cact1/cact4 larvae do not show R2-R5 photoreceptor axon targeting defects in the developing visual system.
Mutant third instar larvae have melanotic nodules found in the hemocoel or in association with He-positive lymph glands. They also show gut melanisation not accompanied by tissue overgrowth or hemocyte encapsulation.
cact1/cact4 mutant embryos exhibit a strong ventralised phenotype.
Pupal lethal when heterozygous with the MBT chromosome.
Weakly ventralised embryos. When maternal or zygotic tkv levels are reduced most of the embryos die and show an increased level of ventralisation.
Strong ventralizing phenotype: lack of all dorsally and laterally derived structures and the expansion of the ventral epidermis around the entire circumference. Expansion of twi expression in terminal regions.
Embryos from homozygous mothers appear 'ventralized'; at differentiation they form only a narrow strip of dorsal cuticle, whereas ventral setal belts are expanded and encircle in irregular fashion most of the embryonic periphery. At gastrulation the germband hardly extends at all and the posterior midgut invaginates close to the posterior pole. Cephalic furrow is more pronounced than in wildtype.