Open Close
General Information
Symbol
Dmel\pb
Species
D. melanogaster
Name
proboscipedia
Annotation Symbol
CG31481
Feature Type
FlyBase ID
FBgn0051481
Gene Model Status
Stock Availability
Gene Snapshot
proboscipedia (pb) encodes a conserved homeodomain transcription factor. Its role in regional head development, from insects to mammals, likely involves combinatorial regulation both of cell-specific targets and of multiple signaling pathways. [Date last reviewed: 2019-03-14]
Also Known As

l(3)04498, proposcipedia

Key Links
Genomic Location
Cytogenetic map
Sequence location
3R:6,707,800..6,742,063 [-]
Recombination map

3-48

RefSeq locus
NT_033777 REGION:6707800..6742063
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
Belongs to the Antp homeobox family. Proboscipedia subfamily. (P31264)
Summaries
Gene Group (FlyBase)
ANTENNAPEDIA COMPLEX -
The Antennapedia complex (ANT-C) is one of two Hox gene complexes. Hox genes encode homeodomain transcription factors. ANT-C controls the identity of segments that contribute to the head and the anterior thorax. ANT-C homeotic genes show colinearity in their expression patterns with the exception of pb. (Adapted from FBrf0190304).
HOX-LIKE HOMEOBOX TRANSCRIPTION FACTORS -
HOX-like (HOXL) homeobox transcription factors are sequence-specific DNA binding proteins that regulate transcription. They encompass transcription factors encoded by the Hox genes of the Antennapedia and the Bithorax gene complexes and genes closely related in sequence. HOXL transcription factors are major regulators of animal development. (Adapted from FBrf0232555).
Protein Function (UniProtKB)
Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Controls development of mouthparts, and labial and maxillary palps.
(UniProt, P31264)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
pb: proboscipedia
Null alleles transform the labial palps of the adult into portions of the prothoracic leg. The distal tarsal segments are present, including claws and pulvilli. The distal portion of the first tarsal segment including the sex comb in males is fused directly to the proximal portion of the femur. Thus proximal first tarsus, tibia, and distal femur are absent. Leg segments proximal to femur are not present. Hypomorphic alleles produce a labial-palp-to-antenna transformation. Generally only more distal (arista) antennal structures are seen. Extremely weak hypomorphic alleles exist which produce no ostensible phenotype as homozygotes but do reveal a weak antennal transformation in combination with a deletion or null allele. Both null and hypomorphic alleles also show an alteration in maxillary palp morphology which has been interpreted as a transformation toward an antennal identity.
Summary (Interactive Fly)

transcription factor - homeodomain - Antp class - required for the formation of labial and maxillary palps - represses leg development in proboscis there is a non-cell autonomous requirement of Proboscipedia for growth and differentiation of the distal maxillary palp during metamorphosis

Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
4

Please see the GBrowse view of Dmel\pb or the JBrowse view of Dmel\pb for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Comments on Gene Model

Gene model reviewed during 5.50

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0089276
3728
782
FBtr0089277
3713
777
FBtr0089278
3713
777
FBtr0089279
3698
772
Additional Transcript Data and Comments
Reported size (kB)

4.3 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0088333
83.7
782
6.63
FBpp0088334
83.2
777
6.77
FBpp0088335
83.2
777
6.68
FBpp0088336
82.7
772
6.72
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)

798, 793, 788 (aa)

Comments
External Data
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\pb using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Gene Ontology (7 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518688
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN002518688
(assigned by GO_Central )
Biological Process (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518688
(assigned by GO_Central )
Cellular Component (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN002518688
(assigned by GO_Central )
Expression Data
Expression Summary Ribbons
Colored tiles in ribbon indicate that expression data has been curated by FlyBase for that anatomical location. Colorless tiles indicate that there is no curated data for that location.
For complete stage-specific expression data, view the modENCODE Development RNA-Seq section under High-Throughput Expression below.
Transcript Expression
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

bp transcripts are first detected in 2-4hr embryos, peak 6-8hr embryos, and diminish toward the end of embryogenesis. In larvae, they are most abundant at the second instar stage. They are detected throughout the pupal period with peak in the second 12 hours of pupal development. They are not detected in adults.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mesoderm

