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General Information
Symbol
Dmel\Scr
Species
D. melanogaster
Name
Sex combs reduced
Annotation Symbol
CG1030
Feature Type
FlyBase ID
FBgn0003339
Gene Model Status
Stock Availability
Gene Snapshot
Sex combs reduced (Scr) is a member of the Antennapedia complex (ANT-C), one of two Hox gene complexes. Products of members of the ANT-C control the identity of segments that contribute to the head and the anterior thorax. Scr is expressed in the embryonic labial and first thoracic segments. In the absence of its expression the first prothoracic segment is transformed to a second mesothoracic identity and the labial palps to maxillary. [Date last reviewed: 2019-03-14]
Also Known As
Msc, Multiple sex comb
Key Links
Genomic Location
Cytogenetic map
Sequence location
3R:6,823,120..6,849,981 [-]
Recombination map
3-48
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
Belongs to the Antp homeobox family. Deformed subfamily. (P09077)
Summaries
Gene Group (FlyBase)
ANTENNAPEDIA COMPLEX -
The Antennapedia complex (ANT-C) is one of two Hox gene complexes. Hox genes encode homeodomain transcription factors. ANT-C controls the identity of segments that contribute to the head and the anterior thorax. ANT-C homeotic genes show colinearity in their expression patterns with the exception of pb. (Adapted from FBrf0190304).
HOX-LIKE HOMEOBOX TRANSCRIPTION FACTORS -
HOX-like (HOXL) homeobox transcription factors are sequence-specific DNA binding proteins that regulate transcription. They encompass transcription factors encoded by the Hox genes of the Antennapedia and the Bithorax gene complexes and genes closely related in sequence. HOXL transcription factors are major regulators of animal development. (Adapted from FBrf0232555).
Protein Function (UniProtKB)
Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Controls the segmental transformation of the first to the second thoracic segment (prothorax to mesothorax) and of the labial palps into maxillary palps. In embryo, required for fusion of labial lobes and development of the T1 denticle belt. In adult, expression in the head is necessary for proper development of the labium. In the first thoracic segment of the adult, required for proper development of the sex comb and to suppress improper prothoracic wing development.
(UniProt, P09077)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
Scr: Sex combs reduced
Null mutations at the locus result in embryonic lethality. Animals die at the end of embryogenesis and show evidence of homeotic transformation in the cuticle derived from the labial and first thoracic segments. The first thorax is transformed to a second thoracic identity and the labial segment toward maxillary. This latter phenotype is seen as a duplication of the maxillary sense organs and the cirri. Deletions of the locus as well as null alleles also produce a dominant phenotype most clearly seen in males as a reduction in the number of sex-comb teeth. This reduction is indicative of a partial transformation of first leg to second, a conclusion borne out by the recovery of hypomorphic alleles of the locus which as hemizygotes allow survival to the adult stage and have no obvious effect in the embryo. These survivors show a complete transformation of ventral prothorax to mesothorax including the presence of stenopleural bristles on the propleurae; they also show an apparent transformation of the dorsal prothorax toward a mesothoracic identity. In addition to these thoracic transformations, the labial palps are transformed toward a maxillary palp morphology. All of these adult transformations can also been seen in X-ray-induced somatic clones of Scr- cells. Thus Scr activity is needed for proper segmental identity in both the embryo and adult in the anterior-most segment of the thorax and the posterior-most metamere of the head. In the absence of Scr product these two segments are transformed divergently to the identity of the next most posterior and anterior metamere respectively. The only other homeotic mutation to produce such a divergent homeosis is pb, which appears to act similarly in the adjacent maxillary and labial segments of the adult head. In addition to these loss-of-function mutations there are several gain-of-function dominant alleles. All result in a similar phenotype in adults, most clearly seen in males as the production of sex combs on the second and third thoracic legs. Additionally, strong alleles of this type (ScrScxW, ScrScxP, and ScrScxS) show the loss of sternopleural bristles indicative of a more complete transformation of mesothorax to prothorax. All of these dominants are associated with genomic rearrangements and with the exception of ScrScxS act as recessive lethals (ScrMsc, ScrScxT1, ScrScxT2, and ScrScxP) or semilethals (ScrScxW and ScrScxT3) at the locus. Examination of animals carrying these lesions at the end of embryogenesis as heterozygotes with a normal chromosome or hemizygotes reveals no evidence of the gain-of-function transformation of T2 and T3 -> T1, only the loss-of-function phenotypes described above. These phenotypic observations have been extended by showing that Scr protein is accumulated ectopically in the second and third leg imaginal discs in dominant gain-of-function genotypes but not in the second and third thoracic segments at any point in embryogenesis. Thus it appears that the spatial pattern of Scr expression is differentially regulated at these two times. Genetic analyses have shown that at least one difference lies in Scr imaginal expression being subject to a transvection-like effect. The gain-of-function lesions cause or allow the ectopic expression of the structural gene on the trans- rather than the cis-coupled transcription unit. This is most clearly seen in the case of ScrScxT1, which is broken within the transcribed portion of Scr and is therefore incapable of making a functional gene product. Scr mRNA is first detected in embryos in early gastrulae in a band of cells just posterior to the cephalic furrow. Protein is not detected at this time but later during germ-band elongation; it is found in the region of the labial lobe. Subsequently, during germ-band retraction, RNA and protein are detected in the first thoracic segment with the highest concentration at the anterior border of this segment. RNA and protein are also detected in the subesophageal region of the CNS in the labial ganglion and in mesodermal cells associated with the anterior midgut. As head involution proceeds, the Scr-expressing cells of the labial segment are carried inside where they are found associated with the pharynx and the mouthparts at the end of embryogenesis. In the third larval instar, protein is found in the prothoracic leg discs, the dorsal prothoracic discs, the labial discs, and a small group of cells in the stalk of the antennal portion of the eye-antennal disc where it attaches to the mouthparts. In addition to this disc expression, Scr protein is accumulated in the subesophageal region of the CNS. This spatial pattern of expression in the epidermis is consistant with the spectrum of defects seen in Scr- animals and clones.
Summary (Interactive Fly)
transcription factor - homeodomain - Antp class - required for labial and first thoracic segment development - expressed in the embryonic labial and first thoracic segments - in the absence of Scr expression the first prothoracic segment is transformed to a second mesothoracic identity and the labial palps to maxillary
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
3

