FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Allele: Dmel\Nact.sev
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General Information
Symbol
Dmel\Nact.sev
Species
D. melanogaster
Name
activated
FlyBase ID
FBal0029959
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
sev-Nact, sev-N*, sev-NΔecd, sev-notchAct, sev.N*
Key Links
Transgenic product class
Nature of the Allele
Transgenic product class
Progenitor genotype
Carried in construct
Cytology
Description

Activated intracellular N under sev gene control.

Construct: N gene contains a deletion from 948bp to 5873bp, expression is driven by a sev promoter.

Allele components
Component
Use(s)
Regulatory region(s)
Encoded product / tool
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

In a wild-type background, Nact.sev causes R1/R6 cells to differentiate as R7 cells.

Flies carrying Nact.sev have a rough eye phenotype and extra R7 photoreceptor cells in the ommatidia.

Nact.sev expression causes development of supernumerary R7 photoreceptor cells in expense of R1/R6 photoreceptor fate.

Nact.sev expression in svp1 mutant R1/R6 cells (generated using WGMR.PG) results in all cells transforming to a R7 cell fate, as opposed to either an R7 or R8 fate as is seen in cells that are only mutant for svp1.

The eyes if Nact.sev flies have many symmetrical ommatidia. Some of these have a pair of R4s in place of an R3/R4 pair, while others have an R7 pair in place of an R1/R6 pair.

Most ommatidia are symmetrical in flies expressing Nact.sev, due to the presence of two R4 cells. Photoreceptor cells R1 and R6 also appear to be missing.

Most Nact.sev mosaic ommatidia have abnormal photoreceptor complements. The R7 cell is insensitive to the presence of Nact.sev. In contrast virtually no normally composed ommatidia in which either R1 or R6 carry Nact.sev are observed.

Expression of Nact.sev produces adult eyes containing ommatidia with 4-5 outer cells and up to three R7-like cells. Some ommatidia have only one or two R7 photoreceptors.

Flies expressing Nact.sev develop symmetrical ommatidia (more than 69.5% of ommatidia have this phenotype). The ommatidia have only 4 outer photoreceptor cells (R4/R4/R2/R5 based on molecular markers).

Flies expressing Nact.sev develop many symmetrical ommatidial clusters showing the R4/R4 phenotype. This phenotype is not affected by dsh1. Flies expressing Nact.sev also show loss and transformation of outer photoreceptors R1 to R6. In ommatidia that are mosaic in the R3/R4 photoreceptors, the Nact.sev cell always adopts the R4 fate. This can lead to polarity reversals.

Rough eye phenotype is observed. Expression in eye discs causes ommatidial clusters to contain 5 instead of 4 cone cells, fate of the R7 cells changes to a cone cell. Expression in R3 and R4 precursors results in transformation of these cells into two R7 cells. Phenotype is enhanced by expression of NANK.sev.

Moderate roughening of the eye surface: many ommatidia display a 'partial lens' morphology.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement
Reference

Nact.sev has visible phenotype, enhanceable by dx1

Nact.sev has visible phenotype, enhanceable by Delta5F

Nact.sev has visible phenotype, enhanceable by Su(H)T4

NOT Enhanced by
Statement
Reference
Suppressed by
Statement
Reference

Nact.sev has visible phenotype, suppressible by Su(H)IB115

NOT suppressed by
Statement
Reference
Suppressor of
Statement
Reference
Phenotype Manifest In
Enhanced by
Statement
Reference

