Imaginal discs of homozygous larvae are missing or degenerate. Defects in the cell cycle: few or no dividing cells, affects chromosome condensation, arrest of the cell cycle at metaphase and cell division failures that result in highly polyploid cells.

Mutant larvae tend to be smaller than usual, and show signs of degeneration to varying degrees in most tissues, this degeneration increasing with age. Hemizygous second instar larvae have small, degenerate and disorganised imaginal discs, which progressively worsen with age. Third instar larvae have smaller than normal brains and as the larvae age, vacuolated areas are observed in the brain lobes. There is no organised optic lobe complex, and the imaginal ring of the foregut is absent. The salivary glands and male gonads are reduced in size, and hemopoietic cells normally associated with the dorsal vessel are almost completely absent.

Discs missing or degenerate; mitotic index of larval ganglion cells three times that of controls; chromosomes highly condensed as seen in colchicine-treated cells; 20% of metaphases polyploid; chromosome fragmentation common; no anaphase figures seen (Gatti and Baker, 1989). Homozygous cells in ovary lethal (Perrimon, Engstrom and Mahowald, 1984). pupal lethal mitotic phenotype: hypercontracted chromosomes, no anaphase, polyploid cells