Allele Dmel\mbc^D11.2

General Information
Symbol	Dmel\mbc^D11.2	Species	D. melanogaster
Name		FlyBase ID	FBal0063880
Feature type	allele	Associated gene	Dmel\mbc

Map ( GBrowse )
Allele class	loss of function allele
Mutagen	ethyl methanesulfonate
Recent Updates
Description	What does this section display? This section contains items that were added to this record for each release. It currently only tracks new links between this FlyBase report and other FlyBase data classes (e.g. genes, references, stocks) or controlled vocabulary terms (e.g. GO, anatomy terms). What does this section not display? This section does not currently display links that were removed or gene model changes.
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FB2013_03
FB2013_02
All updates	Click here to see a list of all updates to this record from FB2010_08 and on.
Nature of the Allele
Allele class	loss of function allele (Bour et al., 2000)
Mutagen	ethyl methanesulfonate (Erickson et al., 1997, Balagopalan et al., 2006)
Mutations Mapped to the Genome

Type Location Additional Notes References point mutation 3R:19,617,913..19,617,913 comment=nucleotide position inferred by curator based on amino acid change reported in Figure 2 of FBrf0094649; mutations characterized in FBrf0094649 are reported to be GC to AT transitions at single nucleotides evidence=experimental reported_pr_change=E97@\|FBrf0094649 na_change=G19617913T pr_change=E96@\|mbc-PA (Erickson et al., 1997)
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: W97@. (Balagopalan et al., 2006) Nucleotide substitution: G?A. (Balagopalan et al., 2006) TGG to TAG nucleotide change. (Balagopalan et al., 2006) Amino acid replacement: E97@. (Erickson et al., 1997)
Cytology
Phenotypic Data
Phenotypic Class
	neuroanatomy defective \| embryonic stage (Biersmith et al., 2011)
Phenotype Manifest In
	A1-7 dorsal acute muscle 1 \| embryonic stage 15 (Menon et al., 2005) border follicle cell \| somatic clone (Duchek et al., 2001) embryonic myoblast (Balagopalan et al., 2006, Biersmith et al., 2011, Haralalka et al., 2011) embryonic myoblast \| germline clone (Balagopalan et al., 2006) lateral longitudinal fascicle (Biersmith et al., 2011) muscle founder cell \| embryonic stage (Shelton et al., 2009) presumptive embryonic/larval muscle system (Menon et al., 2005, Balagopalan et al., 2006) presumptive embryonic/larval muscle system \| germline clone (Balagopalan et al., 2006)
Detailed Description
	Statement Reference In homozygous mutant embryos, myoblasts are competent to migrate to the founder cells, but fusion does not occur. Homozygous embryos exhibit breaks in the outer longitudinal fascicles and a collapse of axons onto the MP1 fascicle tracts. Thinning of the longitudinal axon tracts and abnormal spacing between segments is also observed. (Biersmith et al., 2011) Unfused myoblasts are apparent in stage 16 homozygous embryos. Although the majority of founder cells examined remain mononucleate, a limited amount of fusion does occur, as binucleate muscle precursors that have undergone a single fusion event between a founder cell and a fusion competent myoblast (FCM) are seen in the mutant embryos. The muscle founders analysed and the percentage of segments in which the founder cell remains mononucleate are as follows: DA1 (72.1%), DO1 (76.3%), LO1 (90.2%), LT2 (93.4%), LT4 (95.0%), VT1 (78.9%), VA2 (84.6%). The overall level of myoblast fusion in embryos lacking both maternal and zygotic function is roughly comparable to that seen in zygotic mutant embryos. The F-actin foci which are seen in wild-type FCMs at points of contact with developing myofibers are less dense and somewhat dispersed in homozygous FCMs. In addition, the actin cytoskeletal network of the