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General Information
Symbol
Dmel\numb2
Species
D. melanogaster
Name
FlyBase ID
FBal0013187
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
nb2
Key Links
Mutagen
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference
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
Phenotype Manifest In

head bristle & socket | supernumerary | somatic clone

Detailed Description
Statement
Reference

numb2 clones generated in the larval eye disc do not result in ommatidial rotation phenotypes - planar cell polarity defects.

numb2 mutant neuroblast clones contain many supernumerary neuroblasts and show an aberrant accumulation of newly-born (ase[+] erm[-]) immature immature Intermediate Neural Progenitors (INPs) compared to controls.

Homozygous intestinal stem cell clones form large clones over time, as do wild-type controls.

numb2 mutant embryos show normal development of two svp-positive precursors per hemisegment, but these divide to give only two pericardial cells and no svp-positive cardioblasts develop.

In numb2 mutant embryos eve-positive pericardial cell numbers double, and eve-positive DA1 muscles are lost.

Both vMP2 and dMP2 siblings adopt the vMP2 fate and extend axons anteriorly in numb2 mutant embryos.

In numb2 mutants, the pIIb cell is transformed into an ectopic pIIa cell. The most common phenotype of numb2 mutants is three socket cells and one shaft cell.

Within numb2 pIIa-pIIb cells, an apical actin-rich structure (ARS) is formed normally.

Single cell mutant clones induced in a single neuroblast generate a clone containing multiple neuroblasts plus neuronal progeny, in contrast to single cell wild-type clones which give rise to a clone containing one neuroblast plus neuronal progeny.

100% of heterozygous flies show rhythmic locomotor activity, with a period of 24.2 +/- 0.1 hours. 94% of numb2/numbSW flies show rhythmic locomotor activity, with a period of 24.3 +/- 0.1 hours.

Large homozygous clones in the head result in a multiple socket phenotype in the sensory organs.

Glial development in the NGB 6-4T lineage is not affected in mutant embryos.

6.0 odd-expressing pericardial cells and 4.2 cardioblasts develop per abdominal hemisegment in mutant embryos (in contrast to the wild-type number of 4.2 odd-expressing pericardial cells and 6.0 cardioblasts per abdominal hemisegment). The precise alignment of the cardioblasts is disrupted leading to "broken rows" of cardioblasts in mutant embryos.

Both progeny from the GMC4-2a ganglion mother cell appear to adopt the RP2sib neuronal fate in about 1/4 cases. Embryos lacking both maternal and zygotic numb, produced by making numb4 germline clones, display near-complete expressivity of numb phenotypes. Both progeny from the GMC4-2a ganglion mother cell appear to adopt the RP2sib neuronal fate. Both progeny from the GMC1-1a ganglion mother cell appear to adopt the pCC neuronal fate. Both progeny from the ganglion mother cell that normally mothers the U/CQ and U/CQ sibling neurons appear to adopt the U/CQ neuron fate. EL neurons almost completely fail to appear. Maternal loss alone has almost no effect on RP2/RP2sib, U/Usib, EL, and pCC/aCC lineages. Zygotic loss of numb2 allows about half the wild-type number of RP2 neurons, about 7 times the wild-type number of U/CQ neurons, and about 6% of the normal number of EL neurons to develop. the pCC/aCC lineage appears to be unaffected.

numb2 embryos lack the DA1 muscles and have twice the normal number of eve-expressing pericardial cells (EPCs). numb2; zfh12 double mutant embryos have no EPCs and no DA1 muscles, except for rarely 1 or 2 EPCs are present.

Many muscles are absent in numb1/numb2 embryos, particularly in the dorsal region. Most myocardial cells are formed. The number of eve-expressing pericardial cells is double that of wild-type.

The RP2sib neuron, vMP2 neuron and U neuron are all duplicated at the expense of their siblings. The number of EL neurons is strongly reduced. pCC/aCC are unaffected. This phenotype is the reciprocal of that shown for spdo, Dl, N and mam embryos. The phenotype of numb; spdo double mutants is identical to embryos lacking spdo alone. The eve+ EL neurons are completely rescued.

Homozygous clones in the IIa cell due to Scer\FLP1Scer\UAS.cBa expression driven by Scer\GAL4sca-109-68 cause a double-socket phenotype. Clones generated from Scer\GAL4sca-537.4 cause sense organs with three sockets and one hair or four sockets.