Please see the GBrowse view of Dmel\Scr or the JBrowse view of Dmel\Scr 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
Comments on Gene Model
Gene model reviewed during 5.50
gene_with_stop_codon_read_through ; SO:0000697
Double stop-codon suppression (UAG, UAG) postulated; FBrf0234051 and FlyBase analysis.
Gene model reviewed during 6.25
Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0081657
4140
417
FBtr0081658
2585
417
FBtr0474171
4140
508
FBtr0474172
4140
427
Additional Transcript Data and Comments
Reported size (kB)
4.2 (longest cDNA)
3.9 (northern blot)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0081163
44.3
417
9.16
FBpp0089393
44.3
417
9.16
FBpp0423170
52.9
508
8.43
FBpp0423171
45.3
427
8.98
Polypeptides with Identical Sequences

The group(s) of polypeptides indicated below share identical sequence to each other.

417 aa isoforms: Scr-PA, Scr-PB
Additional Polypeptide Data and Comments
Reported size (kDa)
417 (aa); 44 (kD predicted)
Comments
External Data
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Scr using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Gene Ontology (12 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518650
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN002518650
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN002518650
(assigned by GO_Central )
Biological Process (6 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from mutant phenotype
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518650
(assigned by GO_Central )
traceable author statement
non-traceable author statement
traceable author statement
Cellular Component (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518650
(assigned by GO_Central )
Expression Data
Expression Summary Ribbons
Colored tiles in ribbon indicate that expression data has been curated by FlyBase for that anatomical location. Colorless tiles indicate that there is no curated data for that location.
For complete stage-specific expression data, view the modENCODE Development RNA-Seq section under High-Throughput Expression below.
Transcript Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
dorsal ectoderm anlage

Comment: anlage in statu nascendi

ventral ectoderm anlage

Comment: anlage in statu nascendi

northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
radioisotope in situ
Stage
Tissue/Position (including subcellular localization)
Reference
cephalic furrow | posterior to

Comment: reference states 2.5-3.1 hr AEL

ventral nerve cord | restricted

Comment: reference states >10.2-11.2 hr AEL

Additional Descriptive Data
In extended germ band stage embryos, pre-mRNA transcripts of Scr can be found in both the labial segment and, less abundantly, in the anterior half of the prothoracic segment. In contrast, Scr protein expression is limited to the labial segment.
Scr is ectopically expressed in parasegment 3 and the anterior part of parasegment 4 in tsh Antp double mutants. The same pattern is observed in embryos lacking tsh, Antp, Ubx, abd-A, and Abd-B.
Scr is normally expressed in the labial segment and the dorsolateral part of the prothoracic segment after germband elongation. In a tsh mutant, Scr is ectopically expressed in the ventral ectoderm of the prothorax.
During embryogenesis, Scr transcript is first detected at the start of gastrulation in a 3-4 cell wide band just posterior to the cephalic furrow. At the extended germ band stage, Scr transcript is detected in both layers of the ectoderm of the labial segment, as well as in the anterior portion of the outer ectodermal layer and the mesoderm of the first thoracic segment. This pattern is still detected at the start of germ band contraction, but additional hybridization is detected throughout the outer ectodermal layer of the first th racic segment. After the start of head involution, Scr transcript accumulates in a pattern similar to that of Scr protein, with grains detected in a subset of the ventral nerve cord, wall of the anterior midgut, and continued epidermal labeling in labial and first thoracic segments.
In the cellular blastoderm, Scr transcripts are located in a band 3-4 cells wide located adjacent to the band of Dfd expression. The band of expression is present only in lateral and dorsal parts of the embryo. Lower levels of expression are observed in six additional bands spaced at double segment intervals posterior to the main band of expresssion. Using en as a marker, the main band of Scr expression was localized to parasegment 2. The more posterior expression is thought to correspond to the remaining even-numbered parasegments. In stages 9-10, Scr transcripts accumulate in ectodermal cells of PS2 but not in the overlying mesoderm but do accumulate in mesoderm overlying PS3. By stage 11, the entire labial bud expresses Scr. There is a gradient of Scr expression across PS3 with the strongest expression in the area closest to PS2. Scr expression is also seen in neural derivatives of PS3 and at a lower level in PS6-12. Scr is expressed in the mesoderm of PS3 at stage 11 in both somatic and visceral components. Expression is seen at stage 12 in all myoblasts of T1 and in a portion of the mesoderm surrounding the anterior midgut. This pattern persists until hatching. Later some expression is seen in visceral mesoderm of the posterior midgut. In larvae, exrpession is observed in the labial, and dorsal and ventral prothoracic discs. In addition, some cells of the wing and second leg disc express Scr. Their position suggests that they are adepithelial cells.
Scr transcripts accumulate ventrally in the labial and prothoracic segments in germband extended embryos. Following germ band retraction, signal is detected in the nervous system, particularly in the suboesophageal and prothoracic ganglion, as well as in the pharynx.
Scr transcripts accumulate on the anterior ventral side of the embryo at stage 5 in a region that corresponds to the labial and prothoracic segments on the fate map. After germ band retraction, the strongest expression is observed in the suboesophageal ganglion and the anterior part of the prothoracic ganglion. Weaker staining is observed over the entire nervous system and brain. Strong labelling is also seen in the region of the pharynx.
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
labial segment

