碩士 / 東海大學 / 生物學系 / 92 / Crabs widely distribute through aquatic to terrestrial habitats. They are excellent experimental species to study the morphological changes and physiological adaptation during their terrestrial invasion. Decapod crabs are species of marine ancestor. The hemolymph osmoregulation in brackish water is crucial for a successful terrestrial invasion. Generally speaking, crabs can actively uptake or excrete ions upon salinity change, and the gills play a major role among the osmoregulatory organs. There are several enzymes involved in the osmoregulatory process, including at least Na+, K+-ATPase and H+-ATPase. Na+, K+-ATPase provides the driving force to establish an ion gradient across the epithelial cell membrane in marine crabs. It has been reported that the osmoregulatory mechanisms in the freshwater crabs are different from those of the marine ones and suggested that the driving force may come from H+-ATPase by generating the H+ ion gradient to facilitate the ion flow. I chose 12 species from two families for my experiment. In the first part of my study, I used the immunohistochemistry method to clarify the distribution of H+-ATPase in 12 euryhaline crabs. According to the distribution of H+-ATPase, these 12 crab species can be separated into 3 different groups. The crabs of 1st group had the cytoplasmic H+-ATPase in each gill. The crabs of 2nd group didn’t have a uniform localization of H+-ATPase in each gill or cells in single gill lamellae. The crabs of 3rd group had the apical H+-ATPase in each gill. In the second part of this study, I correlated the location of H+-ATPase with the variation of Na+, K+-ATPase activity among 12 crab species between salinities. The 1st group had a significantly greater Na+, K+-ATPase activity difference than the 2nd and 3rd groups. The crabs from the 1st group that had a greater Na+, K+-ATPase activity differences between salinities were found to have the cytoplasmic H+-ATPase. Those species that had a relatively stable Na+, K+-ATPase activity during salinity fluctuation tended to have an apical distribution of H+-ATPase. The third part of my study is to estimate the H+-ATPase activity of Uca formosensis, the crab that is known to have a stable Na+, K+-ATPase activity. The difference in H+-ATPase activity between salinities was almost significant. The protein level of H+-ATPase was not significantly different between salinities. In conclusion, my results supported the hypothesis that H+-ATPase plays a crucial role in the freshwater adaptation in branchyuran crabs.
| Identifer | oai:union.ndltd.org:TW/092THU00112004 |
| Date | January 2004 |
| Creators | Tsai, Yi-Chieh, 蔡宜潔 |
| Contributors | 林惠真 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 83 |
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