FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Allele: Dmel\Abd-BUab-1
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General Information
Symbol
Dmel\Abd-BUab-1
Species
D. melanogaster
Name
FlyBase ID
FBal0000149
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Uab1, Uab
Key Links
Nature of the Allele
Progenitor genotype
Caused by aberration
Cytology

Polytene chromosomes normal.

Description

Small inversion.

Cytologically normal inversion with breakpoints at coordinates -14kb and 185kb.

Breakpoints in the 'bxd' and Abd-B(r) transcription units (FBrf0042053). The abd-A and Abd-B transcription units are inverted with respect to Ubx.

-14 kb; +185 kb inverted.

Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Variant Molecular Consequences
Associated Sequence Data
DNA sequence
Protein sequence
 
Expression Data
Reporter Expression
Additional Information
Statement
Reference

Abd-B is ectopically expressed strongly in single cells or in small patches of cells in the epidermis and the ventral nerve cord in abdominal segments 1-4. Patches of strongly expressing cells are also visible in the normal Abd-B expression domain and are particularly conspicuous in parasegments 10 and 11 which normally express Abd-B weakly.

 
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

In Abd-BM1/Abd-BUab-1 embryos, the genital disc primordium is disorganised and contains about eight cells. Abd-BUab-1 mitotic recombination clones induced in the larval stages exhibit normal analia in both sexes and in the external female structure. In the main genitalia, there are two types of clone: some of them, probably induced in the internal genitalia, transform genital structures into distal leg or, less frequently, antenna. By contrast, clones in the lateral plates or clasper teeth are wild-type or cause only slight pattern alterations. Clones induced in the male A9 segment have smooth borders and are located mostly in the penis apparatus presumptive region. Clones in other regions are, in general, indented. Abd-Biab9-x23-1/Abd-BUab-1 male flies lack internal genitalia, while female genitalia is abnormal. A common feature of these females is the absence of parovaria, and in about half of these, three or even four spermathecae instead of the normal two are observed. Supernumerary spermathecae are also detected in Abd-Biab9-x23-1/Abd-BUab-1 clones. In a few females, duplications of part of the internal genitalia are observed.

In stage 15 Abd-BUab-1 embryos, segment A9 is transformed to an A8-like segment. Abd-BUab-1 embryos have the same number of genital disc precursor cells as wild-type embryos, but these cells are aberrantly arranged into two rows, with a gap in the middle, that are connected at their lateral tips. In Abd-Biab8-D14/Abd-BUab-1 mutant embryos, segments A5 to A9 are transformed into more anterior-like segments and most genital disc precursor cells are missing, leaving just ~7 present instead of the wild-type number of 22.

Male and female abdominal segment are normal, genitalia and analia are missing.

Adult homozygous males have 6 normal abdominal segments. Males and females lack genitalia. Enhances penetrance of head defect phenotype when in trans with Abd-Biab9-tuh-3. Heterozygotes with Abd-Biab9-tuh-3 exhibit genital defects to a moderate degree.

The Abd-BUab-1 leg transformation is epistatic to the Ubxbxd-51j transformation.

Male and female genitalia and analia are missing or abnormal in homozygotes. Parasegment 14 is partially transformed into parasegment 13, and there is a rudimentary setal belt in A9 in homozygous embryos. Also shows dominant gain-of-function phenotypes.

Causes A1 to transform toward A2.

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

Complements iab-5 and iab-6 alleles.

Images (0)
Mutant
Wild-type
Stocks (2)
Notes on Origin
Discoverer

Lewis.

E. B. Lewis.

Comments
Comments

Reversion studies show that Abd-BUab-1 causes abnormal expression of abd-A domain functions in A1.

m+ r- mutant.

Abd-B m+r- mutation.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (9)
References (24)