碩士 / 國立清華大學 / 分子與細胞生物研究所 / 99 / ADAR2 is a member of the ADARs (Adenosine deaminase that acts on RNAs) protein family. ADAR2 can post-transcriptionally edit specific adenosine at double-stranded RNA region into inosine (A-to-I RNA editing), and increase the complexity of transcriptome. Two paralogues of ADAR2 have been discovered in the pufferfish (Takifugu rubripes). Using bioinformatic tools, a gene ADAR2β whose sequence is conserved to ADAR2α was found on the 9th chromosome of zebrafish. The RT-PCR analysis showed that ADAR2β was expressed in adult zebrafish brain. In addition, overexpression of ADAR2β (ADAR2β cRNA microinjection into one-cell zygote) can increase the RNA editing level of ADAR2α pre-mRNA. In order to examine the physiological functions of ADAR2α and ADAR2β, we employed antisense morpholinos targeted to ADAR2α and ADAR2β to reduce the expression of these genes. The phenotypes, distribution of apoptotic cells and posterior lateral line neuromasts of mophants indicated that the phenotype of ADAR2β morphant was the same as that of the wild type but different from that of ADAR2α morphant. These results suggested that the physiological functions of ADAR2α and ADAR2β differed. Genetic studies have indicated that the Q/R site of mouse GluR2 (AMPA receptor subunit) is the most important physiological substrate of ADAR2. Therefore, we also made use of a morpholino to suppress the Q/R editing of gira2α?n(homologue of mammalian GluR2) to observe if Q/R site of zebrafish gria2α?nis also the key site edited by ADAR2. The results showed that both ADAR2α and gria2α Q/R morphants led to abnormal neural development. In this study, we have demonstrated that ADAR2β is the duplicated gene of ADAR2α, and ADAR2α and ADAR2β can mutually modify the pre-mRNA sequences of each other. In addition, the physiological function of ADAR2α is different from that of ADAR2β. ADAR2β possesses RNA editing activity; however, its physiological function remains to be elucidated.
| Identifer | oai:union.ndltd.org:TW/099NTHU5061006 |
| Date | January 2011 |
| Creators | Chang, Chin-Chuan, 張志泉 |
| Contributors | Chow, Wei-Yuan, 周姽嫄 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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