Allele Dmel\spi^SC1

General Information
Symbol	Dmel\spi^SC1	Species	D. melanogaster
Name		FlyBase ID	FBal0056122
Feature type	allele	Associated gene	Dmel\spi

Allele class	amorphic allele - genetic evidence
Mutagen	ethyl methanesulfonate
Recent Updates
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FB2013_03
FB2013_02
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Nature of the Allele
Allele class	amorphic allele - genetic evidence (Tio et al., 1994)
Mutagen	ethyl methanesulfonate (Tio et al., 1994)
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
Cytology
Phenotypic Data
Phenotypic Class
	lethal \| recessive (Tio et al., 1994)
Phenotype Manifest In
	eye photoreceptor cell \| somatic clone (Miura et al., 2006) mitotic cell cycle & eye disc \| somatic clone (Baker and Yu, 2001) ommatidium (Tio and Moses, 1997) photoreceptor cell R2 (Tio and Moses, 1997, Tio et al., 1994) photoreceptor cell R3 (Tio et al., 1994) photoreceptor cell R4 (Tio et al., 1994) photoreceptor cell R5 (Tio and Moses, 1997, Tio et al., 1994) photoreceptor cell R8 (Tio et al., 1994)
Detailed Description
	Statement Reference Photoreceptor differentiation is defective in somatic clones of spi^SC1 homozygous cells in the eye disc. This phenotype is rescued if the clones are made in a spi^Scer\UAS.cSa; Scer\GAL4^αTub84B.PL; Scer\GAL80^αTub84B.PL background and lack Scer\GAL80^αTub84B.PL. However, this rescue is not seen if spi^{CS.m.Scer\UAS} is used in place of spi^Scer\UAS.cSa. (Miura et al., 2006) Homozygous clones in the eye disc undergo less than half as many mitoses as control clones. Dividing cells within the clone are usually next to the boundary with wild-type cells. BrdU incorporation is normal in mutant cells. (Baker and Yu, 2001) Heterozygotes have wild-type wings. (Nagaraj et al., 1999) Germline clones reveal no requirement for spi in patterning the egg, or in the viability or patterning of the embryo. (Wasserman and Freeman, 1998) In mutant eye clones the initial single neuron stage ommatidia appear normal, as do their spacing. However no further progression occurs, and the clusters appear to be arrested at the one neuron stage. The wave of DNA synthesis immediately following the furrow is unaffected in spi mutant clones. The early development of the preclusters is normal up until the 5-cell stage. Development proceeds normally anterior to and in the furrow (up to the specification and early differentiation of the founding R8 photoreceptor cells) but the specification of R2 and R5, and all subsequent steps, fail. Homozygous spi mutant clones are apparently equal in size to their homozygous wild-type twin-spots. (Tio and Moses, 1997) Retinal clones induced during first larval instar show defects in the formation of photoreceptor cells R8, R2, R5, R3 and R4. (Tio et al., 1994)
External Data
Linkouts
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Other
Statement Reference Df(2R)CX1, spi^SC1 has visible \| dominant phenotype (Nagaraj et al., 1999)
Phenotype Manifest In
Enhancer of
Statement Reference spi^SC1 is an enhancer of phenotype of Egfr^E1 (Tio et al., 1994)
Suppressor of
Statement Reference spi[+]/spi^SC1 is a suppressor of phenotype of Src42A^Su(phl)1-1 (Zhang et al., 1999)
Other
Statement Reference Df(2R)CX1, spi^SC1 has wing phenotype (Nagaraj et al., 1999) Df(3L)γ3, spi^SC1 has photoreceptor cell R2 \| somatic clone phenotype (Yang and Baker, 2003) Df(3L)γ3, spi^SC1 has photoreceptor cell R3 \| somatic clone phenotype (Yang and Baker, 2003) Df(3L)γ3, spi^SC1 has photoreceptor cell R4 \| somatic clone phenotype (Yang and Baker, 2003) Df(3L)γ3, spi^SC1 has photoreceptor cell R5 \| somatic clone phenotype (Yang and Baker, 2003) Df(3L)γ3, spi^SC1 has photoreceptor cell R8 \| somatic clone phenotype (Yang and Baker, 2001)
Additional Comments
Genetic Interactions
Statement Reference In spi^SC1; Df(3L)γ3 double mutant somatic clones in the 3rd instar eye disc, photoreceptors R2-R5 undergo G1 arrest, but do not differentiate. (Yang and Baker, 2003) spi^SC1 ; Df(3L)γ3; double mutant clones in the eye disc develop similarly to spi^SC1 single mutant cells, but occasionally R8 spacing is affected so that twinned R8 cells are seen. (Yang and Baker, 2001) S^104E Df(2R)CX1 double heterozygotes show notching of the wing margin. (Nagaraj et al., 1999) Dominantly suppresses the ability of Src42A^Su(phl)1-1 to suppress the lethality of phl¹/Y flies. (Zhang et al., 1999)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Fails to complement	spi^133a (Faucheux et al., 2001)
Rescued by	spi¹/spi^SC1 is rescued by Scer\GAL4^da.G32/spi^Scer\UAS.cSa (Miura et al., 2006)
Not rescued by	spi¹/spi^SC1 is not rescued by spi^{CS.m.Scer\UAS}/Scer\GAL4^da.G32 (Miura et al., 2006)
Comments	Unlike spi^Scer\UAS.cSa; Scer\GAL4^da.G32, spi^{CS.m.Scer\UAS}; Scer\GAL4^da.G32 completely fails to rescue lethality due to spi¹/spi^SC1. (Miura et al., 2006)
Stocks ( 0 )

Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 3 )
Reported As
Symbol Synonym	spi^SC1 spi^SC (Faucheux et al., 2001) spi^SE1 (Szuts et al., 1998)
Name Synonym
Secondary FlyBase IDs

References ( 13 )
Research paper	Miura et al., 2006, Dev. Cell 10(2): 167--176 Palmitoylation of the EGFR ligand Spitz by Rasp increases Spitz activity by restricting its diffusion. [FBrf0190214] Frankfort and Mardon, 2004, Development 131(3): 563--570 Senseless represses nuclear transduction of Egfr pathway activation. [FBrf0167533] Yang and Baker, 2003, Dev. Cell 4(3): 359--369 Cell cycle withdrawal, progression, and cell survival regulation by EGFR and its effectors in the differentiating Drosophila eye. [FBrf0158858] Tsuda et al., 2002, Cell 110(5): 625--637 An EGFR/Ebi/Sno pathway promotes delta expression by inactivating Su(H)/SMRTER repression during inductive Notch signaling. [FBrf0151813] Baker and Yu, 2001, Cell 104(5): 699--708 The Egf receptor defines domains of cell cycle progression and survival to regulate cell number in the developing Drosophila eye. [FBrf0134491] Faucheux et al., 2001, Mol. Genet. Genomics 265(1): 14--22 Advantages of a P-element construct containing MtnA sequences for the identification of patterning and cell determination genes in Drosophila melanogaster. [FBrf0137022] Yang and Baker, 2001, Development 128(7): 1183--1191 Role of the EGFR/Ras/Raf pathway in specification of photoreceptor cells in the Drosophila retina. [FBrf0134563] Nagaraj et al., 1999, Development 126(5): 975--985 Role of the EGF receptor pathway in growth and patterning of the Drosophila wing through the regulation of vestigial. [FBrf0107900] Zhang et al., 1999, Genetics 151(2): 697--711 A genetic screen for modifiers of Drosophila Src42A identifies mutations in egfr, rolled and a novel signaling gene. [FBrf0107534] Szuts et al., 1998, Genes Dev. 12(13): 2022--2035 Functional intertwining of dpp and EGFR signaling during Drosophila endoderm induction. [FBrf0103047] Wasserman and Freeman, 1998, Cell 95(3): 355--364 An autoregulatory cascade of EGF receptor signaling patterns the Drosophila egg. [FBrf0105339] Tio and Moses, 1997, Development 124(2): 343--351 The Drosophila TGF homolog Spitz acts in photoreceptor recruitment in the developing retina. [FBrf0092704] Tio et al., 1994, Mech. Dev. 48(1): 13--23 spitz, a Drosophila homolog of transforming growth factor-, is required in the founding photoreceptor cells of the compound eye facets. [FBrf0079521]

Allele Dmel\spiSC1

Allele Dmel\spi^SC1