Analysis of nitric oxide-cyclic guanosine monophosphate signaling during metamorphosis of the nudibranch Phestilla sibogae Bergh (Gastropoda: Opisthobranchia).

The gas nitric oxide (NO), and in some cases its downstream second messenger, cyclic guanosine monophosphate (cGMP) function in different taxa to regulate the timing of life-history transitions. Increased taxonomic sampling is required to foster conclusions about the evolution and function of NO/cGMP signaling during life-history transitions. We report on the function and localization of NO and cGMP signaling during metamorphosis of the nudibranch Phestilla sibogae.

Evocation of venation pattern in the wing of a moth, Manduca sexta.

The insect wing is formed from an epithelial sheet that folds during development to establish a saclike tissue with an upper and a lower epithelial monolayer. The adult cuticle formed by the upper and lower monolayers has a distinctive pattern of thickened regions called veins. The venation pattern on the lower surface matches that on the upper surface.