Esterase 6 of Drosophila melanogaster: Kinetics of transfer to females,decay in females and male recovery

Esterase 6 (E.C. 3.1.1.1) is an enzyme in the reproductive system of Drosophila melanogaster and is transferred from males to females at mating. This enzyme is conveyed during the first 3 min of a copulation lasting approximately 20 min and remains active in the female reproductive tract for 1–2 hr after mating. Males require 24–48 hr to recover premating levels of esterase 6 activity. These results suggest that the effect of esterase 6 on the rate of sperm loss in females, which extends to 4 days after mating, is indirect since activity in the female falls rapidly after insemination. It is suggested that esterase 6 may also be a part of a pheromone system which influences female reproductive behaviour.