Shiga Sakiko, Hamanaka Yoshitaka, Tatsu Yoshiro, Okuda Takashi, Numata Hideharu
Department of Bio- and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan.
Zoolog Sci. 2003 Oct;20(10):1199-206. doi: 10.2108/zsj.20.1199.
In vitro synthetic activities of juvenile hormones (JH) were examined using a radiochemical assay in diapause females and reproductive females of the blow fly, Protophormia terraenovae. Thin layer chromatography showed that products of the corpus allatum (CA) comigrated with a synthetic sample of JH III bisepoxide but neither with JH III nor methylfarnesoate. JH synthetic activities increased in females reared under LD 18:6 at 25 degrees C, as the ovaries developed. The synthetic activities remained low in previtellogenic females reared under LD 12:12 at 20 degrees C. Removal of the pars intercerebralis completely prevented ovaries from development under reproductive conditions, and removal of the pars lateralis caused partial or full development of ovaries under diapause-inducing conditions. In these operated animals, the JH synthetic activities were not significantly different from those of the intact and sham-operated animals. The results indicate that the CA in P. terraenovae produces mainly JH III bisepoxide and a decrease in the JH production rate is a cause of diapause induction. PI neurons and PL neurons in the brain do not directly mediate changes in the JH production rate, but regulate ovarian development cooperatively with some unknown allatostatic and allatotropic factors.
利用放射化学分析法，对新陆原伏蝇滞育雌蝇和生殖雌蝇的保幼激素（JH）体外合成活性进行了检测。薄层色谱分析表明，咽侧体（CA）的产物与JH III双环氧物的合成样品迁移率相同，但与JH III和法尼酸甲酯均不同。随着卵巢发育，在25℃、光照周期为18:6条件下饲养的雌蝇，其JH合成活性增强。在20℃、光照周期为12:12条件下饲养的卵黄发生前期雌蝇，其合成活性较低。去除脑间部可完全阻止生殖条件下卵巢的发育，而去除侧部则会导致滞育诱导条件下卵巢部分或完全发育。在这些手术处理的动物中，JH合成活性与完整和假手术动物相比无显著差异。结果表明，新陆原伏蝇的CA主要产生JH III双环氧物，JH产生率的降低是滞育诱导的原因。脑中的PI神经元和PL神经元并不直接介导JH产生率的变化，而是与一些未知的咽侧体抑制因子和咽侧体刺激因子协同调节卵巢发育。
