FB2025_01 , released February 20, 2025
Allele: Dmel\pb20
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General Information
Symbol
Dmel\pb20
Species
D. melanogaster
Name
FlyBase ID
FBal0013524
Feature type
allele
Associated gene
Dmel\pb
Associated Insertion(s)
Carried in Construct
Key Links
Allele class

amorphic allele - genetic evidence

Mutagen
Nature of the Allele
Allele class

amorphic allele - genetic evidence

(Cribbs et al., 1992)
Mutagen
X ray
Progenitor genotype
Caused by aberration
Df(3R)MAP2
Cytology
Description
Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Variant Molecular Consequences
Associated Sequence Data
DDBJ / EMBL / GenBank
DNA sequence
Protein sequence
 
UniProtKB/Swiss-Prot
    UniProtKB/TrEMBL
      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

      arista | ectopic (with pb4)

      (Tayyab et al., 2004)

      arista | ectopic (with pb11)

      (Tayyab et al., 2004)

      arista | ectopic (with pb13)

      (Tayyab et al., 2004)

      arista | ectopic (with pb18)

      (Tayyab et al., 2004)

      arista | ectopic | heat sensitive (with pb27), with pbQ50K.hs

      (Percival-Smith et al., 1997)

      arista | ectopic | temperature conditional (with pb1)

      (Tayyab et al., 2004)

      labellar cap (with pb2)

      (Tayyab et al., 2004)

      labellar cap (with pb4)

      (Tayyab et al., 2004)

      labellar cap (with pb5)

      (Tayyab et al., 2004)

      labellar cap (with pb10)

      (Tayyab et al., 2004)

      labellar cap (with pb13)

      (Tayyab et al., 2004)

      labellar cap (with pb14)

      (Tayyab et al., 2004)

      labellar cap (with pb35)

      (Tayyab et al., 2004)

      labellar cap (with pb40)

      (Tayyab et al., 2004)

      labellum

      (Cribbs et al., 1992)

      maxillary palp

      (Percival-Smith and Bondy, 1999, Percival-Smith et al., 1997)

      maxillary palp (with pb1)

      (Tayyab et al., 2004)

      maxillary palp (with pb2)

      (Tayyab et al., 2004)

      maxillary palp (with pb3)

      (Tayyab et al., 2004)

      maxillary palp (with pb4)

      (Tayyab et al., 2004)

      maxillary palp (with pb5)

      (Tayyab et al., 2004)

      maxillary palp (with pb10)

      (Tayyab et al., 2004)

      maxillary palp (with pb11)

      (Tayyab et al., 2004)

      maxillary palp (with pb13)

      (Tayyab et al., 2004)

      maxillary palp (with pb14)

      (Tayyab et al., 2004)

      maxillary palp (with pb18)

      (Tayyab et al., 2004)

      maxillary palp (with pb27)

      (Percival-Smith et al., 2013)

      maxillary palp (with pb35)

      (Tayyab et al., 2004)

      maxillary palp (with pb40)

      (Tayyab et al., 2004)

      proboscis

      (Percival-Smith and Bondy, 1999)

      proboscis (with pb3)

      (Tayyab et al., 2004)

      proboscis (with pb11)

      (Tayyab et al., 2004)

      proboscis (with pb18)

      (Tayyab et al., 2004)

      proboscis | temperature conditional (with pb1)

      (Tayyab et al., 2004)

      pseudotrachea (with pb2)

      (Tayyab et al., 2004)

      pseudotrachea (with pb3)

      (Tayyab et al., 2004)

      pseudotrachea (with pb4)

      (Tayyab et al., 2004)

      pseudotrachea (with pb5)

      (Tayyab et al., 2004)

      pseudotrachea (with pb10)

      (Tayyab et al., 2004)

      pseudotrachea (with pb11)

      (Tayyab et al., 2004)

      pseudotrachea (with pb13)

      (Tayyab et al., 2004)

      pseudotrachea (with pb14)

      (Tayyab et al., 2004)

      pseudotrachea (with pb18)

      (Tayyab et al., 2004)

      pseudotrachea (with pb35)

      (Tayyab et al., 2004)

      pseudotrachea (with pb40)

      (Tayyab et al., 2004)

      pseudotrachea | heat sensitive (with pb1)

      (Tayyab et al., 2004)

      pulvillus | ectopic (with pb35)

      (Tayyab et al., 2004)

      pulvillus | ectopic (with pb40)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb2)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb3)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb5)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb10)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb14)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb18)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb35)

      (Tayyab et al., 2004)

      tarsal segment | ectopic (with pb40)

      (Tayyab et al., 2004)

      tarsal segment | ectopic | temperature conditional (with pb1)

      (Tayyab et al., 2004)

      unguis | ectopic (with pb35)

      (Tayyab et al., 2004)

      unguis | ectopic (with pb40)

      (Tayyab et al., 2004)
      Detailed Description
      Statement
      Reference

      The maxillary palps of pb27/pb20 mutant flies are reduced to vestigial stumps.

