Fig. 2. Homozygous rk4 flies show delayed
post-ecdysial tanning. Photomicrographs show the dorsal abdominal cuticle
dissected from (A) wild-type males or (B) females and (C)
rk4homozygous males or (D) females at 3 h after
eclosion. Cuticles are mounted to show the extent of melanization.