Abstract
Corpus allatum (CA), a pair of the endocrine glands, synthesize and release juvenile hormone (JH) to regulate the development and reproduction of insects. In the larval stages of Drosophila, CA and prothoracic gland (PG) are located in a structure called ring gland. Previous report indicates that some neurosecretory cells near the mushroom bodies extent their axonal processes into CA of the ring gland. However, the developmental changes of CA and the upstream regulator of those CA-innervated neurons are still unclear. In this thesis, I used confocal analysis in combination with immunol ling, counterstaining techniques to monitor the developmental changes of CA. For examine the regulatory sequencing between mushroom bodies and the CA-innervated neurosecretory cells, some neurosecretory Gal-4 lines were selected to identify the distributions of the l led neurons. Besides, the chemical ablation by hydroxyurea (HU) treatment, which partially ablated mushroom bodies, was applied to observe the upstream influence on neurosecretory cells. The results showed that the cell numbers of CA reached to the peak at the third instars and dramatically declined before the entrance of puparation. However, the volume of CA gradually increased during development. These results in comparison with the published data of JH biosynthesis in Drosophila suggested that the changes of cell numbers and the cell sizes might respond for JH biosynthesis and storage, respectively. Furthermore, I found that the HU treatment resulted in the damages of mushroom bodies, the decrease of the l led somata and the difference of the GFP expression patterns. Although, the real mechanism was not elucidated, three possibilities might be concerned: the direct cell killing effect, the differentiation interference, and the abolishment of the upstream signaling. Thereafter, under the controlled damage on mushroom bodies, the developmental observation of neurosecretory cells and CA will provide information for understanding the regulatory relationship between mushroom bodies and neurosecretory.