Comment: reference states 6 hr AEL

stomodeum | posterior to

Comment: reference states 6 hr AEL

Additional Descriptive Data

Antp P1 control causes ectopic expression of pb in the ventral nerve cord of the posterior prothorax, mesothorax and metathorax in a pattern that closely resembles that of wild type Antp protein. Spatially correct but reduced pb protein expression is also observed.

pb protein expression was assayed with antibodies to a pb/lacZ fusion protein. pb protein is first detected between 5.5 and 6hrs in a group of nuclei in the presumptive mesoderm behind the stomodeum. pb protein expression in the mesoderm is dynamic and the expressing cells migrate away from the ventral midline, separating into two groups. After hour 7, expression is observed in 6-8 cells internal to each manidibular lobe. Subsequently, staining is observed in a group of cells that become positioned along the walls of the foregut. Staining is also observed in the labial and maxillary lobes. By the end of germ band retraction, staining in the labial lobes and sternal region is quite intense. Staining in the maxillary and mandibular lobes has also become intense. By about 10hrs, staining is also observed in a group of cells in the vicinity of the posterior foregut which are later found around the esophagus and proventriculus. Expression in the gnathal segments remains strong during head involution. pb protein begins to be expressed in the CNS in a pattern that becomes increasingly complex. It is expressed in a subset of cells in the supraesophageal ganglion, the subesophageal ganglion, and in the ventral nerve cord. Distinct patterns of pb expression are observed in the CNS of the thoracic segments, the first six abdominal segments, and the more posterior abdominal segments.

Marker for
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\pb in GBrowse 2
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 50 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 43 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of pb
Transgenic constructs containing regulatory region of pb
Deletions and Duplications ( 43 )
Partially disrupted in
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
macrochaeta & prementum
microchaeta & wing
proboscis & sex comb | ectopic
prothoracic leg & sex comb
sex comb & prothoracic leg | conditional ts
tarsal segment & mouthpart
tarsal segment & mouthpart | conditional ts, with pb20, pb27
tarsal segment & mouthpart | conditional ts, with pb20, pbQ50K.hs
tarsal segment & mouthpart | conditional ts, with pb27, pbQ50K.hs
tarsal segment & mouthpart | conditional ts, with pb27/pb20
tarsal segment & mouthpart | conditional ts (with pb20), with pbQ50K.hs
tarsal segment & mouthpart | conditional ts (with pb27), with pbQ50K.hs
wing & macrochaeta, with Scer\GAL4dpp.blk1
wing vein L3 & macrochaeta
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (31)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
 
8 of 15
Yes
Yes
 
2 of 15
No
No
2 of 15
No
No
2 of 15
No
No
2 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (30)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
 
8 of 15
Yes
Yes
2 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
 
1 of 15
No
No
 
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Rattus norvegicus (Norway rat) (35)
7 of 13
Yes
Yes
6 of 13
No
Yes
2 of 13
No
No
2 of 13
No
Yes
2 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Xenopus tropicalis (Western clawed frog) (29)
6 of 12
Yes
Yes
5 of 12
No
Yes
2 of 12
No
Yes
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
Danio rerio (Zebrafish) (33)
8 of 15
Yes
Yes
8 of 15
Yes
Yes
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Caenorhabditis elegans (Nematode, roundworm) (8)
1 of 15
Yes
No
1 of 15
Yes
No
 