Comment: reference states >6.2-7.2 hr AEL

Additional Descriptive Data
D. melanogaster shows noticeable sexual dimorphism in its Scr expression pattern The prothoracic Scr expression domain in males extends upto the distal border of the metatarsus, whereas in case of female foreleg pupal disc, the expression will not extend to the distal margin.
Scr protein is located in the cytoplasm prior to embryonic stage 9 and is then nuclear.
In late non-wandering third instar larvae, high levels of Scr protein are detectable in the distal tibia and first tarsal segment region of the leg disc. Low expression is present in the rest of the disc. At 24hr APF, when sex comb rotation is complete, dsx and Scr develop roughly complementary expression patterns in the male leg. dsx is highest in the sex comb teeth and surrounding epidermal cells, while Scr expression is low or absent in sex comb teeth but highest in adjacent epidermal cells. The pattern is maintained at later stages. In females, dsx expression becomes very low or undetectable, and Scr expression in the distal first tarsal segment is much lower than in males.
In addition to expression in the labial and prothoracic ectoderm, the PS2 and PS3 regions of the CNS, and the visceral mesoderm of the anterior and posterior midgut, expression is observed in three new locations. These are a 4-cell-wide stripe in the ectoderm at stage 5 that partially overlaps the posterior edge of the maxillary en stripe, the embryonic salivary gland, and the dorsal ridge.
As observed previously, Scr antibodies stain the labial and prothoracic ectoderm, the 2nd and 3rd parasegments of the CNS, and the visceral mesoderm of the anterior and posterior midguts. A new antibody allowed the detection of weaker sites of expression in the precursors of the larval salivary glands, the dorsal ridge, and a stripe of ectodermal cells in the parasegment 2 region of stage 5 embryos.
Scr protein is ectopically expressed in leg discs of Pc3/+ larvae and this ectopic expression is suppressed in Pc3/brm2 larvae.
dpp and Scr proteins are expressed in adjacent non-overlapping domains in the visceral mesoderm, the Scr domain being posterior to the dpp domain. In dpps21/s2 mutants, the Scr domain is expanded anteriorly to encompass the visceral mesoderm cells that give rise to the gastric caeca which normally express dpp.
Scr protein is expressed in the visceral mesoderm close to the anterior tip of the midgut. At stage 13, the domain of expression extends to about 4 nuclei along the AP axis and spans the width of the visceral mesoderm. By stage 14, the domain has elongated to 6 nuclei and has split into dorsal and ventral patches on each side of the body. By stage 17, the patches of Scr expressing nuclei have stretched posteriorly over the midgut to form 4 rows, each starting at the base of a gastric caecum. The number of cells expressing Scr and the level of expression are significantly reduced in an Antp- background.
During embryogenesis, Scr protein is detected in the epidermis, in the nervous system, and in the visceral mesoderm. Scr protein is first detected in 3 hour embryos, in a band posterior to the cephalic furrow (parasegment 2). During germ band extension, label moves posteriorly 6-8 cells. Scr protein becomes visible in parasegment 3, in the lateral portion of the ectoderm, and in the mesoderm. Later in the extended germ band stage, labeling spreads in what is now the prothoracic segment. During germ band retraction, Scr protein is visible in the central nervous system and the visceral mesoderm, as well as in the labial and prothoracic segments. In stage 16 embryos, Scr protein is detected in a single segment-width of cells in the CNS.
Scr protein is first detected at early germ band retraction stage in a 4-5 cell width stripe in the midgut visceral mesoderm of parasegment 4. At later stages, this stripe expands to 6-7 cell widths, extending just anterior and just posterior to parasegment 4.
Scr protein is expressed in a slightly extended domain in homozygous ftz mutant embryos. Embryos homozygous for eve3 showed no Scr protein staining but there is some staining in embryos homozygous for eve4. Normal homeotic gene function is seen in embryos homozygous for en59, en54, en55, wgl-17, h41, odd5, prd4 and runB102. For an unknown reason, embryos homozygous for opa1 have a lack of Scr protein activity. No Scr gene expression is seen in ftz,prd or opa,prd double mutant embryos and there is normal staining in odd,eve double mutant embryos. The Scr protein domain is slightly extended in kni mutants and KrB206 mutants but missing in hb mutants.
During embryogenesis, Scr protein is first detected at the extended germ band stage in nuclei within the labial segment, and in the yolk mass. At the start of germ band contraction, it is detected within the first thoracic segment, in a band of nuclei along the anterior portion, and continues to be detected in labial nuclei. At the start of dorsal closure, Scr protein is detected in more nuclei in the anterior half of the first thoracic segment. When germ band contraction is complete, nuclei throughout the epidermis of the labial an first thoracic segments accumulate Scr protein; this staining continues past the completion of head involution. CNS expression of Scr protein is first detected at the start of head involution, in two regions of the ventral nerve cord: in a large group of nuclei within the posterior part of the subesophageal ganglia and 2-6 nuclei in the next more posterior segment. This staining continues past the completion of head involution. Scr protein is also detected in the midgut. In larvae and adults, Scr protein is found in the subesophageal ganglia. Larval staining is also detected in lab al and first thoracic imaginal discs, with faint staining observed in second and third thoracic leg discs.
Scr protein is detected in stages 11 and 12 in ectodermal cells of the parasegment 2 and 3 primordia. During stage 12 strong expression is observed in the labial lobes. After head involution initiates, Scr protein becomes visible in the posterior portion of the suboesophageal ganglion and in two small, paired clusters of cells in the first thoracic ganglion.
Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
Reporter: P{HZR+0.8X/H}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Scr-GAL4.1}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Scr-GAL4.2}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Scr-GAL4.3}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Scr-GAL4.4}
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\Scr in GBrowse 2
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
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
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 70 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 80 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Scr
Transgenic constructs containing regulatory region of Scr
Deletions and Duplications ( 53 )
Disrupted in
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
embryonic gastric caecum & parasegment 3, with Scer\GAL4how-24B
embryonic gastric caecum & parasegment 7, with Scer\GAL4how-24B
mesothoracic leg & sex comb | ectopic
mesothoracic leg & sex comb | ectopic (with Dp(3;Y)77ab), with Df(3R)Scr
mesothoracic leg & sex comb | ectopic (with Scr2)
mesothoracic leg & sex comb | ectopic (with Scr4)
mesothoracic leg & sex comb | ectopic (with Scr4), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrE2), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrMsc), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrP), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrRpl), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrScx)
mesothoracic leg & sex comb | ectopic (with ScrScx), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrT3), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic (with ScrTpl9)
mesothoracic leg & sex comb | ectopic (with ScrW)
mesothoracic leg & sex comb | ectopic (with ScrW), with Dp(3;Y)77ab
mesothoracic leg & sex comb | ectopic | conditional ts
mesothoracic leg & sex comb tooth | ectopic
metathoracic leg & sex comb | ectopic
metathoracic leg & sex comb | ectopic (with Dp(3;Y)77ab), with Df(3R)Scr
metathoracic leg & sex comb | ectopic (with Scr4)
metathoracic leg & sex comb | ectopic (with Scr4), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrMsc), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrP), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrRpl), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrScx)
metathoracic leg & sex comb | ectopic (with ScrScx), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrT2), with Dp(3;Y)77ab
metathoracic leg & sex comb | ectopic (with ScrTpl9)
metathoracic leg & sex comb | ectopic (with ScrW)
metathoracic leg & sex comb tooth | ectopic
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (31)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
 
