Pathway and regulation of JHIII‐bisepoxide biosynthesis in adult Drosophila melanogaster corpus allatum

Abstract

Adult female Drosophila melanogaster corpus allatum (CA) synthesize JHB₃ from endogenous and exogenous precursors in vitro. We present evidence supporting the thesis that biosynthesis proceeds from precursor FA via initial epoxidation and terminal methylation on the basis of the following: (1) Methyl farnesoate is not epoxidized to JHIII or JHB₃; (2) Authentic JHIII is not epoxidized to JHB₃; and (3) FABE is markedly metabolized to JHB₃. Cerebral allatostatic factors act at some stage subsequent to FA and this precursor is not normally rate‐limiting. Additionally, neural inhibition from the brain acts at some biosynthetic step prior to FA.