mutant FCMs is different from wild type, with many of the mutant cells showing a complete collapse of the network. (Haralalka et al., 2011) The eve-expressing DA1 founder cell undergoes no fusion in mbc[D11.2] embryos. (Shelton et al., 2009) Myoblast fusion is absent in mbc[D11.2] zygotic mutant embryos and in embryos derived from mbc[D11.2] germline clones. (Balagopalan et al., 2006) The extent of myoblast fusion in mbc^D11.2 mutant embryos is significantly reduced compared to wild type. (Menon et al., 2005) Homozygous embryos do not show any apparent defects in macrophage migration. (Paladi and Tepass, 2004) When mutant somatic clones are made in border cells, a strong effect is seen on border cell migration. At stage 10 only about 10% of mutant border cell clusters reach the oocyte. (Duchek et al., 2001)
External Data
Linkouts
Interactions
	Show the genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement Reference mbc^D11.2 has neuroanatomy defective \| embryonic stage phenotype, enhanceable by spg² (Biersmith et al., 2011)
NOT Enhanced by
Statement Reference mbc^D11.2 has neuroanatomy defective \| embryonic stage phenotype, non-enhanceable by Df(2L)CadN^Δ14 (Biersmith et al., 2011)
Phenotype Manifest In
NOT Enhanced by
Statement Reference mbc^D11.2 has embryonic myoblast phenotype, non-enhanceable by spg² (Biersmith et al., 2011) mbc^D11.2 has lateral longitudinal fascicle phenotype, non-enhanceable by Df(2L)CadN^Δ14 (Biersmith et al., 2011) mbc^D11.2 has lateral longitudinal fascicle phenotype, non-enhanceable by spg² (Biersmith et al., 2011)
Suppressed by
Statement Reference mbc^D11.2 has embryonic myoblast phenotype, suppressible by Rac1^V12.Scer\UAS/Scer\GAL4^sns.PK (Haralalka et al., 2011)
NOT suppressed by
Statement Reference mbc^D11.2 has embryonic myoblast phenotype, non-suppressible by Scer\GAL4^kirre-rP298/Rac1^V12.Scer\UAS (Haralalka et al., 2011) mbc^D11.2 has embryonic myoblast phenotype, non-suppressible by Scer\GAL4^sns.PK/Rac1^Scer\UAS.cLa (Haralalka et al., 2011)
Enhancer of
Statement Reference mbc^D11.2 is an enhancer of mesothoracic tergum phenotype of Pvr^{dsRNA.Scer\UAS}, Scer\GAL4^pnr-MD237 (Ishimaru et al., 2004) mbc^D11.2 is an enhancer of thorax phenotype of Pvr^{dsRNA.Scer\UAS}, Scer\GAL4^pnr-MD237 (Ishimaru et al., 2004)
Suppressor of
Statement Reference mbc^D11.2/mbc[+] is a suppressor of eye phenotype of Ced-12^Scer\UAS.cGa, Scer\GAL4^Mef2.PR, mbc^Scer\UAS.cBa (Geisbrecht et al., 2008) mbc^D11.2 is a suppressor of centripetally migrating follicle cell & actin filament phenotype of Pvr^{λ.Scer\UAS.T:Hsap\MYC}, Scer\GAL4^slbo.2.6 (Duchek et al., 2001) mbc^D11.2 is a suppressor of centripetally migrating follicle cell phenotype of Pvr^{λ.Scer\UAS.T:Hsap\MYC}, Scer\GAL4^slbo.2.6 (Duchek et al., 2001)
Other
Statement Reference mbc^D11.2, spg² has ventral nerve cord \| embryonic stage phenotype (Biersmith et al., 2011)
Additional Comments
Genetic Interactions
Statement Reference 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. mbc[D11.2], Df(2L)CadN[Δ14] embryos do not show increased axonal outgrowth or guidance defects compared to mbc[D11.2] embryos. (Biersmith et al., 2011) Expression of Rac1[V12.Scer\UAS] under the control of Scer\GAL4[sns.PK] rescues myoblast fusion in homozygous mbc[D11.2] embryos such that the somatic muscle pattern is almost wild type. Expression of Rac1[V12.Scer\UAS] under the control of Scer\GAL4[kirre-rP298] does not rescue myoblast fusion in homozygous mbc[D11.2] embryos. Expression of Rac1[Scer\UAS.cLa] under the control of Scer\GAL4[sns.PK] does not rescue myoblast fusion in homozygous mbc[D11.2] embryos. 