A developmental study of acid phosphatase-1 in Drosophila melanogaster.

The developmental profile of acid phosphatase-1 activity in Drosophila melanogaster indicates that this lysosomal gene-enzyme system (Acph-1, 3–101.1) is responsible for ca. 90% of the low-pH nucleotidase activity throughout development. The enzyme is present at particularly high levels during embryogenesis. It is shown with electrophoretic variants and null mutants of acid phosphatase-1 that virtually all of the embryonic enzyme is maternal in origin and is made during oogenesis. The enzyme exists in several isozymic forms at fertilization, and all but one of these forms disappear during early embryogenesis. Detectable maternal enzyme persists until the third larval instar stage. Crosses between females homozygous for a null allele and wild-type males show the zygotic Acph-1 gene activation occurs by at least 9 hr after oviposition.