Interaction in vitro; protein derived from adult fly extract.

Three bands are visible in the zymogram of heterozygotes: a slow band (seen in "slow" homozygotes), a fast band (seen in "fast" homozygotes) and an intermediate band. This is consistent with the formation of a heterodimer consisting of the Acph-1 "slow" and "fast" variants, and suggests that Acph-1 exists as a homodimer or higher order multimer.

Protein extracts from heterozygous flies carrying alleles encoding both the "slow" and "fast" forms of Acph-1 were run out on a gel, and in-gel enzymatic phosphatase activity was assayed (zymogram). These were compared to extracts from homozygous flies carrying just the "slow" or "fast" alleles.