碩士 / 國立中山大學 / 海洋科學系研究所 / 103 / Water depth and the amount of suspended particles shape the light spectrum of an aquatic environment. In clean open water, the full spectrum is attenuated to blue right as the depth increases. However, shortwave blue light is absorbed by suspended particles in turbid water, leaving a red light dominant photic environment. Gobiidae are distributed widely in various habitats with varying photic environments, making them good candidates to study the relationship of habitat divergence and fish opsin evolution. Three goby species, freshwater bumblebee goby (Brachygobius doriae), brackish mudskipper (Periophthalmus modestus) and ocean silver-spotted goby (Exyrias puntang), inhabiting different photic environments were used to study the relationship between opsin gene evolution and habitat divergences. Two types of SWS2 genes, SWS2A and 2B, were identified in these gobies, and an amino acid substitution L116T, were found between them. Three types of LWS genes were observed in this study, LWSA1/A2 and LWSB. Two substitutions, A164S and F261Y, were found among LWS genes. These substitutions make mudskippers and bumblebee gobies better ability to detect blue or blue/red light, respectively. We also found gene duplication events occurred twice in LWS, and LWSA/B gene duplicated before common ancestor of teleost appeared. Futhermore, only gobies in this study possess LWSB gene while other teleost loss it and this is inferring that detecting red light might quite nececery for gobiidae. All these differences appeared among evolution and generating a diverse set of opsin gene of gobies living in different habitats. This result suggest opsin genes of species in this study were distinct because of affect from photic environments.
| Identifer | oai:union.ndltd.org:TW/103NSYS5276015 |
| Date | January 2015 |
| Creators | Tzu-wei Liu, 劉子維 |
| Contributors | Feng-Yu Wang, Houng-Yung Chen., 王豐寓, 陳宏遠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 75 |
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