P{FZ} insertion in the first intron.
P{lacZ} enhancer trap element inserted in 1st intron.
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.
Of 20 P element-induced excisions of the P element in cact255, 8 had completely restored cactus function.