Nact.sev has phenotype, enhanceable by DeltaeAA5

Nact.sev has phenotype, enhanceable by DeltaeAB2

Nact.sev has phenotype, enhanceable by DeltaeAC2

Nact.sev has phenotype, enhanceable by DeltaeAI3

Nact.sev has phenotype, enhanceable by DeltaeAI9

Nact.sev has phenotype, enhanceable by DeltaeAK2

Nact.sev has phenotype, enhanceable by DeltaeAL3

Nact.sev has phenotype, enhanceable by DeltaeAN13

Nact.sev has phenotype, enhanceable by DeltaeAN9

Nact.sev has phenotype, enhanceable by DeltaeAR3

Nact.sev has phenotype, enhanceable by DeltaeAU2

Nact.sev has phenotype, enhanceable by DeltaeAU4

Nact.sev has phenotype, enhanceable by DeltaeAU8

Nact.sev has phenotype, enhanceable by DeltaeAV12

Nact.sev has phenotype, enhanceable by DeltaeAY2

Nact.sev has phenotype, enhanceable by DeltaeAZ18

Nact.sev has phenotype, enhanceable by DeltaeAZ1

Nact.sev has phenotype, enhanceable by DeltaeM4

Nact.sev has phenotype, enhanceable by DeltaeM9

Nact.sev has phenotype, enhanceable by DeltaeP10

Nact.sev has phenotype, enhanceable by DeltaeQ3

Nact.sev has phenotype, enhanceable by SeAA2

Nact.sev has phenotype, enhanceable by SeAD7

Nact.sev has phenotype, enhanceable by SeAG4

Nact.sev has phenotype, enhanceable by SeAG5

Nact.sev has phenotype, enhanceable by SeAN5

Nact.sev has phenotype, enhanceable by SeAO3

Nact.sev has phenotype, enhanceable by SeAQ3

Nact.sev has phenotype, enhanceable by SeO7

Nact.sev has phenotype, enhanceable by SoseN6

Nact.sev has phenotype, enhanceable by Su(H)eBC11

Nact.sev has phenotype, enhanceable by anon-XIIIeAH7

Nact.sev has phenotype, enhanceable by anon-XIIIeAV9

Nact.sev has phenotype, enhanceable by anon-XXeAK12

Nact.sev has phenotype, enhanceable by anon-XXeAV4

Nact.sev has phenotype, enhanceable by dxeAN1

Nact.sev has phenotype, enhanceable by kiseB15

Nact.sev has phenotype, enhanceable by kiseBA8

Nact.sev has phenotype, enhanceable by kiseBD10

Nact.sev has phenotype, enhanceable by kiseI7

Nact.sev has phenotype, enhanceable by lolaeAK4

Nact.sev has phenotype, enhanceable by mameA1

Nact.sev has phenotype, enhanceable by mameA6

Nact.sev has phenotype, enhanceable by mameAO1

Nact.sev has phenotype, enhanceable by mngeD9

Nact.sev has phenotype, enhanceable by pnteAL13

Nact.sev has phenotype, enhanceable by pnteAS7a

Nact.sev has phenotype, enhanceable by pnteT13

NOT Enhanced by
Statement
Reference

Nact.sev has phenotype, non-enhanceable by lilliXS407

Nact.sev has phenotype, non-enhanceable by lilliXS575

Nact.sev has phenotype, non-enhanceable by lillis35

Nact.sev has phenotype, non-enhanceable by rinunspecified

Suppressed by
Statement
Reference
NOT suppressed by
Statement
Reference
Other
Additional Comments
Genetic Interactions
Statement
Reference

In a sev14; Nact.sev double mutant background, R1/R6 cells differentiate as cone cells, and, in the adult eyes only large rhabdomere cells are evident in the outer regions (R7 level) of the eye. Thus, removal of sev from Nact.sev ommatidia presents the specification of the R1/R6 cells as photoreceptors.

The rough eye and extra R7 photoreceptor cell phenotypes caused by Nact.sev are not suppressed by expression of Socs36EScer\UAS.P\T.cCa under the control of Scer\GAL4hs.2sev.

emcAP6 suppresses the Nact.sev induced development of supernumerary R7 photoreceptor cells in ommatidia.

Expression of AntpScer\UAS.cBa and Nact.sev under the control of Scer\GAL4ey.PH induces the ectopic outgrowth of T2-specific appendages (wings and legs) on the adult head the transformation of the anntenna into leg is not complete, owing to the fact that Scer\GAL4ey.PH is not expressed in the entire antennal disc.

Approximately 20% of Scer\GAL4ey.PH; Nact.sev; AntpAAAA.Scer\UAS flies exhibit antenna-to-leg transformation, while none of these flies show eye-to-wing transformation. Legs induced in this fashion exhibit second leg identity, growing tibial apical bristles.

Misexpression of Nact.sev with UbxScer\UAS.cPa under the control of Scer\GAL4ey.PH does not induced any ectopic wing outgrowth in the eye, but exhibits antenna-to-leg transformation.

Misexpression of Nact.sev with AntpK50.Scer\UAS under the control of Scer\GAL4ey.PH results in an arista-to-tarsus transformation phenotype. These mutants exhibit some antenna-to-leg transformation but fail to induce ectopic wing tissue in the eye.

Co-expression of exdScer\UAS.cGa in combination with AntpScer\UAS.cBa or AntpAAAA.Scer\UAS in the presence of Nact.sev all under the control of Scer\GAL4ey.PH results in approximately 2% of flies exhibiting wing structures in the eye region, compared to around 40% when exdScer\UAS.cGa is absent. Only 3% of these flies show antenna-to-leg transformation compared with 28% without exdScer\UAS.cGa. The presence of exdScer\UAS.cGa also inhibits antenna-to-leg transformation induced by AntpAAAA.Scer\UAS from 19% to 4.5% (in a Nact.sev and Scer\GAL4ey.PH background).

The planar cell polarity phenotype displayed by the eyes of Nact.sev; stanScer\UAS.cUa ; Scer\GAL4sev.PM181 flies is distinct from that of stanScer\UAS.cUa ; Scer\GAL4sev.PM181 flies, but indistinguishable from that of Nact.sev flies.

The increased level of apoptosis in eye discs of animals carrying two copies of Psn+14.Scer\UAS expressed under the control of Scer\GAL4GMR.PF is strongly reduced by the expression of Nact.sev.

Second site dominant suppressors reduce the external roughness of the eye, in addition to causing the overall eye shape to become both rounder and larger, and less refractile. Second site dominant enhancers increase the roughness of the eye, eye shape is smaller and flatter and eyes appear more glossy or shiny.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Comments
Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
Reported As
Symbol Synonym
Name Synonyms
activated
Secondary FlyBase IDs
    References (31)