Gfrl^del larvae are frequently immobile or sluggish in response to touch and show a range of feeding defects, as compared to controls: a foraging phenotype in which larvae move away from a central food source; accumulation of food in the oesophagus; reduced/absence of food in the midguts and absence of food in the oesophagus. Embryos show asymmetry of the frontal ganglion and disruption to the esophageal ganglia.

Gfrl^del/Df(3R)Exel6185 females mated to wild-type males show a reduction of approximately 60% in absolute fertility and a reduction of approximately in fecundity (measured as number of progeny per female at 72 hours post-mating).

Gfrl^del/+ females mated to wild-type females have fertility comparable to that of wild-type females.

Homozygous and Gfrl^del/Df(3R)Exel6185 females lay very few eggs. Most of the eggs laid are small (showing a significant reduction in length compared to wild type) and translucent, and have dorsal appendage defects and do not develop into larvae.

Homozygous and Gfrl^del/Df(3R)Exel6185 males show significantly reduced fertility and homozygous males show significantly reduced fecundity compared to wild type.

Gfrl^del/Df(3R)Exel6185 has male semi-sterile phenotype, enhanceable by Fas2^e76

Gfrl^del has male semi-sterile | recessive phenotype, enhanceable by Fas2^e76

Fas2^e76, Gfrl^del has male sterile phenotype

Gfrl^del/Df(3R)Exel6185, Fas2^e76 has male sterile phenotype

Gfrl^del/Df(3R)BSC518, Fas2^e76 has male sterile phenotype