7 of 15
No
Yes
 
6 of 15
No
Yes
4 of 15
No
No
4 of 15
No
No
4 of 15
No
No
4 of 15
No
No
 
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
 
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (31)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
 
8 of 15
Yes
Yes
6 of 15
No
Yes
3 of 15
No
No
3 of 15
No
No
 
3 of 15
No
No
3 of 15
No
No
2 of 15
No
No
2 of 15
No
No
 
2 of 15
No
No
 
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
 
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Rattus norvegicus (Norway rat) (35)
7 of 13
Yes
Yes
7 of 13
Yes
Yes
3 of 13
No
No
3 of 13
No
No
3 of 13
No
No
2 of 13
No
No
2 of 13
No
Yes
2 of 13
No
No
2 of 13
No
No
2 of 13
No
No
2 of 13
No
No
2 of 13
No
No
2 of 13
No
No
2 of 13
No
No
2 of 13
No
Yes
2 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Xenopus tropicalis (Western clawed frog) (29)
7 of 12
Yes
Yes
7 of 12
Yes
Yes
4 of 12
No
Yes
2 of 12
No
No
2 of 12
No
No
2 of 12
No
No
2 of 12
No
No
2 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
Danio rerio (Zebrafish) (37)
9 of 15
Yes
Yes
8 of 15
No
Yes
7 of 15
No
Yes
5 of 15
No
Yes
3 of 15
No
No
3 of 15
No
No
3 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Caenorhabditis elegans (Nematode, roundworm) (9)
6 of 15
Yes
Yes
5 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (2)
1 of 15
Yes
Yes
1 of 15
Yes
No
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG09190FFA )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila melanogaster
fruit fly
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG09150G7H )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W0KHE )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch butterfly
Danaus plexippus
Monarch butterfly
Heliconius melpomene
Postman butterfly
Apis florea
Little honeybee
Apis mellifera
Western honey bee
Bombus impatiens
Common eastern bumble bee
Bombus terrestris
Buff-tailed bumblebee
Linepithema humile
Argentine ant
Nasonia vitripennis
Parasitic wasp
Tribolium castaneum
Red flour beetle
Pediculus humanus
Human body louse
Rhodnius prolixus
Kissing bug
Cimex lectularius
Bed bug
Acyrthosiphon pisum
Pea aphid
Zootermopsis nevadensis
Nevada dampwood termite
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X0M88 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Ixodes scapularis
Black-legged tick
Stegodyphus mimosarum
African social velvet spider
Tetranychus urticae
Two-spotted spider mite
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G09XD )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (15)
4 of 10
4 of 10
3 of 10
2 of 10
2 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Model Summary Ribbon
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
     
    Disease Associations of Human Orthologs (via DIOPT v7.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    Functional Complementation Data
    Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
    Dmel gene
    Ortholog showing functional complementation
    Supporting References
    Interactions
    Summary of Physical Interactions
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    esyN Network Key:
    Suppression
    Enhancement

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    enhanceable
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Gene Group - Pathway Membership (FlyBase)
    External Data
    Linkouts
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map
    3-48
    Cytogenetic map
    Sequence location
    3R:6,823,120..6,849,981 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    84A5-84A5
    Limits computationally determined from genome sequence between P{PZ}pb04498 and P{lacW}l(3)L2100L2100
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    84B1-84B2
    (determined by in situ hybridisation)
    Based on complementation mapping, aberrations not specified.
    Experimentally Determined Recombination Data
    Left of (cM)
    Right of (cM)
    Notes
    Mapping based on ScrMsc.
    Stocks and Reagents
    Stocks (31)
    Genomic Clones (55)
    cDNA Clones (14)
     

    Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequences
    BDGP DGC clones
      Other clones
      Drosophila Genomics Resource Center cDNA clones