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) The rough eye phenotype resulting from Scer\GAL4[GMR.PU]-mediated expression of Ced-12[Scer\UAS.cGa] and mbc[Scer\UAS.cBa] is suppressed by heterozygosity for mbc[D11.2]. (Geisbrecht et al., 2008)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Rescued by	mbc^D11.2/Df(3R)mbc⁹ is rescued by mbc^{NPxxP.Scer\UAS.T:Ivir\HA1}/Scer\GAL4^how-24B/Scer\GAL4^how-24B (Balagopalan et al., 2006) mbc^D11.2/Df(3R)mbc⁹ is rescued by mbc^{Scer\UAS.T:Ivir\HA1}/Scer\GAL4^how-24B/Scer\GAL4^how-24B (Balagopalan et al., 2006) mbc^D11.2/Df(3R)mbc⁹ is rescued by Scer\GAL4^how-24B/mbc^CBS.Scer\UAS/Scer\GAL4^how-24B (Balagopalan et al., 2006) mbc^D11.2/Df(3R)mbc⁹ is rescued by Scer\GAL4^how-24B/mbc^{NPxxP.Δ1807.Scer\UAS.T:Ivir\HA1}/Scer\GAL4^how-24B (Balagopalan et al., 2006) mbc^D11.2/Df(3R)mbc⁹ is rescued by Scer\GAL4^how-24B/Scer\GAL4^how-24B/mbc^{Δ1807.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006) mbc^D11.2/Df(3R)mbc⁹ is rescued by Scer\GAL4^how-24B/Scer\GAL4^how-24B/mbc^{ΔPRM.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006) mbc^D11.2 is rescued by mbc^{NPxxP.Scer\UAS.T:Ivir\HA1}/Scer\GAL4^twi.PG (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is rescued by mbc^{NPxxP.Δ1807.Scer\UAS.T:Ivir\HA1}/Scer\GAL4^sns.PK (Haralalka et al., 2011) mbc^D11.2 is rescued by mbc^{Scer\UAS.T:Ivir\HA1}/Scer\GAL4^sns.PK (Haralalka et al., 2011) mbc^D11.2 is rescued by mbc^{Scer\UAS.T:Ivir\HA1}/Scer\GAL4^twi.PG (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is rescued by Scer\GAL4^twi.PG/mbc^CBS.Scer\UAS (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is rescued by Scer\GAL4^twi.PG/mbc^{NPxxP.Δ1807.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is rescued by Scer\GAL4^twi.PG/mbc^{Δ1807.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is rescued by Scer\GAL4^twi.PG/mbc^{ΔPRM.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006)
Not rescued by	mbc^D11.2/Df(3R)mbc⁹ is not rescued by Scer\GAL4^how-24B/mbc^{ΔDHR1.Scer\UAS.T:Ivir\HA1}/Scer\GAL4^how-24B (Balagopalan et al., 2006) mbc^D11.2 is not rescued by mbc^{Scer\UAS.T:Ivir\HA1}/Scer\GAL4^kirre-rP298 (Balagopalan et al., 2006, Balagopalan et al., 2006, Haralalka et al., 2011) mbc^D11.2 is not rescued by Scer\GAL4^twi.PG/mbc^{DockerF6.4.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is not rescued by Scer\GAL4^twi.PG/mbc^{SH3W47K.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006) mbc^D11.2 is not rescued by Scer\GAL4^twi.PG/mbc^{ΔDHR1.Scer\UAS.T:Ivir\HA1} (Balagopalan et al., 2006, Balagopalan et al., 2006)
Comments	Expression of either mbc[Scer\UAS.T:Ivir\HA1] or mbc[NPxxP.Δ1807.Scer\UAS.T:Ivir\HA1] under the control of Scer\GAL4[sns.PK] restores fusion in mbc[D11.2] embryos and a wild-type somatic muscle pattern is formed. Myoblast fusion remains severely impaired in mbc[D11.2] embryos expressing mbc[Scer\UAS.T:Ivir\HA1] under the control of Scer\GAL4[kirre-rP298]. These embryos show a roughly twofold increase in muscle precursor formation (where a single fusion event between a founder cell and a fusion competent myoblast has occurred) compared to mbc[D11.2] embryos. (Haralalka et al., 2011) Expression of mbc[Scer\UAS.T:Ivir\HA1] rescues the myoblast fusion defect in mbc[D11.2] embryos when expressed using Scer\GAL4[twi.PG] or Scer\GAL4[how-24B] but not Scer\GAL4[kirre-rP298]. Scer\GAL4[twi.PG]-mediated expression of mbc[SH3W47K.Scer\UAS.T:Ivir\HA1] fails to rescue the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]-mediated expression of mbc[DockerF6.4.Scer\UAS.T:Ivir\HA1] fails to rescue the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[CBS.Scer\UAS] rescues the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[Δ1807.Scer\UAS.T:Ivir\HA1] rescues the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[NPxxP.Scer\UAS.T:Ivir\HA1] rescues the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[NPxxP.Δ1807.Scer\UAS.T:Ivir\HA1] rescues the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[ΔPRM.Scer\UAS.T:Ivir\HA1] rescues the mbc[D11.2] myoblast fusion defect. Scer\GAL4[twi.PG]- or Scer\GAL4[how-24B]-mediated expression of mbc[ΔDHR1.Scer\UAS.T:Ivir\HA1] fails to rescue the mbc[D11.2] myoblast fusion defect. (Balagopalan et al., 2006)
