ADARs convert adenosines to inosine in either coding or noncoding region of double-stranded RNA. The inosine is interpreted as guanosine during posttranscription processing and translation. In addition, the pairing properties of inosine differ form that of adenosine, ADARs can also affect the secondary structures of transcripts. Consequently, ADARs may change the coding potential, splicing, RNA processing, stability, and translation efficiency of primary transcripts and mRNA.
Site-specific adenosine deamination of RNA editing alters codon of pre-mRNA for glutamate receptor (GluR) subunits in the CNS (central nervous sytem), including a channel determinant codon (Q/R site) in GluR-B, which is associated with the Ca2+ permeability of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors (Melcher et al., 1996). Both edited and unedited variations of the kainite-receptor subunits GluR6 are present in brain As to GluR6, the Q/R site is predominantly edited, and the Y/C site is edited similar to the Q/R site extent, while the I/V site is less edited. There are three different ADAR enzymes characterized in mammals, ADAR1, ADAR2, and ADAR3. This thesis employed the quantitative PCR analysis to study the effects of ADAR2 knockout on the editing of Y/C site of kainate receptor and whole-amount in situ hybridization to study the ADAR2-like gene, zCh9, expression during zebrafish embryo development. Our results suggested that editing efficiencies of the Y/C site were influenced when ADAR2 was knockout and the zCh9 was mainly expressed in the CNS.

ADAR是一種可以將核醣核酸(RNA)中的編碼(coding)或非編碼(noncoding)序列藉由脫胺反應(deamination)將腺苷(adenosine)轉變成肌苷(inosine)，進而改變基因編碼、序列轉譯、RNA 序列修飾(processing and splicing)和穩定度，以及mRNA 轉譯效能的酵素。受腺苷脫胺(adenosine deamination)酵素修飾的mRNA包含中樞神經系統中的離子型通道(iontropic channel)的麩胺酸受器(glutamate receptor)，尤其是哺乳動物此類受器GluR2次單元的特定Q/R 位點已被確認為受ADAR2之特定位點的編輯(editing)。本論文以ADAR2 antisense morpholino(針對ADAR2 5’UTR區域)抑制ADAR2表現，以即時定量聚合酶鏈式反應(real-time quantitative polymerase chain reaction)研究ADAR2對另一肤胺酸受器次單元GluR6的特定位點Y/C位點編輯以及斑馬魚胚體發育的影響；並以即時定量聚合酶鏈式反應(real-time quantitative polymerase chain reaction)及全覆式原位雜合染色(whole-amount in situ hybridization)研究斑馬魚基因組中另一結構類似ADAR2的基因─zCh9在斑馬魚胚體發育過程中的表現圖譜。我們觀察到18hpf及24hpf的adar2 morphant 中Y/C 位點的editing較野生型斑馬魚低，而經由ADAR2 cRNA rescue的adar2 morphant 18hpf及24hpf胚體在Y/C site的editing對於野生型會相對提高。我們透過胚體全覆式原位雜合染色顯示zCh9 表現集中在斑馬魚24hpf,48hpf以及72hpf胚體腦部。本研究顯示抑制ADAR2表現會影響Y/C site editing，以及zCh9的表現在斑馬魚胚體發育過程集中在胚體腦部。

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