Changes in Lipid Biosynthesis During Development of the House Cricket, Acheta domesticus (Orthoptera: Gryllidae)

Abstract

The incorporation of [I-14·e] acetate into lipid was monitored during the final three stadia of male and female house crickets, Acheta domesticus (L.). Large fluctuations in lipid bio-synthesis –total lipid synthesis and the synthesis of various classes of lipid were observed for males and females during development. All three stadia showed low levels of radiolabel incorporation near ecdysis. Peak incorporation occurred at midstadium. All lipid classes examined (triacylglycerol [TG], phospholipid [PL], hydrocarbon [HC], diacylglycerol, alcohol, and free fatty acid) showed similar patterns. No differences in lipid biosynthesis were observed between male and female nymphs. However, adult females showed a distinct peak of [1·14. C] acetate incorporation into total lipid and into the TG fraction 2–3 d after ecdysis. This peak corresponded to the initiation of vitellogenesis. Males showed a more gradual increase in lipid biosynthesis through day 7. Near ecdysis, the relative distribution of radioactivity showed that the radio labeled acetate was incorporated into HC and PL in a higher proportion than it was into TG. By day 2, about 70% of the lipid synthesized was incorporated into TG by males and females. In general, the large changes in lipid synthesis correlate closely with the physiological needs of the insect associated with its development.