The fertility of homozygous females and hemizygous males is severely reduced, although a few adult progeny can be obtained from mutant parents. Hemizygous adult males weigh on average only 93% of the weight of control males. The average wing area of hemizygous males is only 93% that of wild type and the number of cells in the wing is 92% that of wild type. The cells in the wing of hemizygous males are slightly increased compared to wild type. Homozygous clones in the wing induced approximately 60 hours after egg laying and allowed to develop for a further 60 hours cover only about 60% of the area of the control sister clones. There is no increase in the number of apoptotic cells associated with the mutant clones, and the mutant cells show no significant differences in cell size or cell-cycle phasing compared to control cells. Endoreduplication is not initiated on time in the central domain of the midgut in mutant embryos, and is inefficient and not completed on time within the anterior and posterior midgut domains.