Alkaline phosphatase in Drosophila melanogaster strains differing in male mating activity and their F-1 hybrids

The activity of alkaline phosphatase (AP) was studied in adults of highly a ctive (HA) and low active (LA) Drosophila melanogaster strains and their F- 1 hybrids, both under normal conditions and after a heat shock (38 degrees C). Under normal conditions, the HA strain expressed a higher AP activity c ompared to that in the wildtype strain Canton-S and dominated in respect to this character. The AP activity showed a sexual dimorphism, as it was high er in females of both strains. Heat shock (38 degrees C) induced no alterat ions in the AP activity of D. melanogaster.