PATHWAY AND REGULATION OF JHIII-BISEPOXIDE BIOSYNTHESIS IN ADULT DROSOPHILA-MELANOGASTER CORPUS ALLATUM

Adult female Drosophila melanogaster corpus allatum (CA) synthesize JH B(3) from endogenous and exogenous precursors in vitro. We present evi dence supporting the thesis that biosynthesis proceeds from precursor FA via initial epoxidation and terminal methylation on the basis of th e following: (1) Methyl farnesoate is not epoxidized to JHIII or JHB(3 ); (2) Authentic JHIII is not epoxidized to JHB(3); and (3) FABE is ma rkedly metabolized to JHB(3). Cerebral allatostatic factors act at som e stage subsequent to FA and this precursor is not normally rate-limit ing. Additionally, neural inhibition from the brain acts at some biosy nthetic step prior to FA. (C) 1995 Wiley-Liss, Inc.