      For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

      cDNA Clones, End Sequenced (ESTs)
      Other clones
      RNAi and Array Information
      Linkouts
      DRSC - Results frm RNAi screens
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      Antibody Information
      Laboratory Generated Antibodies
      Commercially Available Antibodies
       
      Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
      Other Information
      Relationship to Other Genes
      Source for database identify of
      Source for identity of: Scr CG1030
      Source for database merge of
      Additional comments
      Other Comments
      Haploinsufficient locus (not associated with strong haplolethality or haplosterility).
      RNAi generated by PCR using primers directed to this gene causes a cell growth and viability phenotype when assayed in Kc167 and S2R+ cells.
      Transvection at the Scr gene is blocked by rearrangements that disrupt pairing, but is z independent. Silencing of the Scr gene in the second and third thoracic segments is disrupted by most chromosomal aberrations within the Scr gene.
      PP2A-B' has an essential role in positively modulating scr function.
      Scr regulates the nuclear localisation of exd in the salivary gland primordia through repression of hth expression.
      Candidate gene for quantitative trait (QTL) locus determining bristle number.
      The amino terminal of the Scr homeodomain is necessary for the specific activation of the fkh 37bp fkh250 element in vivo. Scr negatively regulates hth, which is required for the nuclear localization of the exd gene product.
      In the antennal disc, Scr exerts its effects by suppressing the transcription of hth and thus preventing the nuclear localisation of exd.
      Loss of exd activity is epistatic to loss of pb activity or loss of pb and Scr activity.
      exd protein localised to the nucleus is proposed to suppress tarsus development and activate arista development. In the mesodermal adepithelial cells of the leg imaginal discs, Scr protein is proposed to be required for the synthesis of a tarsus-inducer that when secreted acts on the ectoderm cells inhibiting nuclear accumulation of exd protein, such that tarsus determination is no longer suppressed and arista determination is no longer activated.
      Ras85D+ activity Scr function.
      Scr activity is required cell nonautonomously for tarsus determination. Specifically, Scr activity is required in the mesodermal adepithelial cells of all leg imaginal discs at late second/early third larval stage for the synthesis of a mesoderm-specific, tarsus inducing, signaling factor, which after secretion from the adepithelial cells acts on the overlaying ectodermal cells determining tarsus identity.
      Simultaneous removal of pb and Scr activity results in a proboscis-to-antenna transformation. Dominant negative pb molecules inhibit the activity of Scr indicating that pb and Scr interact in a multimeric protein complex in determination of proboscis identity. The absence of pb and Scr expression leads to antennal identity, expression of pb only leads to maxillary palp identity, expression of Scr only leads to tarsus identity and the expression of both pb and Scr leads to proboscis identity.
      The pattern of Scr expression during the embryonic development of D.melanogaster (Diptera), T.domestica (Thysanura, firebrats), O.fasciatus (Hemiptera, milkweed bug) and A.domestica (Orthoptera, cricket) is compared. Mapping both gene expression patterns and morphological characters onto the insect phylogenetic tree demonstrates that in the cases of wing suppression and comb formation the appearance of expression of Scr in the prothorax apparently precedes these specific functions.
      A biological role of tsh is to repress mod expression in the ectoderm and this negative control is performed independently of Scr.
      Mutations show weak interactions with high and low selection lines, abdominal and sternopleural bristle numbers are affected. Results suggest Scr is in the same genetic pathway as bristle number quantitative trait loci (QTL).
      Analysis of the distribution of certain gene products in embryos lacking Scr and cuticular phenotypes of embryos with mutations that blocked head involution suggests that Scr mutant embryos do not exhibit a labial to maxillary transformation, but instead lack of Scr function causes a loss of labial identity.
      A phylogenetic analysis of the Antp-class of homeodomains in nematode, Drosophila, amphioxus, mouse and human indicates that the 13 cognate group genes of this family can be divided into two major groups. Genes that are phylogenetically close are also closely located on the chromosome, suggesting that the colinearity between gene expression and gene arrangement was generated by successive tandem gene duplications and that the gene arrangement has been maintained by some sort of selection.
      Scr encodes a 417 amino acid protein with structural features common to many homeotic genes found within complexes. Structural analysis reveals at least four Scr transcripts exist.
      Ecol\lacZ reporter gene constructs have demonstrated that many of the Scr enhancers are located closer to the ftz promoter than to the Scr promoter, yet the expression patterns of the two genes do not overlap. The region carries ftz enhancers and repressor binding sites and Scr anterior\posterior midgut enhancer. The sequences in this region may be involved in preventing Scr enhancers from activating the ftz promoter.
      It has been previously reported that Scr embryos display partial transformation of the labial segment to a more anterior maxillary identity. This transformation seems unusual because the Dfd protein does not accumulate in the labial cells of an Scr mutant. It is proposed that the putative ectopic maxillary sense organ in Scr mutants may instead be the labial sensory organ which is now visible because of incomplete head involution.
      Sections of the Scr regulatory region may be important for regulation of Scr by Polycomb- and trithorax-group genes.
      The 75kb regulatory region of Scr has been dissected and tested in Ecol\lacZ reporter constructs for expression patterns. Scr expression in some tissues appears to be controlled by multiple regulatory elements that are separated, in some cases, by more than 20kb of intervening DNA. Regulatory sequences that direct reporter gene expression in an Scr-like pattern in the anterior and posterior midgut are embedded in the regulatory region of the ftz gene.
