emcΔ1/emcAP6 mutants rescued by the expression of emcUAS.cdCa under the control of Scer\GAL4Act.PU survive to pharate adults, and a small proportion emerge as adults; both adults and pharate adults exhibit almost normal eye development, including the interommatidial bristles, an essentially normal pattern of thoracic macrochaetae, despite the lack of most microchaetae, a spaced pattern of some microchaetae, and a reduced by essentially normal pattern of wing margin bristles, as compared to controls.
Homozygous mutant emcAP6 cells survive in the larval and pupal stages if the mutant clones are induced in a background heterozygous for a minute mutation (RpS17unspecified). It is possible to obtain eye imaginal discs almost entirely comprised of emcAP6 mutant cells, when clones are generated using Scer\FLP1ey.PN induced recombination in a trans-heterozygous emcAP6-RpS17unspecified background.
emcAP6 mutant eye discs have an overall narrower shape. Morphogenetic furrow progression is accelerated in the ventral half compared to that of dorsal half. Patterning of the developing eye field is severely affected. The number of photoreceptor neurons per ommatidium is irregular as is the arrangement of photoreceptor neurons within ommatidial clusters. Occasionally, ectopic differentiating neurons are seen ahead of the morphogenetic furrow. The number of cone cells is significantly reduced. The apical nuclear migration typical of cone cells is delayed or absent in ommatidia. R7 photoreceptor cells are almost completely lost in eye imaginal discs almost entirely comprised of emcAP6 mutant cells. However, in smaller emcAP6 mutant clones, the presumptive R7 photoreceptor cells maintain their neuronal identity, but they fail to differentiate appropriately and maintain the R7 receptor fate. This effect is cell autonomous. emcAP6 mutant cells in the R7 position display R1/6-like properties in the form of ectopic svp expression. In emcAP6 mutant eye discs, ommatidia rotate normally in the dorsal half, whereas almost all ventral ommatidia rotate abnormally in the same direction as in the dorsal half. R4 photoreceptor specification is also affected in emcAP6 mutants.
The density of cells in homozygous follicle cell clones is higher than their wild-type neighbours.
Embryos exhibit defects of the Malpighian tubules and midgut.