FlyBase Allele Report: Dmel\sca[BP2]

General Information

Symbol

Dmel\sca^BP2

Species

D. melanogaster

Name

FlyBase ID

FBal0032653

Feature type

allele

Associated gene

Dmel\sca

Associated Insertion(s)

Carried in Construct

Key Links

Allele class

loss of function allele

amorphic allele - genetic evidence

Mutagen

Nature of the Allele

Allele class

amorphic allele - genetic evidence

(Hu et al., 1995, Mlodzik et al., 1990)

loss of function allele

(Reddy et al., 1997, Lee et al., 1996)

Mutagen

PM hybrid dysgenesis

(Mlodzik et al., 1990)

P-element activity

(Hu et al., 1995)

Progenitor genotype

Cytology

Description

Deletion of the transcription start site.

(Hu et al., 1995)

2kb deletion at the 5' end of the gene, removing the first exon, including the transcription start site and the beginning of the open reading frame.

(Baker et al., 1990)

2kb deletion spanning coordinate 0 on the sca map, transcription start site.

(Mlodzik et al., 1990)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

Variant Molecular Consequences

Associated Sequence Data

DDBJ / EMBL / GenBank

DNA sequence

Protein sequence

UniProtKB/Swiss-Prot

UniProtKB/TrEMBL

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

abnormal planar polarity (with sca^BP1)

(Chou and Chien, 2002)

abnormal planar polarity | cell non-autonomous | somatic clone

(Chou and Chien, 2002)

visible

(Mlodzik et al., 1990)

visible | recessive

(Lee et al., 1998)

Phenotype Manifest In

acrostichal bristle

(Renaud and Simpson, 2001)

adherens junction

(Renaud and Simpson, 2001)

adult cuticle

(Renaud and Simpson, 2001)

adult thorax & macrochaeta

(Lee et al., 1998)

antennal sense organ

(Reddy et al., 1997)

chemosensory ventral triple row & microchaeta | ectopic

(Rawlins et al., 2003)

dorsal triple row & microchaeta | ectopic

(Rawlins et al., 2003)

dorsocentral bristle | ectopic

(Rawlins et al., 2003)

eo neuron

(Renaud and Simpson, 2001)

external sensory organ

(Renaud and Simpson, 2001)

external sensory organ precursor cell | ectopic

(Renaud and Simpson, 2001)

eye

(Li et al., 2003, Ellis et al., 1994)

eye photoreceptor cell

(Baker and Zitron, 1995, Ellis et al., 1994)

leg & macrochaeta

(Mlodzik et al., 1990)

microchaeta

(Renaud and Simpson, 2001)

microchaeta & mesothoracic tergum (with sca¹)

(Renaud and Simpson, 2002)

microchaeta & mesothoracic tergum | supernumerary | somatic clone

(Renaud and Simpson, 2002)

microchaeta | ectopic

(Renaud and Simpson, 2001)

morphogenetic furrow & filopodium | somatic clone

(Chou and Chien, 2002)

ommatidium

(Li et al., 2003, Baker and Zitron, 1995, Ellis et al., 1994)

ommatidium (with sca^BP1)

(Chou and Chien, 2002)

ommatidium | cell non-autonomous | somatic clone

(Chou and Chien, 2002)

photoreceptor cell R8

(Baker and Zitron, 1995)

photoreceptor cell R8 | increased number

(Rawlins et al., 2003, Powell et al., 2001)

proneural cluster | pupal stage (with sca¹)

(Corson et al., 2017)

scutellar bristle | ectopic

(Rawlins et al., 2003)

scutum & macrochaeta

(Mlodzik et al., 1990)

sensory mother cell

(Renaud and Simpson, 2002)

sensory mother cell | somatic clone

(Renaud and Simpson, 2002)

septate junction

(Renaud and Simpson, 2001)

tormogen cell

(Renaud and Simpson, 2001)

tormogen cell | ectopic

(Renaud and Simpson, 2001)

trichogen cell

(Renaud and Simpson, 2001)

trichogen cell | ectopic

(Renaud and Simpson, 2001)

wing & macrochaeta

(Mlodzik et al., 1990)

Detailed Description

Statement

Reference

sca¹/sca^BP2 mutants, the pupal notum shows splitting of proneural stripes two and four, to form supernumerary rows.

(Corson et al., 2017)

Mutant animals have eyes with bigger and smaller ommatidia.

(Li et al., 2003)

Twinning of R8 photoreceptor cells is seen in mutant animals.

