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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Nature of the Allele
Mutations Mapped to the Genome
Additional Notes
point mutation
Nucleotide change:


Reported nucleotide change:


Amino acid change:

Q163term | sc-PA

Reported amino acid change:


Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype

Originally thought to be associated with a minute deficiency (Schultz); not confirmed by molecular analysis.

Nature of the lesion

Nonsense mutation in the sc coding sequence, 162 amino acids of 345 are translated.

Point mutation that creates a stop codon within sc.

Amino acid replacement: ?163term.

Amino acid replacement: Y660term.

C669T mutation is silent. See Villares and Cabrera, 1987.

Nucleotide substitution: C669T.

Nucleotide substitution: C1143G.

Amino acid replacement: S161R.

Distal deficiency breakpoint is near the transcriptional start of the ac gene and the proximal breakpoint causes a nonsense mutation in the sc coding sequence.

Caused by aberration
Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

Approximately 5.5% of sc10-1 heterozygous flies lose their post-vertical head bristles.

Removing one copy of sc in sc10-1 heterozygous flies results in the loss of campaniform sensilla in 15% of flies.

The anterior wing margin of sc10-1 pupae males is missing chemosensory bristles and shows a small but statistically significant reduction in the number of stout bristles compared to wild-type wing margins. At the pupal stage there is an absence of chemosensory clusters but there is no significant reduction of mechanosensory precursors. However, the number of neurons that develop from the mechanosensory precursors is severely reduced in sc10-1 pupae and there is a decrease in the number of socket cells.

sc10-1 mutants show no thoracic bristles.

sc10-1 mutants show loss of the posterior supra-alar, posterior notopleural, anterior notopleural and anterior postalar thoracic bristles to varying degrees.

In the absence of ac and sc all cells in the ZNC of the developing wing arrest in G1 arrest.

Homozygous third instar larvae show a normal response to UVC radiation.

sc10-1/sisA1 female transheterozygotes have reduced viability, they are fully viable when they carry P{scsub}.

Glial cells of wing nerves are absent in adult wing and almost completely absent in the developing wing.

The nota of sc10-1 flies, which are normally devoid of bristles, develop sense organs when asehs.PB is expressed.

Developmental capacities of germ cells homozygous for this allele were studied in pole cell transplants: fertile females and males result.

Like sc3 but more extreme; most extreme viable sc allele. Viability low. RK2A.

Neither macrochaetes nor microchaetes form on the notum: no sensory mother cells develope. BrdU labelling shows that arrangement of mitotically quiescent cells is wild type.

sc is expressed in a similar pattern as wild type. sc mRNA is absent from the sites where expression is originally driven by ac.

Flies (mutant for ac3 as well as sc10-1) show an extreme bristle phenotype.

Dorsal and ventral rows of chemosensory organs are absent in pupal wings.

80% of female scsisB-1/sc10-1 embryos die. All female scsisB-1/sc10-1 embryos heterozygous for Sxlf1 die. Approximately 85% of homozygous female sc10-1 embryos die. This lethality is completely rescued by one copy of SxlM1. These flies survive to adulthood and show an extreme sc10-1 phenotype. Female embryos heterozygous for sc10-1 and deficient for one copy of sisA show 30% lethality.

The basitarsi of the second legs are reduced in width and length and have no bristles. The 8.5p sensillum is missing.

Lack sense organs on the notum and other areas.

Flies have extreme ac and sc phenotypes and are devoid of almost all sensory organs.

The adults that occasionally emerge from the pupal case lack all microchaetae and macrochaetae, except those of the eye and wing margin. The phenotype very similar to that shown by the deficiency Df(1)sc19 that lacks the sc locus.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Enhanced by

sc10-1 has head bristle phenotype, enhanceable by Act5CEY11969

sc10-1 has head bristle phenotype, enhanceable by da[+]/da10

sc10-1 has medial triple row phenotype, enhanceable by sensE2/sens[+]

sc10-1 has eo neuron phenotype, enhanceable by sensE2/sens[+]

sc10-1 has tormogen cell phenotype, enhanceable by sensE2/sens[+]

sc10-1 has anterior postalar bristle phenotype, enhanceable by accami/ac[+]

NOT Enhanced by

sc10-1 has head bristle phenotype, non-enhanceable by Act5CG0010/Act5C[+]

Suppressed by
NOT suppressed by

sc10-1 has phenotype, non-suppressible by su(Hw)2

Enhancer of

sc[+]/sc10-1 is an enhancer of head bristle phenotype of da10

Suppressor of

sc10-1 is a suppressor | partially of macrochaeta | ectopic & antenna phenotype of amos1/Df(2L)M36F-S6

Additional Comments
Genetic Interactions

Approximately 95% of sc10-1/+; da10/+ trans-heterozygous flies exhibit missing post-vertical head bristles.