      Regulation of Scr in the labial segment and in the CNS requires the apparently synergistic action of multiple, widely spaced enhancer elements. Regulation in the prothorax also appears to be controlled by multiple enhancers, one complete pattern element and one subpattern element. Scr regulation in the visceral mesoderm is controlled by an enhancer(s) located in only one DNA fragment.
      Expression of Scr in C.elegans demonstrates the specificity of function of the Drosophila and C.elegans Hox proteins is conserved in an assay to control the anterior versus posterior migration of Q-cell decendents. The Drosophila protein can substitute the normal function of the C.elegans protein in three different cell-fate decisions.
      The authors name enhancer trap inserts, as e.g. l(3)N33, for which the lethality does not map to the P insert, but have not come up with a _gene_ name. 'Excision' derivatives generate lethals in two additional complementation groups, though in 4/5 derivatives the P elements have locally hopped rather than simply excised. In view of this it is premature to be naming genes, though mulspcons can be named.
      An Scr-regulated salivary gland gene has been identified by enhancer trapping in cytological region 85D.
      Experiments with heat shock constructs show that the pb product interacts with the Scr product.
      Scr is required to activate fkh expression.
      Restrictions on Scr protein activity are imposed by different genes in different tissues. Bithorax complex homeotic genes (excluding Ubx and abd-A) limit Scr transcription and function in the cuticle. Salivary gland induction by Scr in the trunk is limited by tsh and by Abd-B in the last abdominal segment.
      Heat shock induced expression of mouse Hox genes in Drosophila embryos deficient for homeotic genes demonstrates that functional hierarchy is a universal property of the homeobox genes. Correlations exist between the expression patterns of the mouse Hox genes along the antero-posterior body axis of mice and the extent of their effect along the antero-posterior body axis of flies.
      Ectopic expression of dpp eliminates Scr and Antp expression, attenuating abd-A expression, inducing Ubx, dpp, wg and tsh expression in the visceral mesoderm and inducing lab expression in the apposing endoderm. The result is failure of all of the morphogenetic events except formation of midgut constriction 2.
      trx exerts its effects by positively regulating homeotic gene expression, but Ubx, Antp, abd-A, Abd-B, Scr and Dfd all have different tissue-specific, parasegment-specific and promoter-specific reductions in expression in a trx mutant background.
      Antp homeodomain differs at only 5 amino acid positions from that of Scr : using ectopically expressed Antp::Scr fusion proteins, the specificity of Antp protein was shown to be determined by four specific amino acids in the flexible N-terminal arm of the homeodomain.
      Scr is expressed ectopically in embryos lacking bithorax complex genes. A secondary wave of Scr activation, requiring Antp, is triggered during germ band retraction by en. This is repressed by the bithorax complex genes in the meso- and metathoracic and the abdominal segments.
      The homologs of Antp, ftz, Scr, Dfd, Ama, bcd, zen, pb and lab, but not zen2 are all present in D.pseudoobscura.pseudoobscura, in the same linear order and similarly spaced along the chromosome as in D.melanogaster.
      Comparative analysis of the homeobox sequences reveals the subdivision of the Antp-type homeobox genes into three classes early in metazoan evolution, one includes Abd-B, the second includes abd-A, Ubx, Antp, Scr, Dfd and ftz, and the third includes zen, zen2, pb and lab.
      The N terminus of the homeodomain is critical for determining the specific effects of the Antp and Scr homeotic proteins in vivo, though other parts of the protein do have a role. The N terminal part of the homeodomain has been observed, in crystal structures and in NMR studies in solution, to contact the minor groove of the DNA.
      P-element mediated introduction of mouse Hox-1.3 under the influence of a heat inducible promoter causes Scr-like abnormalities in both embryonic and larval development.
      Different homeotic genes have specific local effects on Dfd expression.
      The PNS has been studied in embryos homozygous for Scr with antibodies that label specific sensory organs. The effect of ectopic expression of Scr was investigated on the normal development of sensory organs in the embryonic PNS.
      The Scr gene product is the primary determinant of salivary gland placode position along the anterior-posterior axis prior to stage 11 when Scr expression is confined to parasegment 2.
      ae expression is not modulated by Scr. Scr gene activity suppresses dorsala trunk development in the prothorax in the absence of ae gene activity. Scr is expressed ectopically in embryos deficient for tsh and Antp.
      Scr derepression by Pc mutants causes second and third leg to first leg transformations. brm functions as an upstream activator of Scr expression.
      Scr transcript pattern is altered in ae mutant embryos.
      Scr gene expression is differentially regulated both temporally and spatially in a manner that is sensitive to the structure of the locus. Inclusion of Pc3 allele causes complete misregulation of the Scr locus in the leg and wing imaginal discs.
      Scr is a complex locus with an extensive regulatory region that directs functions required for normal head and thoracic development in the embryo and adult.
      The functional organization of Scr is determined by a series of in phase deletions and is compared to that of Antp. Ectopic expression of Scr is incapable of producing an antennae to leg transformation and induces abnormalities in the head, no ectopic belts of denticles and mouthparts tend to gather at the anterior rather than fail to involute.
      E(z)+ activity is not required to initiate the expression patterns of Scr and Ubx but to maintain their repressed state.
      Scr lesions can be defined into three categories. The first inactivate the entire locus, result in embryonic lethality and transformations of the first thoracic to second thoracic identity. The second are recessive semi-lethals that result in transformations of the first thoracic to second thoracic identity. The third are dominant gain-of-function lesions, when heterozygous exhibit an Scr phenotype.
