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General Information
Symbol
Dmel\pbl3
Species
D. melanogaster
Name
FlyBase ID
FBal0013547
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
pbl70
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
point mutation
Nucleotide change:

G7901808A

Reported nucleotide change:

G?A

Amino acid change:

W185term | pbl-PA; W185term | pbl-PB; W114term | pbl-PC; W114term | pbl-PD; W232term | pbl-PE

Reported amino acid change:

W185term

Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference

Mutation results in premature termination in the C-terminal end of the first BRCT domain.

Nucleotide substitution: G?A.

Amino acid replacement: W185term.

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 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Zygotic mutant embryos show pleiotropic effects on mesoderm development that disrupt gastrulation, and a consistent replacement of denticles with ectopic naked cuticle on the ventral side.

Homozygous stage 13 embryos show defects in the left-right asymmetry in their hindgut, with some embryos show no asymmetry, and others showing inverse asymmetry.

85.1 +/- 3.8% of cells in the epidermis of stage 10 pbl2/pbl3 embryos are binucleate, indicating a failure in cytokinesis.

pbl3 homozygous embryos display defects in cytokinesis and mesodermal migration (a reduction in the number of eve-positive hemisegments compared to wild-type). Mesodermal invagination is unaffected.

pbl3 mutants exhibit an increase in centrosome number to four during the cycle following a cytokinesis failure.

Contact between the invaginated mesoderm and the ectoderm does not occur in homozygous embryos.

Both pbl3/pbl3 and pbl3/Df(3L)pbl-NR embryos have dramatically reduced numbers of eve positive mesodermal cells at the extended germband stage. While the mesoderm invaginates as normal in these embryos, cells at the base of the invaginated mesodermal tube fail to attach to the underlying ectoderm. Post-invagination migration of the mesoderm and the characteristic cell shape changes that accompany it also fail. Close analysis of the mesoderm during the stages when migration normally occurs reveals a filamentous actin rich cell cortex equally distributed round the circumference of the cells, with none of the protrusions found in wild-type present. As in wild-type mesoderm, adherens junctions are lost from the mesoderm in pbl3 homozygotes after invagination. At stages 10-12, embryos homozygous for pbl3 have an average of just 1 hemisegment with eve expressing mesoderm cells, compared with 22 wild-type embryos. Defects in cytokinesis in pbl3 homozygous embryos lead to the formation of multinucleate cells. This phenotype is fully penetrant.

pbl2/pbl3 embryos develop abnormal visceral mesoderm and somatic musculature. The visceral mesoderm no longer forms a continuous band running along the anterior to posterior axis on each side of the embryo and the fibres of the somatic musculature are irregular in structure. Segmentally repeated clusters of eve-positive dorsal mesodermal cells normally seen in stage 11 embryos fail to form. Mesodermal abnormalities in pbl2/pbl3 embryos may be due in part to a failure of migration of the dorsal mesoderm: During stage 8, migrating mesodermal cells in these embryos have fewer protrusions in the direction of motion, are more rounded more closely packed together. This is particularly clear for those cells adjacent to the ectoderm. In most of these embryos at stage 10, mesodermal cells have failed to migrate to a position adjacent to the dorsal-most ectodermal cells or to form a monolayer under the ectoderm, instead remaining aggregated around the ventral midline.

In mutant embryos, large multinucleated cells with NB6-4 identity appear in 92% of thoracic hemisegments. these cells have 3.4 nuclei on average (In wild-type NB6-4T divides into 5 to 6 cells). In contrast, cells with NB6-4A identity are present in only a small percentage of abdominal hemisegments (In wild-type NB6-4A divides into 2 cells). Many of these cells have two nuclei.

Cytokinesis, but not cell progression, is prevented. Sense organ precursors differentiate predominantly into md neurons.

Nuclei reduced in number and exhibit gross morphological alterations. Cells are multinucleate and may have more than one spindle after postblastoderm mitoses.

Cytokinesis fails although cellularization and nuclear aspects of mitosis are normal.

cold-sensitive

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
NOT Enhanced by
Statement
Reference

pbl3 has mitotic cell cycle defective phenotype, non-enhanceable by pimIL

Suppressed by
NOT suppressed by
NOT Enhancer of
Statement
Reference

pbl3 is a non-enhancer of cytokinesis defective phenotype of pimIL

pbl3 is a non-enhancer of mitotic cell cycle defective phenotype of pimIL

Suppressor of
Statement
Reference
Phenotype Manifest In
NOT Enhanced by
Statement
Reference

pbl3 has centrosome phenotype, non-enhanceable by pimIL

Suppressed by
NOT suppressed by
Statement
Reference

pbl3 has mesoderm phenotype, non-suppressible by stg4/stg4

pbl3 has mesoderm phenotype, non-suppressible by htlUAS.cMa/Scer\GAL4twi.PB

Enhancer of
Statement
Reference

pbl[+]/pbl3 is an enhancer of embryonic peripheral nervous system & neuron phenotype of stiGS9053/Df(3L)iro-2