(Rawlins et al., 2003)

sca^BP2 homozygous flies have extra dorsocentral, scutellar and recurved wing margin bristles (chemosensory ventral triple row + dorsal triple row).

(Rawlins et al., 2003)

Cytoplasmic extensions, extending from the morphogenetic furrow into sca^BP2 mutant clones, follow convoluted paths rather than being straight and aligned with each other as in wild-type. Ommatidial clusters posterior to sca^BP2 mutant clones that overlap the MF, display a severe over-rotation phenotype, often reaching 110^o-120^o. sca^BP1/sca^BP2 eyes and eye discs exhibit significant over-rotation of ommatidia.

(Chou and Chien, 2002)

sca^BP2/sca¹ animals exhibit abnormal patterning of the notal microchaetae. Instead of being aligned in five straight rows, as seen in wild-type, they are arranged chaotically. During pupal development from 13 to 24 hours post fertilisation, the sensory organ precursors (SOPs) in sca^BP2 mutants are poorly aligned from early time points. They emerge in greater numbers and earlier than in wild-type. The order of appearance of the rows (1 and 5, then 3 then 2 and 4) is less strict than in the wild-type, although rows 1 and 5 do seem to appear first. The only row that displays, more or less, a correct initial alignment is row 1. The disorganised nature of the SOP pattern is never resolved during pupal development and becomes progressively more chaotic. SOPs move around even more than seen in wild-type but follow are complex roundabout path. The speed of movement, and orientation appear wild-type. Daughter cells are also frequently seen to move apart. When alignment is examined more closely, it is seen that mutant SOPs become less and less well aligned with time. sca^BP2 somatic clones in the notum exhibit more bristles and the bristle organs move significantly more than those seen in wild-type. A greater proportion of mutant bristles are found on the borders of clones, suggesting a movement towards surrounding wild-type tissue.

(Renaud and Simpson, 2002)

40% of mutant ommatidia contain two or three R8s derived from the R8 equivalence group. R8s can be adjacent or not, indicating that selection may be stochastic.

(Powell et al., 2001)

Heterozygous mutant animals display a bristle density that is slightly higher than the wild-type. Homozygous mutants show a marked increase in density, as well as bristles that are less evenly spaced than wild-type: The acrostichal microchaetes also fail to align into rows. Despite this disorganisation, bristle organs are never adjacent, each bristle is surrounded by epidermal cells. Occasionally in homozygous mutants, double-bristle shafts and/or sockets are observed. These structures are due to abnormal fate assignments of the five cells of a single bristle organ. The precise consistent spatial arrangement of these cells in wild-type is lost, also cells from a single lineage are occasionally situated some distance from each other. Homozygous mutant larvae show an excess of more closely spaced microchaetae precursors. All of the precursors including the supernumerary ones, form together in a short period of time and by 15 hrs post pupariation. When homozygous mutant somatic clones are made in the notum the spacing between bristles is approximately wild-type. The epithelium of homozygous mutant animals is disorganised. The epithelium appears uneven, holes are visible between cells. The cuticle is thinner, deposited in irregular layers, and separated from the epithelium. Mutant cells are also often of irregular shape. Adherens and septate junctions are present in the mutant but are reduced in number and appear to be modified. Adherens junctions are often located less apically and septate junctions appear larger than normal.

(Renaud and Simpson, 2001)

Homozygous, sca^OB7/sca^BP2, sca^UM2/sca^BP2 and sca^MSKF/sca^BP2 flies have extra thoracic bristles.

(Lee et al., 1998)

Several bifurcated sensilla are seen on the third antennal segment.

(Reddy et al., 1997)

No effect on the faf eye phenotype.

(Huang and Fischer-Vize, 1996)

Approximately 50% of ommatidia contain the normal number and arrangement of photoreceptor cells, although interommatidial spacing and orientation of individual ommatidia is variable. The remaining ommatidia contain more than one R8 cell and a variable number of other photoreceptor cells, in different arrangements. The number of R8 cells is increased in sca^BP2/sca^UM2 N^l1N-ts1 double mutants compared to N^l1N-ts1 single mutants, and no regular array of R8 cells can be seen.

(Baker and Zitron, 1995)

Eyes have oversized facets with too many photoreceptors, or two or more normal R-cell complements enclosed by only one set of pigment cells. Some ommatidia have too few photoreceptor cells or altered orientation with respect to each other. Eye discs of mutants reveal irregular ommatidial spacing in the morphogenetic furrow. More than one cell per cluster can become R8.