1 of 15
Yes
No
1 of 15
Yes
No
1 of 15
Yes
No
1 of 15
Yes
No
1 of 15
Yes
No
1 of 15
Yes
Yes
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (2)
1 of 15
Yes
Yes
1 of 15
Yes
No
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG091909O7 )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila suzukii
Spotted wing Drosophila
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG09150AD8 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W0BQY )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch butterfly
Heliconius melpomene
Postman butterfly
Apis florea
Little honeybee
Apis mellifera
Western honey bee
Bombus impatiens
Common eastern bumble bee
Bombus terrestris
Buff-tailed bumblebee
Linepithema humile
Argentine ant
Megachile rotundata
Alfalfa leafcutting bee
Nasonia vitripennis
Parasitic wasp
Dendroctonus ponderosae
Mountain pine beetle
Dendroctonus ponderosae
Mountain pine beetle
Dendroctonus ponderosae
Mountain pine beetle
Tribolium castaneum
Red flour beetle
Pediculus humanus
Human body louse
Rhodnius prolixus
Kissing bug
Cimex lectularius
Bed bug
Acyrthosiphon pisum
Pea aphid
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X0BOQ )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Ixodes scapularis
Black-legged tick
Stegodyphus mimosarum
African social velvet spider
Stegodyphus mimosarum
African social velvet spider
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G0IJ4 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (18)
3 of 10
3 of 10
3 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Model Summary Ribbon
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v7.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    Functional Complementation Data
    Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
    Interactions
    Summary of Physical Interactions
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    esyN Network Key:
    Suppression
    Enhancement

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    enhanceable
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    External Data
    Linkouts
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map

    3-48

    Cytogenetic map
    Sequence location
    3R:6,707,800..6,742,063 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    84A5-84A5
    Limits computationally determined from genome sequence between P{PZ}lab01241 and P{PZ}pb04498
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    84A4-84A5
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (30)
    Genomic Clones (40)
    cDNA Clones (17)
     

    Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequences
    BDGP DGC clones
      Other clones
        Drosophila Genomics Resource Center cDNA clones

        For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

          cDNA Clones, End Sequenced (ESTs)
          BDGP DGC clones
            Other clones
              RNAi and Array Information
              Linkouts
              DRSC - Results frm RNAi screens
              GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
              Antibody Information
              Laboratory Generated Antibodies
               
              Commercially Available Antibodies
               
              Other Information
              Relationship to Other Genes
              Source for database identify of
              Source for database merge of

              Source for merge of: pb l(3)04498

              Additional comments
              Other Comments

              Genetic analysis suggests that wild type pb functions to limit the response of wg to incoming hh signal.

              pb and ey have antagonistic roles in head development.

              Annotation CG17880 renamed CG31481 in release 3 of the genome annotation.

              Phenotypic analysis of double mutants implicates ct in the regulation of expression and/or function of Antp and pb.

              Loss of exd activity is epistatic to loss of pb activity or loss of pb and Scr activity.

              Ectopic expression of pb can alter the developmental program of adult legs into maxillary or labial palps. These homeotic transformations have equal effect on all three sets of legs. Molecular events occurring downstream of the establishment of compartment boundary are affected by ectopic pb expression in imaginal discs.

              Eye loss can be induced by pb protein that no longer effectively bind to DNA. The dose-sensitive eye loss thus appears to be mediated by specific, context-dependent protein-protein interactions.

              Ras85D is a positive modifier of pb activity, while the Ras85D-antagonist Gap1 has an opposite effect.

              Effects of overexpression of ANTP-C genes on tarsal segmentation in ss mutants is studied.

              Simultaneous removal of pb and Scr activity results in a proboscis-to-antenna transformation. Dominant negative pb molecules inhibit the activity of Scr indicating that pb and Scr interact in a multimeric protein complex in determination of proboscis identity. The absence of pb and Scr expression leads to antennal identity, expression of pb only leads to maxillary palp identity, expression of Scr only leads to tarsus identity and the expression of both pb and Scr leads to proboscis identity.

