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.
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.