Stocks ( 1 )
Bloomington	4952 st¹ e¹ mbc^D11.2/TM3, Ser¹
Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 5 )
Reported As
Symbol Synonym	D11.2 (Balagopalan et al., 2006) Mbc^D11.2 (Ishimaru et al., 2004) mbc^D11.2 (Menon et al., 2005, Haralalka et al., 2011, Paladi and Tepass, 2004, Massarwa et al., 2007, Biersmith et al., 2011, Balagopalan et al., 2006, Bulchand et al., 2010, Shelton et al., 2009) mbc^Dll.2 (Gallio et al., 2004) mbcD11.2 (Geisbrecht et al., 2008)
Name Synonym
Secondary FlyBase IDs

References ( 18 )
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] Bulchand et al., 2010, PLoS ONE 5(2): e9374 The intracellular domain of dumbfounded affects myoblast fusion efficiency and interacts with rolling pebbles and loner. [FBrf0210103] Shelton et al., 2009, Development 136(7): 1159--1168 The immunoglobulin superfamily member Hbs functions redundantly with Sns in interactions between founder and fusion-competent myoblasts. [FBrf0207479] Geisbrecht et al., 2008, Dev. Biol. 314(1): 137--149 Drosophila ELMO/CED-12 interacts with Myoblast city to direct myoblast fusion and ommatidial organization. [FBrf0202723] Massarwa et al., 2007, Dev. Cell 12(4): 557--569 WIP/WASp-based actin-polymerization machinery is essential for myoblast fusion in Drosophila. [FBrf0201865] Balagopalan et al., 2006, Mol. Cell. Biol. 26(24): 9442--9455 The CDM superfamily protein MBC directs myoblast fusion through a mechanism that requires phosphatidylinositol 3,4,5-triphosphate binding but is independent of direct interaction with DCrk. [FBrf0194774] Menon et al., 2005, J. Cell Biol. 169(6): 909--920 A positive feedback loop between dumbfounded and rolling pebbles leads to myotube enlargement in Drosophila. [FBrf0187819] Wilson et al., 2005, Development 132(3): 491--501 FGF signalling and the mechanism of mesoderm spreading in Drosophila embryos. [FBrf0183935] Galletta et al., 2004, Mech. Dev. 121(12): 1455--1468 SNS: adhesive properties, localization requirements and ectodomain dependence in S2 cells and embryonic myoblasts. [FBrf0180484] Gallio et al., 2004, Development 131(15): 3605--3614 Rhomboid 3 orchestrates Slit-independent repulsion of tracheal branches at the CNS midline. [FBrf0179216] Ishimaru et al., 2004, EMBO J. 23(20): 3984--3994 PVR plays a critical role via JNK activation in thorax closure during Drosophila metamorphosis. [FBrf0180198] Paladi and Tepass, 2004, J. Cell Sci. 117(26): 6313--6326 Function of Rho GTPases in embryonic blood cell migration in Drosophila. [FBrf0187835] Duchek et al., 2001, Cell 107(1): 17--26 Guidance of cell migration by the Drosophila PDGF/VEGF receptor. [FBrf0139607] Menon and Chia, 2001, Dev. Cell 1(5): 691--703 Drosophila rolling pebbles: a multidomain protein required for myoblast fusion that recruits D-Titin in response to the myoblast attractant Dumbfounded. [FBrf0141462] Bour et al., 2000, Genes Dev. 14(12): 1498--1511 Drosophila SNS, a member of the immunoglobulin superfamily that is essential for myoblast fusion. [FBrf0128410] Erickson et al., 1997, J. Cell Biol. 138(3): 589--603 Drosophila myoblast city encodes a conserved protein that is essential for myoblast fusion, dorsal closure, and cytoskeletal organization. [FBrf0094649]
Supplementary material	Ishimaru et al., 2004, EMBO J. 23(20): Supplementary data. [FBrf0182966]

Allele Dmel\mbcD11.2

Allele Dmel\mbc^D11.2