              A phylogenetic analysis of the Antp-class of homeodomains in nematode, Drosophila, amphioxus, mouse and human indicates that the 13 cognate group genes of this family can be divided into two major groups. Genes that are phylogenetically close are also closely located on the chromosome, suggesting that the colinearity between gene expression and gene arrangement was generated by successive tandem gene duplications and that the gene arrangement has been maintained by some sort of selection.

              pb is required for the formation of the adult mouthparts, labial and maxillary palps.

              Quantitative aspects of pb function are important in determining segmental identity, including cross regulatory events involved in this determination.

              A conserved region located in the second intron of pb is essential for proper formation of the adult mouthparts. The upstream DNA of pb appears to contain negative regulatory DNA required for silencing pb product accumulation in inappropriate domains of third instar imaginal discs.

              Sequences contained in a pb minigene are capable of suppressing a w marker located in a P-element vector. Regions of pb have been identified that are able to repress w gene in a manner that is sensitive to homolog pairing, pairing sensitive (PS) regions. These PS regions are important for the developmental regulation of pb.

              Experiments with heat shock constructs show that the pb product interacts with the Scr product.

              The homologs of Antp, ftz, Scr, Dfd, Ama, bcd, zen, pb and lab, but not zen2 are all present in D.pseudoobscura.pseudoobscura, in the same linear order and similarly spaced along the chromosome as in D.melanogaster.

              Comparative analysis of the homeobox sequences reveals the subdivision of the Antp-type homeobox genes into three classes early in metazoan evolution, one includes Abd-B, the second includes abd-A, Ubx, Antp, Scr, Dfd and ftz, and the third includes zen, zen2, pb and lab.

              A structural analysis of the pb transcriptional unit has been carried out.

              The pb protein is capable of participating in negative regulation of the more posteriorly expressed Antp, as well as serving a homeotic selector function in the head.

              Flies carrying a deletion of pb survive to adulthood and have a pb null phenotype.

              Null alleles transform the labial palps of the adult into portions of the prothoracic leg. The distal tarsal segments are present, including claws and pulvilli. The distal portion of the first tarsal segment including the sex comb in males is fused directly to the proximal portion of the femur. Thus proximal first tarsus, tibia and distal femur are absent. Leg segments proximal to femur are not present. Hypomorphic alleles produce a labial-palp-to-antenna transformation. Generally only more distal (arista) antennal structures are seen. Extremely weak hypomorphic alleles exist which produce no ostensible phenotype as homozygotes but do reveal a weak antennal transformation in combination with a deletion or null allele. Both null and hypomorphic alleles also show an alteration in maxillary palp morphology which has been interpreted as a transformation toward an antennal identity.

              Origin and Etymology
              Discoverer
              Etymology
              Identification
              External Crossreferences and Linkouts ( 51 )
              Sequence Crossreferences
              NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
              GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
              GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
              RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
              UniProt/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
              Other crossreferences
              BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
              Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
              Flygut - An atlas of the Drosophila adult midgut
              GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
              iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
              KEGG Genes - Molecular building blocks of life in the genomic space.
              modMine - A data warehouse for the modENCODE project
              Linkouts
              BioGRID - A database of protein and genetic interactions.
              DroID - A comprehensive database of gene and protein interactions.
              DRSC - Results frm RNAi screens
              FLIGHT - Cell culture data for RNAi and other high-throughput technologies
              FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
              FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
              FlyMine - An integrated database for Drosophila genomics
              Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
              InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
              MIST (genetic) - An integrated Molecular Interaction Database
              MIST (protein-protein) - An integrated Molecular Interaction Database
              Synonyms and Secondary IDs (14)
              Reported As
              Symbol Synonym
              BG:DS01719.1
              CG17880
              Secondary FlyBase IDs
              • FBgn0003040
              • FBgn0010841
              • FBgn0063631
              Datasets (0)
              Study focus (0)
              Experimental Role
              Project
              Project Type
              Title
              References (261)