(Ellis et al., 1994)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Enhanced by

Statement

Reference

sca^BP1/sca^BP2 has abnormal planar polarity phenotype, enhanceable by hh[+]/hh^bar3

(Chou and Chien, 2002)

Suppressed by

Statement

Reference

sca^BP2 has visible | recessive phenotype, suppressible by Scer\GAL4^sca-73-1/sca::Hsap\FGA^UAS.cLa

(Lee et al., 1998)

sca^BP2 has visible | recessive phenotype, suppressible by Scer\GAL4^sca-73-1/sca::Hsap\FGB^C286A.UAS

(Lee et al., 1998)

Phenotype Manifest In

Enhanced by

Statement

Reference

sca^BP1/sca^BP2 has ommatidium phenotype, enhanceable by hh[+]/hh^bar3

(Chou and Chien, 2002)

sca^BP2 has microchaeta phenotype, enhanceable by Scer\GAL4^unspecified/shg^{i.UAS.Tag:SS(aos),Tag:MYC}

(Renaud and Simpson, 2001)

NOT Enhanced by

Statement

Reference

sca^BP2 has eye phenotype, non-enhanceable by Gp150⁴/Gp150³

(Li et al., 2003)

sca^BP2 has ommatidium phenotype, non-enhanceable by Gp150⁴/Gp150³

(Li et al., 2003)

Suppressed by

Statement

Reference

sca^BP2 has adult thorax & macrochaeta phenotype, suppressible by Scer\GAL4^sca-73-1/sca::Hsap\FGA^UAS.cLa

(Lee et al., 1998)

sca^BP2 has adult thorax & macrochaeta phenotype, suppressible by Scer\GAL4^sca-73-1/sca::Hsap\FGB^C286A.UAS

(Lee et al., 1998)

NOT suppressed by

Statement

Reference

sca^BP2 has ommatidium phenotype, non-suppressible by Gp150⁴/Gp150³

(Li et al., 2003)

sca^BP2 has eye phenotype, non-suppressible by Gp150⁴/Gp150³

(Li et al., 2003)

sca^BP2 has photoreceptor cell R8 | increased number phenotype, non-suppressible by Egfr^f2

(Rawlins et al., 2003)

NOT Enhancer of

Statement

Reference

sca^BP2 is a non-enhancer of wing margin phenotype of Gp150^UAS.cLa, Scer\GAL4^dpp.blk1

(Li et al., 2003)

NOT Suppressor of

Statement

Reference

sca^BP2 is a non-suppressor of wing margin phenotype of Gp150^UAS.cLa, Scer\GAL4^dpp.blk1

(Li et al., 2003)

Additional Comments

Genetic Interactions

Statement

Reference

The addition of Gp150³/Gp150⁴ has no effect on the sca^BP2 eye phenotype. When sca^BP2 is added to Gp150^Scer\UAS.cLa, Scer\GAL4^dpp.blk1 animals, no effect is seen on the Gp150^Scer\UAS.cLa wing margin phenotype.

(Li et al., 2003)

Twinned R8 cells can be observed in Egfr^f2 sca^BP2 double mutant clones in the eye disc.

(Rawlins et al., 2003)

The increased bristle number in ed^4.12; sca^BP2 double homozygotes is consistent with an additive rather than a synergistic effect of the two muations.

(Rawlins et al., 2003)

The ommatidial rotation phenotype seen in sca^BP1/sca^BP2 eyes is dominantly enhanced by hh^bar3.

(Chou and Chien, 2002)

Overexpression of argos::shg^{i.Scer\UAS.T:Hsap\MYC} in all cells of the medial half of the notum, results in a slight increase in bristle density in a sca^BP2 mutant background.

(Renaud and Simpson, 2001)

Xenogenetic Interactions

Statement

Reference

sca::Hsap\FGA^Scer\UAS.cLa or sca::Hsap\FGB^{C286A.Scer\UAS} expressed under the control of Scer\GAL4^sca-73-1 partially rescues the sca^BP2/sca^73-1 extra thoracic bristle phenotype. sca::Hsap\FGG^Scer\UAS.cLa expressed under the control of Scer\GAL4^sca-73-1 does not rescue the sca^BP2/sca^73-1 extra thoracic bristle phenotype and may increase the number of ectopic bristles compared to the number seen in sca^BP2/sca^73-1 flies.