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.