| The mechanism of hydrocarbon biosynthesis was examined in the flesh fly, Sarcophaga crassipalpis, the blow fly, Phormia regina, the German cockroach, Blattella germanica, the house cricket, Acheta domesticus, the mormon cricket, Anabrus simplex, the damp wood termite, Zootermopsis nevadensis, and in the housefly, Musca domestica. Microsomal preparations from each species readily converted [9,10-3H2]octadecanal (18:0 Ald) to heptadecane. NADPH and O2 were required for enzymatic activity in all cases, and very little hydrocarbon was formed under anaerobic conditions. Radio-GLC analyses of the head space gas formed from the metabolism of [1-14C]18:0 Ald by microsomes from M. domestica, S. crassipalpis, P. regina and B. germanica clearly showed that 14CO2 and not 14CO was formed. Quantitation of the products from the metabolism of [1-14C] and [9,10-3H2]18:0 Ald in microsomes from M. domestica, P. regina, S. crassipalpis, B. germanica and Z. nevadensis showed that an approximate 1/1 ratio of 14CO 2/[3H2]17:0 Hyd was formed. The data support a mechanism in which the aldehyde is converted to hydrocarbon and CO 2 in insects.;The epicuticular and internal waxes of both sexes of the housefly, M. domestica, were examined by capillary gas chromatography-mass spectrometry at closely timed intervals. Newly identified components included tricosan-10-one, 9,10-epoxyheptacosene, heptacosen-10-one, a series of odd-carbon numbered dienes from C31 to C39, several positional isomers of monoenes including (Z)-9-and 7-pentacosene and a number of methyl- and dimethylalkanes. (Z)-9-Tricosene appears in the internal lipids first, then on the surface of the insect, suggesting that it is transported in the hemolymph to the exterior. The C23 epoxide and ketone only appear in females after the production of (Z)-9-tricosene is induced and are only abundant in the epicuticular waxes, suggesting they are formed after (Z)-9-tricosene is transported to the cells involved in taking them to the surface of the insect. The time shift between internal production and external accumulation in females is more than 24 hours. The divergence between male and female lipid production occurs at an early stage, when insects are less than one day old. |
