Divergence of the Regulation of alpha-Amylase Activity in Drosophila melanogaster, Drosophila funebris, and Drosophila saltans

The regulation of amylase activity in threeDrosophila species, D. melanogaster,D. funebris and D. saltans, wasanalyzed by measuring the specific activity levels infour dietary environments, cornmeal, glucose, 5% starch, and 10% starch, at threedevelopmental stages, i.e., the third-instar larval,pupal, and 2-day-old adult stages. The developmentalprofiles of amylase activity for the threeDrosophila species showed that the level of activity washigh at the larval and adult stages but substantiallylow at the pupal stage, suggesting thatDrosophila does not utilize starch at the pupalstage. Divergence in the regulation of amylase was observed amongthe three Drosophila species on the followingpoints. (1) The order of amylase specific activity wasD. melanogaster > D. funebris >D. saltans. (2) The response pattern to the dietary environment varied amongthe species and changed during development. (3) Thetiming of the switch in the response pattern to thedietary environment during development was before pupation in D. funebris and D.saltans but after pupation in D.melanogaster. The significance of the divergence inthe regulation of amylase activity for adaptation to astarch environment in Drosophila is discussed.