NOT Enhancer of
Statement
Reference

pbl[+]/pbl3 is a non-enhancer of eye phenotype of Hsap\MECP2Δ166.UAS, Scer\GAL4GMR.PU

pbl3 is a non-enhancer of centrosome phenotype of pimIL

Suppressor of
Statement
Reference

pbl[+]/pbl3 is a suppressor of eye phenotype of Hsap\MECP2UAS.FL, Scer\GAL4GMR.PU

pbl3 is a suppressor of eye phenotype of Rho1GMR.PH

NOT Suppressor of
Statement
Reference

pbl[+]/pbl3 is a non-suppressor of eye phenotype of Hsap\MECP2Δ166.UAS, Scer\GAL4GMR.PU

Additional Comments
Genetic Interactions
Statement
Reference

Expression of Rac1V12.Scer\UAS under the control of Scer\GAL4twi.PU partially rescues mesodermal cell morphology in pbl2/pbl3 embryos: cellular protrusions are restored, but the defect in cell rounding is not rescued.

Expression of Cdc42V12.Scer\UAS under the control of Scer\GAL4twi.PU partially rescues mesodermal cell morphology in pbl2/pbl3 embryos: cellular protrusions are restored (although they appear larger and more elaborate than normal), but the defect in cell rounding is not rescued.

Expression of Rho1V14.Scer\UAS under the control of Scer\GAL4twi.PU partially rescues mesodermal cell morphology in pbl2/pbl3 embryos: cellular protrusions are not restored, but the defect in cell rounding is rescued.

Co-expression of Rac1Scer\UAS.cLa enhances the partial rescue of pbl3 mesodermal migration defects seen when pblΔBRCT.Scer\UAS.T:Hsap\MYC is expressed under the control of Scer\GAL4twi.2PE.

Co-expression of Rho1Scer\UAS.cMa does not enhance the partial rescue of pbl3 mesodermal migration defects seen when pblΔBRCT.Scer\UAS.T:Hsap\MYC is expressed under the control of Scer\GAL4twi.2PE.

pimIL pbl3 double mutants exhibit an increase in centrosome number per cell per cycle.

The formation of multinucleate cells in pbl3 homozygous embryos is suppressed by stg4/stg4, but the failure of mesoderm migration and its accompanying cell shape changes is not. Both mesoderm spreading and differentiation in pbl3 homozygous embryos are partially rescued by htlScer\UAS.T:λ\cI-DD; Scer\GAL4twi.PB, but not by htlScer\UAS.cMa; Scer\GAL4twi.PB.

Acts as a dominant suppressor of the Rho1GMR.PH-induced rough eye phenotype.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Partially rescues
Comments

Scer\GAL4twi.PG-mediated expression of pblScer\UAS.T:Ivir\HA1 rescues the mesoderm defects in pbl3 embryos but the ectopic naked cuticle phenotype persists.

Expression of pblΔPH.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4prd.RG1 substantially rescues the failure of cytokinesis seen in the epidermis of stage 10 pbl2/pbl3 embryos.

pbl2/pbl3 embryos rescued with two copies of pbl+tcos34 show no defects in cytokinesis or mesoderm migration and develop into viable and fertile adults.

Two copies of pblΔPH partially rescue the failure of cytokinesis seen in stage 10 pbl2/pbl3 embryos: only 54.6 +/- 4.5% of the epidermal cells are binucleate in the rescued embryos.

The defects in mesoderm development seen in pbl2/pbl3 embryos are not completely rescued by two copies of pblΔPH : the failure of the invaginated mesodermal tube to flatten down onto the ectoderm is not rescued by pblΔPH, while the number of protrusions on the mesodermal cells during the migration period between the first and second rounds of mitosis appears slightly increased and the failure of rounding of mesodermal cells is partially rescued.

A pbl3/+ background partially rescues the eye phenotype seen when pblDH-PH.Scer\UAS.T:Ivir\HA1 is expressed under the control of Scer\GAL4GMR.PU.

Expression of pblΔBRCT.Scer\UAS.T:Hsap\MYC under the control of Scer\GAL4twi.2PE partially rescues the mesodermal migration defects seen in pbl3 homozygous mutants but is unable to rescue the cytokinesis defects.

Expression of pblΔN-term.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE fails to rescue the mesodermal migration defects seen in pbl3 homozygous mutants.

Expression of pblScer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE rescues the cytokinesis and mesodermal migration defects seen in pbl3 homozygous mutants.

Expression of pblDH-PH.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE rescues the mesodermal migration defects seen in pbl3 homozygous mutants.

Expression of pblDH.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE fails to rescue the mesodermal migration defects seen in pbl3 homozygous mutants.

Expression of pblΔC-term.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE partially rescues the mesodermal migration defects seen in pbl3 homozygous mutants but is unable to rescue the cytokinesis defects.

Expression of pblDH-PH-V531D.Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4twi.2PE fails to rescue the mesodermal migration defects seen in pbl3 homozygous mutants.

Both cytokinesis and migration defects in the mesoderm of pbl3/Df(3L)pbl-NR embryos are rescued by pblScer\UAS.cPa; Scer\GAL4twi.PB. However, cytokinesis defects still result in multi-nucleated cells in the ectoderm of these embryos.

Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (5)
References (24)