Fully rescues the l(2)gl⁴ phenotype when raised at the permissive temperature of 22^oC. However, drastic effects on the development of these flies are seen at the restrictive temperature of 29^oC, in particular the fertility of females is strongly reduced. The fertility of males is not affected. Newly hatched females raised at 22^oC and then immediately shifted to 29^oC are unable to produce eggs. Females maintained at 22^oC for 2-3 days after eclosion and then shifted to 29^oC show a nearly normal rate of egg laying during the first day at 29^oC, with the rate of egg laying gradually decreasing to about 5% of the control rate after 3 days at 29^oC. Eggs laid by females at 29^oC have normal morphology and can be fertilised, although their development is blocked when the eggs are maintained at this temperature. Eggs laid for 2 hours by females maintained at 29^oC and then incubated at 22^oC show normal development. The morphology of ovaries of females carrying l(2)gl^F311 in a l(2)gl⁴ background and reared at 22^oC is indistinguishable from wild type. Ovaries of females carrying l(2)gl^F311 in a l(2)gl⁴ background, shifted to 29^oC immediately after hatching and reared at 29^oC for 2 days are severely reduced in size, due to a lack of late stage egg chambers. Ovaries of 5 day old females carrying l(2)gl^F311 in a l(2)gl⁴ background, shifted to 29^oC immediately after hatching and reared at 29^oC for 3 days show a marked depletion of egg chambers beyond stage 9. A few ovarioles which have a nearly mature egg are seen, but in these cases the egg is found to follow a degenerating egg chamber. In all other ovarioles the most developed egg chambers show degenerating characteristics (a reduction in size, abnormally arranged nurse cells and a disorganised cytoskeleton) while early stage egg chambers appear normal. The most advanced egg chambers reach stage 9 with a large proportion of the follicle cells being located over the oocyte. The stage 9 egg chamber is smaller than wild type. The layer of follicle cells over the oocyte form an antero-posteior gradient of increasingly elongated cells with an irregular shape and irregularly spaced nuclei. No sharp transition between columnar cells and squamous cells can be detected. The columnar follicle cells over the posterior end of the egg chamber can become extremely elongated. The border follicle cells reach their final destination, as seen by their lateral alignment, however they remain located within the layer of nurse cells bordering the oocyte and are never seen apposed to the anterior border of the oocyte. The nuclei of the most distally located egg chambers in more than half of the ovarioles are very condensed and fragmented, and the cytoskeleton of the nurse cells and oocyte is disrupted in the most advanced degenerating egg chambers. Apoptotic cell death is seen in the degenerating egg chambers.