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標題: | 探討miRNA bantam-a在渦蟲再生與恆定性中扮演的角色 The Role of miRNA bantam-a in Planarian Regeneration and Homeostasis |
作者: | Yu-Chi Lin 林郁綺 |
指導教授: | 朱家瑩 |
關鍵字: | miRNA,bantam-a,細胞增生,細胞分化,組織恆定性,渦蟲, bantam-a,miRNA,cell proliferation,differentiation,homeostasis,Planarian, |
出版年 : | 2015 |
學位: | 碩士 |
摘要: | MicroRNAs為長度約20-24 核苷酸的小片段非編碼核糖核酸,會與Argonaute蛋白質結合並且形成RNA誘導沉默複合物(miRISC),進行轉錄後的基因調控。在渦蟲的再生過程中,需要成體幹細胞(neoblasts)進行細胞增殖並且分化成各種型態的細胞來維持渦蟲身體的恆定性。研究指出抑制Argonaute的表現會造成渦蟲從頭部開始出現退化的現象,因此推測miRNAs可能會參與維持渦蟲的身體恆定性。在渦蟲再生時,一些特定的miRNAs大量表現於渦蟲再生組織,推測這些miRNAs具有調控渦蟲再生過程中成體幹細胞的功能。本研究著重在了解miRNA bantam-a 在渦蟲中的功能。實驗結果顯示bantam-a大量表現在渦蟲的眼點、中樞神經系統以及再生組織(blastema)。當bantam-a 被抑制時會干擾neoblasts進入到細胞週期中的M phase,以及後代細胞(progeny cell)的生成。長期抑制bantam-a的表現也會造成渦蟲頭部出現不對稱眼點的現象。顯示在neoblasts的細胞複製、自我更新以及分化時都需要bantam-a的參與,以維持渦蟲的組織恆定性。綜合本研究結果,我們證實bantam-a在渦蟲的組織恆定性、成體幹細胞的增生及分化扮演重要的角色。bantam-a會抑制目標基因的表現,並可能透過此機制調控渦蟲的再生。 MicroRNAs, the 20-24 nt small non-coding RNAs, are associated with Argonaute proteins and form miRNA-induced silencing complex (miRISC) to regulate gene expression at post-transcriptional level. Regeneration in planarian is mediated by adult stem cells, called neoblasts, which can proliferate and differentiate into almost all cell types for replacing the whole body. Our preliminary study showed that depletion of planarian Argonaute 2 (DjAgo2) results in a phenotype of severe degeneration, suggesting that miRNAs are required for tissue homeostasis in planarian. A certain population of miRNAs is highly expressed in regenerating tissues, implicates the potential roles of miRNAs in neoblasts during regeneration. In this study, I examined the roles of bantam-a miRNA in planarian. The expression of bantam-a is enriched on the eyespots, central nervous system, as well as in blastema during regeneration. Inhibition bantam-a with specific miRNA inhibitor results in deficiency of tissue homeostasis. This inhibition experiment also showed two phenomena: bantam-a inhibition perturbs neoblasts cell cycle before entering M phase, and alters the produce of progeny cells. In consequence, these results indicated that bantam-a indeed participates in tissue homeostasis, self-renewal of neoblasts and the differentiation process in planarian. Finally, validation of the predicted targets of bantam-a provides evidence to support our hypothesis for bantam-a regulated pathway, and these data also provide insights into the possible mechanisms that underlay the miRNA-mediated gene silencing in regeneration. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/52155 |
全文授權: | 有償授權 |
顯示於系所單位: | 生命科學系 |
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