碩士 / 國立海洋大學 / 水產生物技術研究所 / 90 / Abstract
Zebrafish hoxa1a is a homeobox gene. It encodes a polypeptide including a 60 amino acid homeodomain. Seven diagnostic residues that confering specific DNA binding locate in the homedomain. In addition, there are conserved hexapeptide sequence, WMKVR, that lies 19 or 20 amino acids N-terminal of the homeodoamin. Zebrafish hoxa1a has a splice variant resulting two different length mRNA. Results of whole-mount in-situ hybridization showed that hoxa1a was expressed in the ventral region of both the midbrain and anterior hindbrain neuronal cells. Because of gene regulation mechanism of hoxa1a is not clear, we used transient transgenic analysis to dissect cis-regulatory elements of hoxa1a promoter and 5΄upstream region in this thesis. Four different lengths of 5΄upstream region of hoxa1a were fused with the GFP reporter gene and microinjected into one-cell zebrafish zygotes. Results showed that GFP expression rate of embryos injected with different length of 5΄ upstream sequence including nucleotide -2946/-54bp、-2482/-54bp、-2031/-54bp and -1611/-54bp were 31.97%、32.32%、33.68% and 30.21%, respectively. However, green fluorescence was only observed in the yolk sac. While 5kb hoxa1a 3΄untranslation region was coinjection with GFP constructs containing different length of 5΄upstream region, GFP expression rates were 33.15%、32.83%、33.52% and 30.09%, respectively. There are two different GFP expression pattern：(1)when -2946/-54bp or-2482/-54bp constructs were injected, green fluorescence was observed not only in the yolk sac but also expressed in the neuron、muscle and skin.(2)when- 2031/-54bp or-1611/-54bp constructs were injected, GFP expression was only observed in the yolk sac. These results suggest that DNA segment between —2482bp and —2031bp of hoxa1a 5΄upstream region in combination of hoxa1a 3΄ untranslation region may confer some neuron-specific GFP expression. In addition 5΄-RACE was used to find mRNA transcription start site and we have identified 1.4kb long 5΄ untranslated region.
| Identifer | oai:union.ndltd.org:TW/090NTOU0613015 |
| Date | January 2002 |
| Creators | 林順啟 |
| Contributors | , 胡清華, 黃聲蘋 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 70 |
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