HORMONES REGULATING STRUCTURAL-CHANGES IN THE ADIPOCYTES OF THE FEMALE EARWIG LABIDURA-RIPARIA

Changes in periovarian fat body fine structure occur during the reprod uctive cycle of the female earwig Labidura riparia. During the process of vitellogenesis, high levels of protein synthesis are seen in the a dipocytes. Simultaneously, the formerly osmiophilic lipid droplets bec ome non-osmiophilic, while an osmiophilic material diffuses from lipid droplets to the cisternae of the rough endoplasmic reticulum (RER). T hese structural features alter during non-vitellogenic periods:RER and Golgi apparatus regress and seem to be inactive. Lipid droplets are o nce again osmiophilic and no material enters into RER cisternae. Using microsurgical manipulations, hormonal treatments and light and electr on microscopy, we have investigated the regulation of these changes. T he neuroendocrine cerebral centre pars intercerebralis, by the action of the juvenile hormone of the corpus allatum, triggers protein metabo lism. Another neuroendocrine center, the pars lateralis, and the hormo ne 20-hydroxyecdysone, regulate structural lipid droplet changes in th e adipocytes.