84% of spin¹ stage 14 egg chambers show persisting nurse cell nuclei, compared to 7% in controls. 44% of spin¹/+ stage 14 egg chambers show persisting nurse cell nuclei.

67% of spin¹ germ line clone stage 14 egg chambers show persisting nurse cell nuclei.

Only 4% of mutant females that are paired with wild-type males copulate during an assay period of 1 hour (70% of wild-type females copulate with wild-type males under the same assay conditions). The time spent by the wild-type male performing unilateral wing vibration during a 10 minute observation (the SAPI - sex appeal parameter index) is almost identical for males paired with mutant or wild-type females, indicating that the low mating success of mutant females is not due to reduced attractiveness. Mutant females consistently display a number of rejection responses when paired with wild-type males, including fending, kicking, flicking, curling, punching and decamping, although extrusion is rarely seen. In response to approaching males, the mutant females tend to raise their abdomens while spreading their vaginal plates (this spreading behaviour is not seen in either wild-type virgin or fertilised females and is distinct from extrusion, in which the ovipositor protrudes from the female terminalia). The mutant females often rush towards the courting male, pushing the male's head with their forelegs (this aggressive "punching" behaviour is rare amongst wild-type females). spin¹/spin¹⁰⁴⁰³ females show a profound decrease in mating success compared to wild-type females when paired with wild-type males. The time spent by the wild-type male performing unilateral wing vibration during a 10 minute observation (the SAPI - sex appeal parameter index) is almost identical for males paired with spin¹/spin¹⁰⁴⁰³ or wild-type females. spin¹/spin¹⁰⁴⁰³ females show a number of rejection behaviours when paired with wild-type males, including fending, kicking, flicking, curling, punching and decamping, although extrusion is rarely seen. In addition, the mutant females show spreading behaviour (they raise their abdomens while spreading their vaginal plates), which is not seen in wild-type females. The mutant females show a high frequency of punching behaviour, which is rare amongst wild-type females. Mutant male flies show no obvious abnormality in their courtship behaviour. Homozygous females rarely lay eggs. Dorsal appendages are well formed in stage 14 egg chambers of mutant females, but the nurse cell nuclei are still present (in contrast to controls, where the nurse cell nuclei have degenerated by this stage) and some oocytes are degenerated. Mutant mature ovaries show an accumulation of hundreds of nurse cell nuclei near the basal stalk. General locomotor activity is reduced compared to wild type in mutant adults of both sexes. Mutants show a reduction in viability and in life span. Viability of females is 22% and viability of males is 11%, resulting in an uneven sex ratio of the emerged homozygous adults. The abdominal ganglion of homozygous adult flies of both sexes is longer than normal, while the thoracic segment of the ventral nerve cord appears normal. This unshortened morphology is still present 2 weeks after eclosion. Homozygous animals show autofluorescence in the ventral nerve cord (mainly in the central region), particularly in the abdominal ganglion of pupae and adults, due to the cells containing autofluorescent lipopigments with characteristics similar to those of lipofuscin. Ultrastructural analysis indicates that most cells in the mutant abdominal ganglion contain aberrant structures - multilamellate bodies and electron-dense lobulated granules - that are never seen in control animals. These defects are seen in the central nervous system from the early pupal stage onwards and are seen in both sexes.

Low mating success, females exhibit strong mate-refusal. Receptivity reaches maximum on day 2 (12.5% of wild type levels) and declines rapidly thereafter.

Low mating success: virgin females perform repeated repelling movements that cause abortive mating.