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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Key Links
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
Additional Notes
Nucleotide change:


Reported nucleotide change:



A to T change in the AG splice acceptor of the 5' boundary of exon 4 of Idh3b.

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

A to T change in the AG splice acceptor of the 5' boundary of exon 4 of Idh3b.

Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

Idh3b1/Df(3R)Exel6188 transheterozygotes develop more slowly relative to controls as the time from egg-laying to puparium formation is significantly increased; the anterior spiracle eversion is often impaired and the mutant pupae show abnormal persistence of larval salivary glands in the pupal stage (beyond 30 hr after puparium formation). The mitochondria in late/pupae and prepupae do not undergo extensive fragmentation as is typical for wild-type and remain largely elongated.

Almost all embryos from mothers with germline consisting of solely Idh3b1 mutant cells (created by the ovoD technique) survive to segmented stages (although segmentation defects are frequent), some manage to hatch and a few survive to pupariation and adulthood.

At the onset of pupation, as staged by head eversion, Idh3b1/Df(3R)93Fx2 mutant midguts display the following phenotypes: 1. Mutants animals have a convoluted larval midgut epithelium. Larval midgut compaction is never observed as indicated by a large space in the larval lumen. Mutant larval midguts appear to be arrested at a stage of destruction that is similar to the midgut of wild-type pre-pupae 4-6 h following puparium formation. Mutant animals always form an adult epithelium, and the larval proventriculus and gastric caeca are destroyed. 2. DNA fragmentation is detected in all larval midgut cells of Idh3b1/Df(3R)93Fx2 animals at the onset of pupation, as staged by head eversion. 3. Mutant midguts possess numerous cells that contain swollen mitochondria, and many of these organelles rupture. Not all Eip93F mutant midgut cells completely lack autophagic structures, however, as some mitochondria are enclosed by membranes. Early stage autophagic vacuoles form in some cells. Between the white prepupa stage and head eversion, Idh3b1/Df(3R)93Fx2 mutant midguts decrease in length by an average of 74% in length compared to 85% in the wild-type.

Mutant salivary gland cells contain large eosin positive vacuoles and plasma membranes and show variable chromosome banding - phenotypes associated with delaying salivary gland programmed cell death due to a failure in the onset of autophagy.

Less than 12% of homozygotes die in the early stages of pupal development. These mutants fail to shorten their bodies properly at puparium formation, fail to tan, often exhibit a defect in anterior spiracle eversion and die following head eversion. Idh3b1/Df(3R)93Fx2, Idh3b2/Idh3b1 and Idh3b3/Idh3b1 flies have an identical phenotype. to homozygotes Unlike wild-type, Idh3b1/Df(3R)93Fx2 mutants possess persistent salivary glands, even though adult structures have formed, including eyes and wings.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressor of

Idh3b1/Df(3R)93Fx2 is a suppressor of increased cell death | heat sensitive phenotype of ftz-f1hs.PW

Phenotype Manifest In
Suppressor of

Idh3b1/Df(3R)93Fx2 is a suppressor | partially of salivary gland | heat sensitive phenotype of ftz-f1hs.PW

Additional Comments
Genetic Interactions

The addition of Idh3b1/Df(3R)93Fx2 to heat shocked ftz-f1hs.PW animals leads to a reduction in the cell death seen in salivary glands (and thus intact salivary glands) though DNA fragmentation is still seen.

Xenogenetic Interactions
Complementation and Rescue Data

The Eip93FΔ1 allele successfully complements Idh3b1 (from the former 'E93[1-3]' complementation group).

The lethality of Idh3b1/Df(3R)Exel6188 transheterozygous mutants is rescued by combination with a single copy of Idh3b+t3.0 as viable adults are recovered.

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Notes on Origin

The 'E93[1]' allele was previously assigned to the Eip93F locus, due to the chromosome containing a nonsense change near the 3' end of the Eip93F coding sequence (at codon 995 of the A isoform). However, the phenotypic effects of the 'E93[1]' chromosome appear not to be due to an effect on Eip93F, but are instead due to a mutation in the neighbouring Idh3b gene (mutation in a splice acceptor site), as 1: the mutant phenotype is rescued by a transgene carrying wild-type Idh3b and 2: the 'E93[1]' mutation fully complements Eip93FΔ1, a null allele of Eip93F. The lesion in Eip93F thus appears to be incidental and the 'E93[1]' allele has been renamed 'Idh3b[1]'.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (3)
References (12)