In drd^lwf homozygous females and hemizygous males the midgut and cardia are severely distended and lack a peritrophic membrane. Alongside, the presence of holes in the brain indicate signs of neurodegeneration.

Approximately 50% of mutant adults have larger crops than wild-type controls.

After 22-24 hours on dyed food, the mutant adults have less dye in their midguts than wild-type controls.

Nearly 50% of mutant flies do not eat after 48 hours of starvation. For flies that do eat, there is no significant transfer of food to the midgut over the 90-minute duration of the experiment (in contrast, wild-type flies show a steady increase in midgut staining starting 15 minutes after the beginning of feeding with dyed food under these conditions). The mutant flies show a gradual increase in crop volume over the 90 minutes, in contrast to wild-type flies which show a decrease in crop volume.

Mutant and wild-type flies starved on agar have a median survival of 3 days, with no significant difference between the survival curves of both genotypes. Mutant flies kept on instant food or cornmeal-molasses food show show an increase in survival compared to mutant flies starved on agar, but show reduced survival compared to control flies kept on instant food or cornmeal-molasses food.

Mutant males and females show a significantly higher rate of spontaneous crop contraction compared to controls.

drd^lwf flies are short-lived and display abnormal digestive function. Mutant flies frequently have a 'bloated' appearance; this is due to the accumulation of large amounts of liquid in the crop. drd^lwf males have more than a four-fold increase in crop volume compared with wild-type males. Homozygous females have a nearly three-fold increase compared with heterozygotes.

drd^lwf mutant flies display a significantly reduced rate of defecation. No accumulation of food is observed in any portions of the gut other than the crop.

The lethality observed in drd^lwf flies appears to be confined to adult flies. No gross abnormalities are observed in either the survival of mutants through pre-adult development or the timing of such development.

drd^lwf mutants are smaller than wild-type flies. The mean mass on the day of eclosion of drd^lwf males and homozygous females is 25-30% smaller than wild-type males and heterozygous females, respectively.

drd^lwf females are sterile. They lay very few eggs and no larvae appear from crosses with drd^lwf homozygous females. Homozygous drd^lwf ovaries contain significantly fewer egg chambers that have undergone vitellogenesis compared with heterozygotes. Indeed, mutant flies, on average, have less than one yolk-containing egg chamber in each ovary.

Starvation of drd^lwf heterozygous females results in a significant disruption of oogenesis.

drd^lwf/drd¹ transheterozygous females are short-lived, sterile, have a smaller body mass, and fewer vitellogenic egg chambers than drd¹/+ heterozygotes.

drd^lwf/drd^CB6275-3 transheterozygotes exhibit an increase in crop volume compared to wild-type.

drd^lwf/drd¹ transheterozygotes exhibit an increase in crop volume compared to wild-type.

drd^lwf/drd^CB6275-3 transheterozygotes exhibit a smaller number of vitellogenic egg chambers compared to wild-type.

drd^CB6275-3/drd^lwf females do not have a lower body mass than there siblings and are fertile.

Mutant flies begin dying 2-3 days post-eclosion and show 100% lethality within 7 days. By the time they die, lwf¹ flies exhibit distended crops, suggesting that they are able to eat. However, little food appears to move into and through the midgut and hindgut, as lwf¹ males show an 80% reduction in the production of fecal spots compared to wild-type flies, during the second and third days of adult life.

lwf¹/lwf^CB6275-3 flies display 80% mortality within 7 days post-eclosion.