Homozygous clones induced in the sensory organ precursor daughter IIa cells of the adult external sense organs, when Scer\FLP1Scer\UAS.cBa expression is driven by Scer\GAL4sca-109-68, produce a double socket phenotype.

apparently null since the neuronal phenotype of homozygotes is indistinguishable from that of hemizygotes.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
Statement
Reference

numb2 has visible phenotype, suppressible by Su(H)8

Suppressor of
Statement
Reference

numb[+]/numb2 is a suppressor | partially of abnormal planar polarity | male | adult stage phenotype of dsh1

Phenotype Manifest In
Enhanced by
Suppressed by
Enhancer of
Statement
Reference

numb[+]/numb2 is an enhancer of eo neuron phenotype of l(2)glts3

numb[+]/numb2 is an enhancer of tormogen cell phenotype of l(2)glts3

numb[+]/numb2 is an enhancer of external sensory organ phenotype of l(2)glts3

NOT Enhancer of
Suppressor of
Statement
Reference

numb[+]/numb2 is a suppressor | partially of ommatidium | male phenotype of dsh1

Df(1)N-81k1, numb[+], numb2, + is a suppressor | partially of wing phenotype of Scer\GAL4nub-AC-62, spdoUAS.cOa

Other
Additional Comments
Genetic Interactions
Statement
Reference

Klp98AΔ47/+;numb2/numbSW or Klp98AΔ47/+;numbSW/numb15 mutants have a multiple socket phenotype on the notum; this phenotype is suppressed in Klp98AΔ47/Klp98AΔ6;numb2/numbSW, Klp98AΔ47/Klp98AΔ8;numb2/numbSW or Klp98AΔ47/Klp98AΔ6;numb15/numbSW double mutants.

Expression of spdoScer\UAS.cOa under the control of Scer\GAL4twi.PG in a numb2 mutant embryo blocks the formation of svp-positive precursor cells, resulting in dramatically fewer svp-positive heart cells and less cardioblasts. Fewer svp-negative cardioblasts develop.

eve-positive equivalence groups form but less eve-positive pericardial cells are seen when spdoScer\UAS.cOa is expressed under the control of Scer\GAL4twi.PG in a numb2 background.

Expression of NScer\UAS.cBa under the control of Scer\GAL4twi.PG in a numb2 and spdoG104 mutant background increases the number of eve-positive pericardial cells, and decreases the number of eve-positive DA1 muscle numbers compared to embryos mutant for spdoG104. However, there is no change observed in this increased number of eve-positive pericardial cells between spdoG104 embryos also expressing NScer\UAS.cBa under the control of Scer\GAL4twi.PG alone, or in combination with numb2.

Expression of fngScer\UAS.cKa under the control of Scer\GAL4twi.PG in a numb2 and spdoG104 mutant background increases the number of eve-positive pericardial cells, and decreases the number of eve-positive DA1 muscle numbers compared to embryos mutant for spdoG104. However, there is no change observed in this increased number of eve-positive pericardial cells between spdoG104 embryos also expressing fngScer\UAS.cKa under the control of Scer\GAL4twi.PG alone, or in combination with numb2.

Simultaneously expressing spdoScer\UAS.cOa under the control of Scer\GAL4nub-AC-62 in a Df(1)N-81k1/+ and numb2/+ background partially suppresses wing notching, vein thickening, and reduced wing size observed in the absence of numb2.

There is a slightly reduced number of ectopic scutellar bristles in flies expressing spdoScer\UAS.cOa under the control of Scer\GAL4nub-AC-62 in a numb2/+ background.

Expression of spdoScer\UAS.cOa under the control of Scer\GAL4twi.PG in the presence of numb2/+ suppresses the formation of extra svp-positive heart precursors by stage 12, and extra progenitor svp-positive pericardial cells, to almost wildtype levels.

Clones induced

Large numb2 clones in the head of WASp1/Df(3R)3450 animals rarely show the numb2 multiple socket phenotype, while the WASp1/Df(3R)3450 smooth cuticle phenotype predominates, indicating that WASp is epistatic to numb.

In Rca133X16, numb2 double mutants the GMC4-2a ganglion mother cell fails to divide and adopts the RP2sib neuron fate in about 1 in 2 cases. In Rca133X16, numb2 double mutants the GMC1-1a ganglion mother cell fails to divide and adopts the pCC neuron fate in about 3/4 of cases. In Rca133X16, numb2 double mutants the ganglion mother cell that normally mothers the U/CQ and U/CQ sibling neurons fails to divide and often adopts the U/CQ sibling neuron fate.

Su(H)8 mutation dominantly suppresses the double socket phenotype, but not the double sheath phenotype, of numbSW/numb2 mutants. Double mutant clones (numb2 Su(H)8) exhibit the phenotype caused due to loss of function of Su(H) alone: twinned hair phenotype.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Fails to complement
Partially rescued by
Comments
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
Comments
Comments

On the basis of CNS phenotype numb alleles form a series: numb2 > numb4 > numb1/numb3.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
References (34)