      (Percival-Smith et al., 2013)

      pb1/pb20 flies raised at 23 or 29[o]C have a null mutant phenotype; the maxillary palps are vestigial, the proboscis is transformed into a pair of tarsi and the pseudotracheae are missing. pb1/pb20 flies raised at 18[o]C have a hypomorphic phenotype; the maxillary palps are vestigial, the proboscis is transformed into a pair of aristae, and the number of pseudotracheal rows is reduced to one or two.

      pb2/pb20, pb5/pb20, pb10/pb20 and pb14/pb20 flies have vestigial maxillary palps, the labellar caps are fully transformed to tarsi and the pseudotracheae are missing.

      pb3/pb20 flies have a null mutant phenotype; the maxillary palps are vestigial, the proboscis is transformed into tarsi and the pseudotracheae are missing.

      pb4/pb20 flies show a reduction in length of the maxillary palps, the labellar cap is transformed to an arista and the number of pseudotracheal rows is reduced to 1 or 2.

      pb11/pb20 flies have a hypomorphic phenotype; the maxillary palps are reduced, the proboscis is transformed into aristae, and the number of pseudotracheal rows is reduced to two to three.

      pb13/pb20 flies show a reduction in length of the maxillary palps, the labellar cap is weakly transformed towards an arista and the number of pseudotracheal rows is reduced to 3 or 4.

      pb18/pb20 flies have a hypomorphic phenotype; the maxillary palps are vestigial, the proboscis is transformed into aristae or tarsi, and the number of pseudotracheal rows is reduced to one or two.

      pb35/pb20 flies have vestigial maxillary palps, the labellar caps are weakly transformed to tarsi (claws and pulvilli form, but the tarsi are short and stumpy and sometimes arista-like structures are observed) and the pseudotracheae are missing.

      pb40/pb20 flies have vestigial maxillary palps, the labellar caps are weakly transformed to tarsi (claws and pulvilli form, but the tarsi are short and stumpy and sometimes arista-like structures are observed) and the number of pseudotracheal rows is reduced to 0 to 1.

      (Tayyab et al., 2004)

      pb27/pb20 flies have reduced maxillary palps and a proboscis to tarsus transformation.

      (Percival-Smith and Bondy, 1999)

      pb27/pb20 hemizygotes exhibit reduced maxillary palps. Heat induced expression of pbQ50K.hs in pb27/pb20 mutants at 36.5oC for 15-30 minutes between 67 and 72 hours AEL transforms the tarsal mouthparts to arista. Transformation is not associated with pseudotrachea formation. Clones of pbαTub84B.PP in pb27/pb20 mutants exhibit rescue of the pb null phenotype: the antenna is transformed to a maxillary palp, the reduced maxillary palp is rescued and the tarsal mouthparts are rescued to a proboscis. Clones of pbQ50K.αTub84B in pb27/pb20 mutants display antenna that are not transformed to maxillary palps, the reduced maxillary palps are not rescued and the tarsal mouthparts are transformed towards antenna. Clones of pb27 Scr2 cells in the ectoderm (proboscis precursor cells) of pb27/pb20 mutants adopt tarsal identity and not aristal identity as in a pb+ organism.

      (Percival-Smith et al., 1997)

      The labial palp is transformed to prothoracic leg.

      (Cribbs et al., 1992)

      leg

      External Data
      Interactions
      Show genetic interaction network for Enhancers & Suppressors
      Phenotypic Class
      Phenotype Manifest In
      Additional Comments
      Genetic Interactions
      Statement
      Reference

      Expression of ScrScer\UAS.cPb under the control of Scer\GAL4pb.PJ does not suppress the vestigial maxillary palp phenotype seen in pb27/pb20 mutant flies.

      Expression of ScrScer\UAS.cPb under the control of Scer\GAL4pb.PJ in a pb27/pb20 mutant background results in a normal antenna.

      Expression of ScrΔDYTQL.CTD.Scer\UAS under the control of Scer\GAL4pb.PJ in a pb27/pb20 mutant background results in an antenna to proboscis transformation: deformed antennae with patches of tricombless, convoluted cuticle are seen. Tricombless cuticle is also seen in the pb27/pb20 mutant vestigial maxillary palp. No evidence of a labial cap and chemosensory bristles is observed in theses patches of tricombless cuticle.

      Expression of ScrΔLASCY.DYTQL.Scer\UAS under the control of Scer\GAL4pb.PJ in a pb27/pb20 mutant background results in an antenna to proboscis transformation: deformed antennae with patches of tricombless, convoluted cuticle are seen. Tricombless cuticle is also seen in the pb27/pb20 mutant vestigial maxillary palp. No evidence of a labial cap and chemosensory bristles is observed in theses patches of tricombless cuticle.

      (Percival-Smith et al., 2013)
      Xenogenetic Interactions
      Statement
      Reference

      The pb27/pb20 reduced maxillary palp phenotype is not rescued by expression of Mmus\Hoxa2αTub84B.PP and the proboscis to tarsus transformation is replaced with a partial transformation of proboscis to arista in these flies.

      (Percival-Smith and Bondy, 1999)
      Complementation and Rescue Data
      Rescued by

      pb27/pb20 is rescued by pbαTub84B.PP

      (Percival-Smith and Bondy, 1999)
      Comments
      Images (0)
      Mutant
      Wild-type
      Stocks (2)
      Notes on Origin
      Discoverer

      Pultz.

      External Crossreferences and Linkouts ( 0 )
      Synonyms and Secondary IDs (4)
      Reported As
      Symbol Synonym
      map2
      (Cribbs et al., 1992)
      pb20
      (Jordan et al., 2002)
      pb20
      (Percival-Smith et al., 2013, Tayyab et al., 2004)
      pbmap2
      Name Synonyms
      Secondary FlyBase IDs
        References (7)