Ecdysteroid t i t e r s measured i n t h e haemolymph o f t h i r d i n s t a r l a r v a e o f Drosophila revealed t h e existence o f a small peak (40 ng/ml) preceding t h e major peak a t p u p a r i a t i o n . Under experimental c o n d i t i o n s o f delayed p u p a r i a t i o n , t h e release o f b o t h e c d y s t e r o i d peaks i s retarded. t h e programming o f t h e t i m e o f p u p a r i a t i o n i s r a i s e d . The p o s s i b i l i t y t h a t t h e e a r l i e r pulse i s i m p l i c a t e d i n I t i s known t h a t p u p a r i a t i o n i n t h e D i p t e r a i s induced by ecdysteroids (Fraenkel, '34; Butenandt and Karlson, '54). Several authors have measured e c d y s t e r o i d l e v e l s i n Drosophila melanogaster (Borst e t a l . , '74; De Reggie t a l . , '75; Hodgetts e t a l . , ' 7 7 ) . We are i n v e s t i g a t i n g t h e programming o f p u p a r i a t i o n i n t h i s animal and our s t u d i e s have l e d us t o examine w i t h g r e a t e r p r e c i s i o n m o l t i n g hormone t i t e r s throughout t h e t h i r d l a r v a l i n s t a r and e a r l y pupal period. whole animals.(Porcheron e t a l . , '76) we have been a b l e t o measure t h e e c d y s t e r o i d l e v e l d i r e c t l y i n small volumes of haemolymph. E a r l i e r measures were performed on homogenates o f

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Farnesylacetone is a natural terpene extracted from androgenic glands of the crustacean Curctnus maenas and is capable of inhibiting proliferation, notably in transformed mammalian cells. Flow cytometry with three lipophilic probes, diphenylhexatriene, trimethylammonium-diphenylhexatriene, and Nile red, has revealed modifications of the lipidic metabolism in transformed FR3T3-mTT4 rat fibroblasts treated by fatnesylacetone, including changes in membrane fluidity. Farnesylacetone strongly increased the number of neutral lipidic droplets in the cytoplasm. Moreover, after prolonged terpene treatment, the membrane hction of cells contained a substantial level of triglycerides. Famesylacetone provoked an immediate but transitory increase in membrane fluidity of the cell membrane. The change in measured lipid fluidity appears to be due to these triglycerides rather than to the phospholipids. o 1995 wiley-L~S, I~C .

2 C18 isoprenoid ketones, hexahydrofarnesylacetone (1) and farnesylacetone (2) have been identified for the first time in lipid extracts from the androgenic glands of the male crab Carcinus maenas, using coupled gas chromatography-mass spectrometry. The 2 compounds prepared by synthesis, are biologically active, inhibiting the incorporation of 3H-leucine in Crustaceans ovaries subcultures.