      Mutants in the shv region of dpp alter spatially localized expression of Scr, domain is extended anteriorly. Scr expression in the gastric caeca is repressed by dpp expression, caeca development is arrested leaving them short and broad.
      Scr acts in its proper domain in an exd mutant and is little affected by exd.
      Proper expression of Scr in the visceral mesoderm is essential for the development of the gastric caeca and the formation of the small constrictions that separate the caeca primordia from the main part of the midgut. In the visceral mesoderm Antp acts as a positive regulator of Scr expression.
      Scr has been cloned and sequenced. It encodes a homeodomain-containing protein.
      Expression domains of Scr have been identified in the midgut visceral mesoderm and the domain position defined with respect to parasegment boundaries.
      Expression of the homeotic gene Scr in the visceral mesoderm is studied in pair-rule and gap gene mutant backgrounds.
      Cell clones deficient for Pc and the BXC genes have abnormal wings and legs, Scr and en are derepressed in the absence of Pc and BXC function. By using the Pc- mutation and various BXC mutant combinations imaginal cell clones possessing different combinations of active homeotic genes have been generated. In the absence of BXC genes Pc- clones develop prothoracic patterns: Scr activity overrules Antp. Adding contributions of Ubx, abd-A and Abd-B results in thoracic or abdominal patterns.
      Homeotic selector mutations exhibit normal Dfd expression patterns.
      Scr is not involved in the posterior salm phenotype.
      Scr is one of the 18 loci identified in a screen for dominant modifiers of Pc and/or Antp phenotypes. Alleles of Pc, Pcl, Scm, Dll, brm, kto, Scr and trx show clear dominant enhancement or suppression of AntpScx, whereas alleles of vtd, Vha55, Su(Pc)37D, urd, mor, skd and osa do not.
      The DNA sequences of the homeobox region of 11 Drosophila genes, including Scr, have been compared.
      Mutants of Scr exhibit a reduction in sex comb teeth on the first leg.
      Scr mutants display homeotic transformation of the labium to maxilla and prothorax to mesothorax.
      Clonal analysis demonstrates that Scr is required in at least the ventral prothorax for specifying pro- as opposed to mesothoracic development. Ubx, Antp and Scr act in combinatorial fashion to specify segmental determination and have regulatory roles in controlling the selective expression of other genes.
      Null mutations at the locus result in embryonic lethality. Animals die at the end of embryogenesis and show evidence of homeotic transformation in the cuticle derived from the labial and first thoracic segments. The first thorax is transformed to a second thoracic identity and the labial segment toward maxillary. This latter phenotype is seen as a duplication of the maxillary sense organs and the cirri. Deletions of the locus as well as null alleles also produce a dominant phenotype most clearly seen in males as a reduction in the number of sex-comb teeth. This reduction is indicative of a partial transformation of first leg to second, a conclusion borne out by the recovery of hypomorphic alleles of the locus which as hemizygotes allow survival to the adult stage and have no obvious effect in the embryo. These survivors show a complete transformation of ventral prothorax to mesothorax including the presence of sternopleural bristles on the propleurae; they also show an apparent transformation of the dorsal prothorax toward a mesothoracic identity. In addition to these thoracic transformations, the labial palps are transformed toward a maxillary palp morphology. All of these adult transformations can also been seen in X-ray-induced somatic clones of Scr- cells. Thus Scr activity is needed for proper segmental identity in both the embryo and adult in the anterior-most segment of the thorax and the posterior-most metamere of the head. In the absence of Scr product these two segments are transformed divergently to the identity of the next most posterior and anterior metamere respectively. The only other homeotic mutation to produce such a divergent homeosis is pb, which appears to act similarly in the adjacent maxillary and labial segments of the adult head. In addition to these loss-of-function mutations there are several gain-of-function dominant alleles. All result in a similar phenotype in adults, most clearly seen in males as the production of sex combs on the second and third thoracic legs. Additionally, strong alleles of this type (ScrW, ScrP, and ScrS) show the loss of sternopleural bristles indicative of a more complete transformation of mesothorax to prothorax. All of these dominants are associated with genomic rearrangements and with the exception of ScrS act as recessive lethals (ScrMsc, ScrT1, ScrT2, and ScrP) or semi-lethals (ScrW and ScrT3) at the locus. Examination of animals carrying these lesions at the end of embryogenesis as heterozygotes with a normal chromosome or hemizygotes reveals no evidence of the gain-of-function transformation of T2 and T3 transformed to T1, only the loss-of-function phenotypes described above. These phenotypic observations have been extended by showing that Scr protein is accumulated ectopically in the second and third leg imaginal discs in dominant gain-of-function genotypes but not in the second and third thoracic segments at any point in embryogenesis. Thus it appears that the spatial pattern of Scr expression is differentially regulated at these two times. Genetic analyses have shown that at least one difference lies in Scr imaginal expression being subject to a transvection-like effect. The gain-of-function lesions cause or allow the ectopic expression of the structural gene on the trans- rather than the cis-coupled transcription unit. This is most clearly seen in the case of ScrT1, which is broken within the transcribed portion of Scr and is therefore incapable of making a functional gene product. Scr mRNA is first detected in embryos in early gastrulae in a band of cells just posterior to the cephalic furrow. Protein is not detected at this time but later during germ-band elongation; it is found in the region of the labial