loqsf00791 mutant flies have a significantly shortened lifespan and show late-onset brain morphological deterioration. The brains of young adults appear normal, but by 25 days the flies have developed large vacuoles in the retina and lamina of the brain.
loqsf00791 mutants display a reduction in dsRNA processing and a subsequent ~60% reduction in siRNA levels.
The longitudinal and commissural axon structures of the central nervous system are disrupted in homozygous embryos.
Approximately 70% of homozygotes die before adulthood, and surviving males have reduced fertility and surviving females are sterile. Surviving adults are often stuck in the food.
Homozygous adults have significantly reduced locomotor activity compared to controls.
loqsf00791/loqsKO females have an average of 0.5 germline stem cells (GSCs) per germarium at 10 days after eclosion, compared to an average of 2-3 GSCs per germarium in wild-type females at this age. Differentiated cystoblasts with posterior-positioned fusomes are often seen at the normal location of GSCs in the germaria of loqsf00791/loqsKO females.
loqsf00791 mutants exhibit minimal disruption to the eye.
Only 17% of embryos derived from homozygous males mated to wild-type females hatch. Mutant males contain crystals of Ste protein in their testes. Mutant females have small ovaries and are completely sterile, failing to lay any eggs. The mutant ovarioles contain a smaller than normal germarium and contain only 2 or 3 previtellogenic egg chambers and a late-stage egg chamber (in contrast to the developmentally ordered array of 6-8 egg chambers seen in wild-type ovarioles). The mutant germarium contains only a few germ-line cells, which are not organised into distinct cysts. Spectrosomes can not be detected in the mutant germaria of 3-4 day old females, suggesting that no stem cells remain in these flies. The follicle cell layer is significantly reduced compared to wild-type. Mature oocytes in the mutant ovarioles have normal dorsal appendages.
loqsf00791 mutant females are completely sterile while males are approximately 60-70% sterile when compared with the control crosses between heterozygous and wild-type flies. Although mutant testes appear normal, mutant ovaries contain a few maturing egg chambers and a shriveled germarium with few healthy germline stem cells. The mutant ovary does not sustain continuous egg chamber production since germline stem cells can not be properly maintained.