Distribution of a Methionine Enkephalin-Like Substance in Gonads of Drosophila melanogaster

Summary

By means of the peroxidase-antiperoxidase (PAP) technique, methionine enkephalin immunoreactivity was demonstrated in ovaries and testes of Drosophila melanogaster. In all ovaries the germarium is immunopositive. Immunopositivity appears in the follicle cells from stage 6 and 7 and in the ooplasm from stage 7. Increasing immunoreaction was visualised in nurse cells of all successive stages. From stages 11 and 12 on, immunoreactivity is absent. Apart from the mature spermatozoa, all cells of the spermatogenic line are immunopositive. No immunoreactivity is found with antisera against leucine enkephalin and β-endorphin. Possible functions of the methionine enkephalin-like material are discussed.