Knockdown of Act5C through expression of Act5CGD1351 under the control of Scer\GAL4dpp.blk1 results in a dramatic increase in the percentage of sc10-1 flies missing campaniform sensilla. Likewise, knockdown of Act5CGD1351 by Scer\GAL4pnr-MD237 in the sc10-1/+ fly notum markedly increased the percentage of flies missing anterior dorso-central mechano-sensory macrochaetae from 30% to 87%, and missing posterior dorso-central macrochaetae from 0% to 24%.

sc10-1/+; Act5CEY11969/+ double heterozygotes exhibit some loss of post-vertical head bristles in 45% of flies.

The percentage of the double heterozygous sc10-1/+; +/+; Act5CG0010/+ flies missing post-vertical head bristles are no significantly different or only mildly increased compared with sc10-1/+ flies.

sc10-1; sensE2/+ flies show a severe loss of stout bristles at the wing margin in comparison to sc10-1 single mutants, which show a small loss of these bristles. At the pupal level the sc10-1; sensE2/+ double mutants are almost completely lacking the neurons that should have developed from the mechanosensory precursors; this is an enhancement of the reduced number of neurons seen in sc10-1 single mutant pupae. The double mutants also show a greater loss of socket cells than the single mutants.

Expressing one copy of sens+t11 in a sc10-1 background restores the number of stout bristles to near wild-type numbers.

Expression of daScer\UAS.cGa in the thorax, under the control of Scer\GAL4Eq1, leads to the generation of numerous bristles on the thorax of sc10-1 mutants. These mutants have no thoracic bristles without the transgene expression.

Expression of sensScer\UAS.cNa in the thorax, under the control of Scer\GAL4Eq1, leads to the generation of bristles on the thorax of sc10-1 mutants. The amount of bristles generated by sensScer\UAS.cNa is insertion-dependent; the weak P{UAS-sens.N}C6 insertion leads to the presence of only a few bristles, while the strong P{UAS-sens.N}C5 insertion generates more bristles.

Coexpression of daScer\UAS.cGa and sensScer\UAS.cNa in the thorax, under the control of Scer\GAL4Eq1, leads to the generation of multiple bristles on the thorax of sc10-1 mutants; these bristles are present at a much greater density than those on wild-type thoraces or indeed the density produced by expressing either daScer\UAS.cGa or sensScer\UAS.cNa alone.

sc10-1/+, accami/+ mutants experience a greater loss of the posterior supra-alar, posterior notopleural, anterior notopleural and anterior postalar bristles than sc10-1 single mutants.

Does not interact with Sxldlf. Females doubly heterozygous for sc10-1 and either fl(1)3535 or fl(1)3546 show reduced viability compared to single heterozygous females. Females doubly heterozygous for l(1)4343 and sc10-1 show a slight reduction in viability compared to single heterozygous females.

Xenogenetic Interactions

Expressing BacA\p35Scer\UAS.cHa in the wing margin, under the control of Scer\GAL4C96, in a sc10-1 background rescues the stout bristle loss seen in sc10-1 mutants. At the pupal level, BacA\p35Scer\UAS.cHa, expression also rescues the loss of neurons seen in the single mutants. However, this expression also results in the appearance of ectopic neurons at the posterior wing margin, a place where such neurons are not found in wild type. These neurons send out axons which merge with the marginal nerve that runs along the anterior wing margin towards the thorax.

Complementation and Rescue Data
Partially rescued by

sc10-1 is partially rescued by sc+mDC

sc10-1 is partially rescued by sc+mDC.SMC


In female D.simulans/D.melanogaster hybrids that carry In(1)ac3 and sc10-1, the bristle phenotype at 18oC is no different to wild-type D.simulans/D.melanogaster hybrids. At 25oC a bristle phenotype is seen in simulans/D.melanogaster hybrids that carry In(1)ac3 and sc10-1 that is not as strong as wild-type D.simulans/D.melanogaster hybrids.

Bristle phenotype not rescued by sc+ transgenes.

Expression of schs.PR during the first two hours of development rescues female scsisB-1/sc10-1 embryos.

Images (0)
Stocks (4)
Notes on Origin

Sturtevant, 1930.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
References (49)