normally not the targets of lateral projection neurons. Loss of innervation of the VA7m, VC1 and VC2 glomeruli is frequently seen in the double mutant embryos.

Invaginating capsDel1 trn28.4 salivary glands often show irregular lumens.

trn28.4 capsDel1 double mutant clones in the eye disc show subtle but consistent defects. At the clone border, there is a consistent reduction in the apical constriction of cells. This phenotype is fully penetrant, but appears more pronounced when the clone boundary is perpendicular to the morphogenetic furrow. Within the morphogenetic furrow, cells at the clone boundary are also taller than their neighbours, as their apical surfaces are elevated, disrupting the furrow. The phenotypes of relaxation of apical constriction and increase in apical-basal height of cells are non-autonomous as they are seen in both mutant and wild-type cells at the clone boundary. The range of the phenotype is only 2-3 rows of cells beyond the clone border.

trn28.4 capsDel1 double mutant clones in the third instar eye disc result in a perturbation in ommatidial spacing. This is only apparent at the boundaries between mutant and wild-type cells, where ommatidia close to these boundaries are often clearly displaced from their normal positions with no obvious change to their individual morphology. The total number of ommatidia is not affected. This phenotype is non-autonomous, with both mutant and wild-type ommatidia showing mis-positioning. At pupal stages of development, spacing defects are still seen in eye discs with trn28.4 capsDel1 double mutant clones, and fusion of neighbouring ommatidia that are abnormally close to each other is seen in about 5% of ommatidia adjacent to clone boundaries. Very occasional defects are seen in the number of cone cells.

trn28.4, caps65.2 double mutant embryos show an additive phenotype, where the sum of the gaps in the dorsal and lateral trunks seen in single mutants is close to the figure seen in the double mutants.

Expression of capsED.Scer\UAS under the control of Scer\GAL4twi.PG in trn28.4 embryos rescues the dorsal trunk defects in 47% of cases. In contrast, expression of either capsScer\UAS.cSa or capsID.Scer\UAS, under the control of Scer\GAL4twi.PG, increases the severity of the dorsal trunk formation trn28.4 phenotype.

Expression of caps::trncapsEd.trnId.Scer\UAS under the control of Scer\GAL4twi.PG rescues the tracheal defects of trn28.4 embryos. In contrast, expression of caps::trntrnEd.capsId.Scer\UAS under the control of Scer\GAL4twi.PG enhances the tracheal defects of trn28.4 embryos so that these embryos show 11.2% more dorsal trunk interruptions than trn28.4 mutants.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
References (16)