STUDY OF CYCLIC-NUCLEOTIDE PHOSPHODIESTER ASE ACTIVITY IN MUTANT DROSOPHILA-MELANOGASTER STRAINS

The activities of general phosphodiesterase and its Ca2+-calmodulin-de pendent form (PDE-1) were studied in strains mutant for the agnostic g ene and in the strain Canton S. Enzyme activity was determined in male s and homo- and hemizygous females of four strains, It was found that mutation at the agnostic gene resulted in increased PDE-I activity. Th is effect appears to depend on the dose of the mutant gene, because it was revealed only in homozygous females. We have substantiated the no tion that the agnostic gene controls calmodulin properties by virtue o f encoding a calmodulin-inhibiting protein.