Allele Dmel\sca^BP2

General Information
Symbol	Dmel\sca^BP2	Species	D. melanogaster
Name		FlyBase ID	FBal0032653
Feature type	allele	Associated gene	Dmel\sca

Allele class	amorphic allele - genetic evidence, loss of function allele
Mutagen	PM hybrid dysgenesis, P-element activity
Recent Updates
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FB2013_03
FB2013_02
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Nature of the Allele
Allele class	amorphic allele - genetic evidence (Mlodzik et al., 1990, Hu et al., 1995) loss of function allele (Lee et al., 1996, Reddy et al., 1997)
Mutagen	P-element activity (Hu et al., 1995) PM hybrid dysgenesis (Mlodzik et al., 1990)
Mutations Mapped to the Genome

Type Location Additional Notes References
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype
Nature of the lesion	Statement Reference 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)
Cytology
Phenotypic Data
Phenotypic Class
	planar polarity defective (with sca^BP1) (Chou and Chien, 2002) planar polarity defective \| 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 (Ellis et al., 1994, Baker and Zitron, 1995) 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, Ellis et al., 1994, Baker and Zitron, 1995) 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 \| supernumerary (Rawlins et al., 2003, Powell et al., 2001) 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 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 the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement Reference sca^BP1/sca^BP2 has planar polarity defective phenotype, enhanceable by hh[+]/hh^bar3 (Chou and Chien, 2002)
Suppressed by
Statement Reference sca^BP2 has visible \| recessive phenotype, suppressible \| partially by Scer\GAL4^sca-73-1/sca::Hsap\FGA^Scer\UAS.cLa (Lee et al., 1998) sca^BP2 has visible \| recessive phenotype, suppressible \| partially by Scer\GAL4^sca-73-1/sca::Hsap\FGB^{C286A.Scer\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/aos::shg^{i.Scer\UAS.T:Hsap\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 \| partially by Scer\GAL4^sca-73-1/sca::Hsap\FGA^Scer\UAS.cLa (Lee et al., 1998) sca^BP2 has adult thorax & macrochaeta phenotype, suppressible \| partially by Scer\GAL4^sca-73-1/sca::Hsap\FGB^{C286A.Scer\UAS} (Lee et al., 1998)
NOT suppressed by
Statement Reference sca^BP2 has eye phenotype, non-suppressible by Gp150⁴/Gp150³ (Li et al., 2003) sca^BP2 has ommatidium phenotype, non-suppressible by Gp150⁴/Gp150³ (Li et al., 2003) sca^BP2 has photoreceptor cell R8 \| supernumerary phenotype, non-suppressible \| somatic clone by Egfr^f2 (Rawlins et al., 2003)
NOT Enhancer of
Statement Reference sca^BP2 is a non-enhancer of wing margin phenotype of Gp150^Scer\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^Scer\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. (Lee et al., 1998)
Complementation & Rescue Data
Fails to complement	sca^5-120 (Kaun et al., 2011)
Partially rescued by	sca^73-1/sca^BP2 is partially rescued by Scer\GAL4^sca-73-1/sca^{D654N.Scer\UAS} (Lee et al., 1998) sca^73-1/sca^BP2 is partially rescued by Scer\GAL4^sca-73-1/sca^{MSKF.Scer\UAS} (Lee et al., 1998) sca^73-1/sca^BP2 is partially rescued by Scer\GAL4^sca-73-1/sca^Scer\UAS.cEa (Lee et al., 1998) sca^73-1/sca^BP2 is partially rescued by Scer\GAL4^sca-73-1/sca^{Δ513-774.Scer\UAS} (Lee et al., 1998)
Not rescued by	sca^73-1/sca^BP2 is not rescued by Scer\GAL4^sca-73-1/sca^{Δ41-463.Scer\UAS} (Lee et al., 1998) sca^73-1/sca^BP2 is not rescued by Scer\GAL4^sca-73-1/sca^{Δ41-514.Scer\UAS} (Lee et al., 1998) sca^BP2 is not rescued by Scer\GAL4^pnr-MD237/sca^Scer\UAS.cEa (Renaud and Simpson, 2001)
Comments
Stocks ( 1 )
Bloomington	7320 cn¹ sca^BP2 bw¹/CyO
Notes on Origin
Discoverer

Comments
	No interaction with P{sev-svp1} or P{sev-svp2} exists. (Begemann et al., 1995) Mosaic analysis shows that sca⁺ has a function in the R8 cell. (Baker et al., 1990)
External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 1 )
Reported As
Symbol Synonym	sca^BP2
Name Synonym
Secondary FlyBase IDs

References ( 22 )

Generate a list of	All references relating to this allele ( 22 )

List References by type	Research paper ( 22 )
Recent research papers ( 2 )
	Kaun et al., 2011, Nat. Neurosci. 14(5): 612--619 A Drosophila model for alcohol reward. [FBrf0213574] Lubensky et al., 2011, Proc. Natl. Acad. Sci. U.S.A. 108(27): 11145--11150 A dynamical model of ommatidial crystal formation. [FBrf0214256] Show all research papers ...

Allele Dmel\scaBP2

Allele Dmel\sca^BP2