碩士 / 國立陽明大學 / 生理學研究所 / 90 / Syndecan-2 is a member of the syndecan family of transmembrane heparan sulfate proteoglycans and it can bind to a variety of biological substrates involved in cell proliferation and differentiation. Zebrafish is a good model organism to study the function and developmental regulation of novel genes, because its embryos are easily observed since they are transparent. In this study, the syndecan-2 gene from zebrafish (z-Syn2) was isolated and characterized in vitro and in vivo. The full-length cDNA of z-Syn2 contains 747 bp and encodes a protein of 208 amino acids. From the amino acid sequence comparison, z-Syn2 is 48% identical to Xenopus laevis, 45% to mouse, and 46% to human The transmembrane and cytoplasmic domains of syndecan-2 are highly conserved in these species. To examine the function of syndecan-2, we performed transfection study in COS-1 cells. Western blot of cell lysate showed that the product of z-Syn2 is a 27 kDa protein. By immunocytochemistry, z-Syn2 protein is co-localizeted with endoplasmic reticulum, Golgi and actin. Overexpression of z-Syn2 reduced cell viability. When DNA was extracted from the cells transfected with z-Syn2 and analyzed by agarose gel electrophoresis, a ladder pattern of discontinous DNA fragments was observed, suggesting that these cells were undergoing apoptosis.
During the development of the zebrafish, syndecan-2 mRNA is continuous present. The Northern blot demonstrated that syndecan-2 mRNA is expressed in adult brain, gill, heart, muscle and ovary. In addition, we also investigated the gain or loss of function of syndecan-2 gene during zebrafish development. To study the loss of function of syndecan-2 gene, we injected morpholino antisense oligonucleotides of syndecan-2 into the zebrafish embryos to inhibit the translation of syndecan-2. Three days postfertilization, the ventricle of zebrafish brain had obvious defects with swelling. In the gain of function study, we injected syndecan-2 mRNA into the zebrafish embryos at one-cell stage. Consequently, the mutant embryos exhibit abnormal eyes, brains, hearts, and skeleton. In summary, the in vitro and in vivo data suggest that syndecan-2 may play very important roles in the organogenesis during zebrafish development.
| Identifer | oai:union.ndltd.org:TW/090YM000116012 |
| Date | January 2002 |
| Creators | 呂宜瑾 |
| Contributors | 周韻家 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 58 |
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