Allele Dmel\spg²

General Information
Symbol	Dmel\spg²	Species	D. melanogaster
Name		FlyBase ID	FBal0015995
Feature type	allele	Associated gene	Dmel\spg
Also Known As	spg²⁴²

Allele class
Mutagen	ethyl methanesulfonate
Recent Updates
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FB2013_03
FB2013_02
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Nature of the Allele
Allele class
Mutagen	ethyl methanesulfonate (Tearle and Nusslein-Volhard, 1987, Postner et al., 1992)
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 Amino acid replacement: W487@. (Biersmith et al., 2011)
Cytology
Phenotypic Data
Phenotypic Class
	lethal \| embryonic stage \| maternal effect (Biersmith et al., 2011) lethal \| embryonic stage \| maternal effect \| recessive (Postner et al., 1992) neuroanatomy defective \| embryonic stage (Biersmith et al., 2011) neuroanatomy defective \| embryonic stage (with Df(3R)3450) (Biersmith et al., 2011) neuroanatomy defective \| embryonic stage (with spg³) (Biersmith et al., 2011)
Phenotype Manifest In
	lateral longitudinal fascicle (Biersmith et al., 2011) lateral longitudinal fascicle (with Df(3R)3450) (Biersmith et al., 2011) lateral longitudinal fascicle (with spg³) (Biersmith et al., 2011)
Detailed Description
	Statement Reference Eggs produced from spg[2] homozygous mothers with a mutant paternal spg[2] allele die early in embryonic development. Homozygous spg[2] or spg[2]/Df(3R)3450 or spg[2]/spg[3] embryos exhibit minor defects in axonal patterns: infrequent breaks in the outer longitudinal tract and occasional thinning of these tracts. Homozygous spg[2] embryos do not exhibit myoblast fusion defects. (Biersmith et al., 2011) Embryos from homozygous mutant spg females lack actin caps over interphase nuclei at the syncytial blastoderm stage. Embryos from mothers carrying combinations of spg¹, spg² or spg³³⁵ die soon after gastrulation. (Postner et al., 1992)
External Data
Linkouts
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement Reference spg² has neuroanatomy defective \| embryonic stage phenotype, enhanceable by Ced-12^19F3 (Biersmith et al., 2011) spg² has neuroanatomy defective \| embryonic stage phenotype, enhanceable by Df(2L)CadN^Δ14/+ (Biersmith et al., 2011) spg² has neuroanatomy defective \| embryonic stage phenotype, enhanceable by Df(2L)CadN^Δ14/Df(2L)CadN^Δ14 (Biersmith et al., 2011)
Enhancer of
Statement Reference spg² is an enhancer of neuroanatomy defective \| embryonic stage phenotype of Ced-12^19F3 (Biersmith et al., 2011) spg² is an enhancer of neuroanatomy defective \| embryonic stage phenotype of mbc^D11.2 (Biersmith et al., 2011)
Phenotype Manifest In
Enhanced by
Statement Reference spg² has lateral longitudinal fascicle phenotype, enhanceable by Ced-12^19F3 (Biersmith et al., 2011)
NOT Enhancer of
Statement Reference spg² is a non-enhancer of embryonic myoblast phenotype of mbc^D11.2 (Biersmith et al., 2011) spg² is a non-enhancer of lateral longitudinal fascicle phenotype of mbc^D11.2 (Biersmith et al., 2011)
Other
Statement Reference mbc^D11.2, spg² has ventral nerve cord \| embryonic stage phenotype (Biersmith et al., 2011)
Additional Comments
Genetic Interactions
Statement Reference Compared to Ced-12[19F3]/Ced-12[19F3] or spg[2]/spg[2] single mutants, a consistent increase in longitudinal axon defects is observed in the double homozygous mutants. There is also an increase in axons that inappropriately cross the midline, and abnormalities in the spacing between adjacent segments is enhanced. The final muscle pattern in Ced-12[19F3]/Ced-12[19F3], spg[2]/spg[2] double mutant embryos appears wild type. In mbc[D11.2]/mbc[D11.2], spg[2]/spg[2] double mutants, myoblasts fail to fuse but still cluster around the founder cells (as in mbc[D11.2]/mbc[D11.2] mutants). There is no significant increase in broken fascicles or the collapse of the outer longitudinal tracts in mbc[D11.2], spg[2] double mutants over mbc[D11.2] mutants alone. However, there is an increase in midline fascicle crossing in the double mutants. Abnormal positioning of the ventral nerve cord is also observed in the double mutants. Df(2L)CadN[Δ14]/+ in a spg[2] homozygous background increases the occurrence of axon outgrowth defects over those seen in spg[2] alone. Df(2L)CadN[Δ14]/Df(2L)CadN[Δ14], spg[2] embryos show more severe defects, with greater than additive increase in ectopic midline crossing. (Biersmith et al., 2011) mbc[D11.2] spg[2] double mutant embryos have a roughly comparable overall level of myoblast fusion compared to mbc[D11.2] single mutant embryos. (Haralalka et al., 2011)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Rescued by	spg² is rescued by Scer\GAL4^nos.PG/spg^Scer\UAS.cBa (Biersmith et al., 2011)
Comments	The early lethality associated with embryos produced from spg[2] homozygous mothers with a mutant paternal spg[2] allele is rescued by expressing spg[Scer\UAS.cBa] with Scer\GAL4[nos.PG]. (Biersmith et al., 2011)
Stocks ( 0 )

Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 2 )
Reported As
Symbol Synonym	spg² spg²⁴² (Pichler et al., 2003, Postner et al., 1992, Tearle and Nusslein-Volhard, 1987, Haralalka et al., 2011, Biersmith et al., 2011)
Name Synonym
Secondary FlyBase IDs

References ( 5 )
Research paper	Biersmith et al., 2011, PLoS ONE 6(1): e16120 The DOCK Protein Sponge Binds to ELMO and Functions in Drosophila Embryonic CNS Development. [FBrf0212890] Haralalka et al., 2011, Development 138(8): 1551--1562 Asymmetric Mbc, active Rac1 and F-actin foci in the fusion-competent myoblasts during myoblast fusion in Drosophila. [FBrf0213340] Postner et al., 1992, J. Cell Biol. 119: 1205--1218 Maternal effect mutations of the sponge locus affect actin cytoskeletal rearrangements in Drosophila melanogaster embryos. [FBrf0056436]
Abstract	Pichler et al., 2003, A. Dros. Res. Conf. 44 Suppl.: 1023C Cytological analysis of nuclear density domains and cloning of a locus on the X-chromosome required for nuclear spacing in syncytial blastoderm embryos. [FBrf0157104]
Stock list	Tearle and Nusslein-Volhard, 1987, D. I. S. 66: 209--269 Tubingen mutants and stock list. [FBrf0045941]

Allele Dmel\spg2

Allele Dmel\spg²