Deletion of 70 amino acids (381-450), removing the H3 heptad repeat.
Mutant ovaries consist of mostly wild-type egg chambers. Abnormal numbers of germ cells can be seen. In BicDH mutants the differentiation of the follicle cells is not affected, but the migration of the cells can be abnormal. During stage 2b Fas3 expressing follicle cells migrate between the interconnected cystocytes of the germline cysts, rather than migrating only on the surface of the cysts. Second, gaps in the follicle cell layer are occasionally detected in region 3 of the germarium. In BicDH mutants bipolar egg chambers are sometimes seen. Defects in the nuclear morphology of oocyte nuclei are seen, Occasionally polyploidy and intermediate polyploidy is seen in the oocyte nucleus of these egg chambers. The formation of the microtubule organising centre (MTOC) seen in germarial region 2a is normal.
~1% of eggs laid by BicDH3, BicDr5/Df(2L)TW119 females display a mildly ventralised dorsal appendage phenotype.
Rescues zygotic viability of BicDr5/Df(2L)TW119 at rates ranging from 85% to 95%. Almost completely rescues the female sterility defect of BicDr5/Df(2L)TW119.