lobe. Subsequently, during germ-band retraction, RNA and protein are detected in the first thoracic segment with the highest concentration at the anterior border of this segment. RNA and protein are also detected in the subesophageal region of the CNS in the labial ganglion and in mesodermal cells associated with the anterior midgut. As head involution proceeds, the Scr-expressing cells of the labial segment are carried inside where they are found associated with the pharynx and the mouthparts at the end of embryogenesis. In the third larval instar, protein is found in the prothoracic leg discs, the dorsal prothoracic discs, the labial discs and a small group of cells in the stalk of the antennal portion of the eye-antennal disc where it attaches to the mouthparts. In addition to this disc expression, Scr protein is accumulated in the subesophageal region of the CNS. This spatial pattern of expression in the epidermis is consistent with the spectrum of defects seen in Scr- animals and clones.
      Origin and Etymology
      Discoverer
      Etymology
      Identification
      External Crossreferences and Linkouts ( 56 )
      Sequence Crossreferences
      NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
      GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
      GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
      RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
      UniProt/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
      UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
      Other crossreferences
      BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
      Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
      Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
      Flygut - An atlas of the Drosophila adult midgut
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
      KEGG Genes - Molecular building blocks of life in the genomic space.
      modMine - A data warehouse for the modENCODE project
      Linkouts
      BioGRID - A database of protein and genetic interactions.
      DroID - A comprehensive database of gene and protein interactions.
      DRSC - Results frm RNAi screens
      Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
      FLIGHT - Cell culture data for RNAi and other high-throughput technologies
      FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
      FlyMine - An integrated database for Drosophila genomics
      Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
      InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
      MIST (genetic) - An integrated Molecular Interaction Database
      MIST (protein-protein) - An integrated Molecular Interaction Database
      Synonyms and Secondary IDs (14)
      Reported As
      Symbol Synonym
      BG:DS07876.2
      Scr
      (Papadopoulos et al., 2019, Sánchez-Higueras et al., 2019, Ho et al., 2018, Rastogi et al., 2018, Rosales-Vega et al., 2018, Zhu et al., 2018, Eagen et al., 2017, Erceg et al., 2017, Held et al., 2017, Kline et al., 2017, Lakhotia, 2017, Liu et al., 2017, Requena et al., 2017, Sharma et al., 2017, Tomoyasu, 2017, Becker et al., 2016, Beh et al., 2016, Beira and Paro, 2016, Bürglin and Affolter, 2016, Carrasco-Rando et al., 2016, Jungreis et al., 2016, Ma et al., 2016, Niwa and Niwa, 2016, Pinto-Teixeira et al., 2016, Sarov et al., 2016, Shlyueva et al., 2016, Wani et al., 2016, Zandvakili and Gebelein, 2016, Baëza et al., 2015, Bataillé et al., 2015, Crocker et al., 2015, Dietz et al., 2015, Dupont et al., 2015, Ghasemi et al., 2015, Javeed et al., 2015, Li et al., 2015, Mariappa et al., 2015, O'Connell et al., 2015, Saadaoui et al., 2015, Yung et al., 2015, Ashwal-Fluss et al., 2014, Banreti et al., 2014, Boube et al., 2014, Sánchez-Higueras et al., 2014, Alfieri et al., 2013, Baek et al., 2013, Copur and Müller, 2013, Devi and Shyamala, 2013, Devi et al., 2013, Heffer and Pick, 2013, Mallo and Alonso, 2013, Merabet and Hudry, 2013, Pengelly et al., 2013, Percival-Smith et al., 2013, Saunders et al., 2013, Vasanthi et al., 2013, Atallah et al., 2012, Cook et al., 2012, Hudry et al., 2012, Lemons et al., 2012, Papadopoulos et al., 2012, Weiss et al., 2012, Ahn et al., 2011, Anderson et al., 2011, Bantignies et al., 2011, Chopra et al., 2011, Gehring, 2011, Gehring, 2011, Lelli et al., 2011, Lelli et al., 2011, Maruyama et al., 2011, Noro et al., 2011, Papadopoulos et al., 2011, Roy et al., 2011, Saadaoui et al., 2011, Slattery et al., 2011, Slattery et al., 2011, Tanaka et al., 2011, Tolhuis et al., 2011, Arvey et al., 2010, Bhatia et al., 2010, Herz et al., 2010, Hueber et al., 2010, Joshi et al., 2010, Papadopoulos et al., 2010, Papadopoulos et al., 2010, Scheuermann et al., 2010, Uhl et al., 2010, Chopra et al., 2009, Chung et al., 2009, Gambetta et al., 2009, Gambetta et al., 2009, Moazzen et al., 2009, Paré et al., 2009, Sivanantharajah and Percival-Smith, 2009, Svendsen et al., 2009, Zhai et al., 2009, Chung et al., 2008, Coiffier et al., 2008, Diop et al., 2008, González et al., 2008, Juven-Gershon et al., 2008, Kwong et al., 2008, Lemons and McGinnis, 2008, Noyes et al., 2008, Paré et al., 2008, Prince et al., 2008, Randsholt and Santamaria, 2008, Sanders et al., 2008, Tsubota et al., 2008, Bannina and Kopp, 2007, Beisel et al., 2007, de Ayala Alonso et al., 2007, Duboule, 2007, Graze et al., 2007, Harris and Beckendorf, 2007, Hueber et al., 2007, Joshi et al., 2007, Joshi et al., 2007, Kolesnikov and Beckendorf, 2007, Kopp and Barmina, 2007, Kopp et al., 2007, Mito et al., 2007, Negre and Ruiz, 2007, Ogishima and Tanaka, 2007, Pare et al., 2007, Parrish et al., 2007, Roy et al., 2007, Sandmann et al., 2007, Shroff and Orenic, 2007, Shroff et al., 2007, Stark et al., 2007, Taghli-Lamallem et al., 2007, Chopra and Mishra, 2006, Crane-Robinson et al., 2006, Joulia et al., 2006, Klymenko et al., 2006, Macdonald and Long, 2006, Muller and Kassis, 2006, Qi et al., 2006, Salvaing et al., 2006, Barmina et al., 2005, Mace et al., 2005, Mace et al., 2005, Pearson et al., 2005, Percival-Smith et al., 2005, Siepel et al., 2005, Gutierrez et al., 2004, Riede, 2004, Tayyab et al., 2004, Enright et al., 2003, Kaufman et al., 2002, Wong and Merritt, 2002, Chauvet et al., 2000)
      l(3)84Af
      Name Synonyms
      Sex Combs Reduced
      sex-combs reduced
      Secondary FlyBase IDs
      • FBgn0002844
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      References (617)