FB2026_02 , released June 18, 2026
Allele: Dmel\btlLG18
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General Information
Symbol
Dmel\btlLG18
Species
D. melanogaster
Name
FlyBase ID
FBal0030666
Feature type
allele
Associated gene
Dmel\btl
Associated Insertion(s)
Carried in Construct
Key Links
Allele class

amorphic allele - genetic evidence

loss of function allele

Mutagen
Nature of the Allele
Allele class

amorphic allele - genetic evidence

(Sutherland et al., 1996, Klambt et al., 1992)

loss of function allele

(Samakovlis et al., 1996)
Mutagen
ethyl methanesulfonate
(Burmester et al., 2000, Klambt et al., 1992)
Progenitor genotype
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
      Detailed Description
      Statement
      Reference

      btlLG18 homozygous clones in the dorsal air sac primordium grow and divide normally but never contribute to the tip of the primordium.

      (Cabernard and Affolter, 2005)

      Tracheal pits form, but tracheal cells do not undergo significant migration, and remain clustered at the site of the tracheal pit. Posterior pair of midline glia cells begin to migrate anteriorly, but fail to reach posterior commisure. This phenotype only evident in midline glia cells, even though btl expressed in several midline cell types.

      (Klambt et al., 1992)
      External Data
      Interactions
      Show genetic interaction network for Enhancers & Suppressors
      Phenotypic Class
      Phenotype Manifest In
      Other
      Additional Comments
      Genetic Interactions
      Statement
      Reference

      stumps09904b/btlLG18 double heterozygotes did not show any tracheal defects.

      (Imam et al., 1999)

      btlLG18 bnl00857 double mutants exhibit a tracheal phenotype similar to either mutant alone.

      (Sutherland et al., 1996)
      Xenogenetic Interactions
      Statement
      Reference
      Complementation and Rescue Data
      Images (0)
      Mutant
      Wild-type
      Stocks (0)
      Notes on Origin
      Discoverer
      Comments
      Comments

      Isolated on basis of lethality over Df(3L)fz-GF3b and Df(3L)fz-GS1a. Phenotype of homozygote indistinguishable from phenotype of heterozygote with Df(3L)fz-GF3b or Df(3L)fz-GS1a. The btl alleles form a phenotypic series with respect to the tracheal phenotype. In decreasing order of severity, btlLG18 = btlLG19 > btlH82Δ3 > btlH82Δ11 > btl6-81Δ1.

      (Klambt et al., 1992)
      External Crossreferences and Linkouts ( 0 )
      Synonyms and Secondary IDs (2)
      Reported As
      Symbol Synonym
      btlLG18
      (Peterson and Krasnow, 2015, Ghabrial et al., 2011, Ghabrial and Krasnow, 2006, Cabernard and Affolter, 2005)
      l(3)LG18
      (Burmester et al., 2000)
      Name Synonyms
      Secondary FlyBase IDs
        References (9)