heph2 heterozygous third instar larval mitotic neuroblasts exhibit an abnormal number of chromosomes compared to controls.
At 25[o]C, only 8% of heph2 flies reach adulthood. The survival frequency is increased to 33% and 67% when mutant flies are raised at 21[o]C and 17[o]C respectively.
The testis tips of heph2 mutants are swollen to many times their normal diameter. The testes show a lack of motile sperm, and a pronounced accumulation of cysts of elongated spermatids. A few cysts of elongated spermatids appear to be partially individualized, and spermatids in cysts often have numerous bulges along their length which is not observed in wild-type testes.
Despite severe defects in spermatid individualisation capase activity is detectable in spermatid cysts of heph2 homozygotes, as in wild-type at this stage.
The tip of the testis in homozygotes is enlarged and males are sterile. Mutant testes accumulate cysts of elongated spermatids, and the enlarged tip is also filled with these cysts. In addition mutant lack fully individualised motile sperm. All of the stages up to elongated sperm can be seen. The majority of the elongated spermatid show numerous bulges along the tails characteristic of a defect during the individualisation process.
Tip of testis is dilated to twice wild type circumference.
Tip of testis dilated to approximately twice the wild type circumference.