碩士 / 國立高雄海洋科技大學 / 海洋生物技術研究所 / 101 / The photosynthetic endosymbiosis between corals and their dinoflagellate symbionts is the primary cause for the establishment and prosperity of coral reefs ecosystem in the nutrient-poor tropical oceans. Despite this fundamental importance, its underlying cellular and molecular mechanism remains largely unknown. Since dinoflagellates exclusively reside in the host vacuole, called the symbiosome, during their symbiotic life, we investigated the involvement of ApRab22, a member of the Rab small GTPase family, key regulators of vesicular trafficking, using the tropical sea anemone, Aiptasia pulchella as a model. A. pulchella homologue of Rab22 proteins, ApRab22 , a protein of 215 amino acids, is 72 % identical to human Rab22 protein and contains all Rab-specific signature motifs. Results of EGFP reporter analysis indicated that EGFP-ApRab22 fusion protein is mainly located in one side of the nucleus, and also present in punctate and reticular structures throughout the cytoplasm judged by the distribution of EGFP fluorescent signals. Depolymerization of microtubules by nocodazole treatment resulted in the disappearance of reticular fluorescence signals, suggesting transport of ApRab22-associated vesicles along the cytoskeleton. Endocytosis and phagocytosis analyses indicated that, ApRab22 is located in the early endosomes, early phagosomes, and recycling endosomes. In addition, immunefluorescence assay found that ApRab5 and ApRab22 are co-localized on the symbiosome. Significantly, when the alga was treated with the photosynthetic inhibitor, DCMU, symbiosome association of ApRab22 was largely abolished. I therefore, propose that ApRab22 is an important regulator for the establishment and maintenance of the photosynthetic endosymbiosis between A. pulchella and its algal symbionts.
| Identifer | oai:union.ndltd.org:TW/101NKIM0270007 |
| Date | January 2013 |
| Creators | Shin-Yu Wu, 吳昕燏 |
| Contributors | Ming-Chyuan Chen, 陳鳴泉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 100 |
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