請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/90248
標題: | 時序性新生蛋白合成調節雄性減數分裂的進程 Temporal nascent protein synthesis regulates the progression of male meiotic divisions |
作者: | 陳思妤 Szu-Yu Chen |
指導教授: | 吳瑞菁 Jui-Ching Wu |
關鍵字: | 雄性減數分裂,中心體成熟,中心體複製,抑制轉譯,精子特異性轉譯調節蛋白, male meiosis,centrosome duplication,centrosome maturation,translation inhibition,sperm-specific translation regulator, |
出版年 : | 2023 |
學位: | 碩士 |
摘要: | 初級精母細胞經歷特別的分裂過程,其中連續兩次的染色體分離事件中並無明顯的停頓,為了要了解細胞週期程序如何調節精子發生過程中連續兩次的分裂,我們的目的是研究新生蛋白質合成對雄性減數分裂進展的影響。首先,我們觀察到精子特異性轉譯調節蛋白CPB-1的缺失會讓精母細胞無法進行第一次分裂,從而導致精子生成嚴重缺陷。另外,當用轉譯抑制劑處理初級精母細胞時,細胞能夠成功完成第一次減數分裂,但是未能啟動第二次分裂。這些發現支持兩波轉譯對於精母細胞完成連續兩次分裂至關重要的假說。
我們的研究進一步表明,在轉譯抑制下,紡錘體極在第一次分裂完成後未能重新的被建立。儘管中心粒在用抑制轉譯的情況下能夠正常複製,但中心體未能成熟。另外,我們還發現在轉譯抑制阻斷第一次分裂後,激酶PLK-1未能定位到紡錘體極。此外,抑制PLK-1會導致精母細胞無法進行第二次分裂,中心體成熟也有缺陷,與我們在轉譯抑制觀察到一樣的結果。因此我們認為PLK-1未能定位到中心體是細胞在第一次減數分裂停滯的主要原因。代謝性蛋白質標定(metabolic labeling)表明新生蛋白沒有定位到特定的細胞結構,由此結果我們認為在精子生成過程中需要重建訊號傳遞練以介導兩次減數分裂的發生,此外,銀染和代謝性蛋白質標定表明,CPB-1並不會顯著影響減數分裂期間的整體轉譯水平,此結果加強了CPB-1調控目標蛋白在精子發生的重要性。 Spermatocytes undergo a unique process of division characterized by two consecutive chromosome segregation events without apparent pauses. In order to understand how cell cycle programs regulate the repetition of divisions during spermatogenesis. Our aim was to investigate the impact of nascent protein synthesis on the progression of male meiotic divisions. Our previous study showed that the loss of CPB-1, a sperm-specific translation regulator, resulted in spermatocytes being unable to undergo the first division, leading to a significant defect in spermatogenesis. Furthermore, when primary spermatocytes were treated with translation inhibitors, they were able to complete the first meiotic division (MI) successfully. However, the resulting secondary spermatocytes failed to initiate the second division (MII). These findings support the hypothesis that two waves of translation are crucial for spermatocytes to complete both rounds of division. In this study, I found that under translation inhibition, the spindle poles failed to re-establish after the completion of the MI division. Although the centrioles duplicated normally in primary spermatocytes treated with translation inhibitors, the centrosomes failed to mature. Specifically, polo-like kinase PLK-1 failed to localize to the spindle poles after the MI division under translation inhibition. Moreover, inhibiting PLK-1 resulted in spermatocytes being unable to perform the second division, and centrosome maturation was also defective, similar to the effects observed with translation inhibition. We propose that the failure of PLK-1 to localize to the centrosome is the primary cause of the cell being arrested at meiosis I. Metabolic labeling experiments demonstrated that the nascent proteins did not localize to specific division structures. We hypothesize that the signaling cascade needs to be rebuilt during the transition from MI to MII in spermatogenesis. Additionally, examination of whole worm extracts and metabolic labeling experiments revealed that CPB-1 does not significantly affect global translation levels during meiosis, highlighting the importance of the CPB-1 target protein in spermatogenesis. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/90248 |
DOI: | 10.6342/NTU202303853 |
全文授權: | 未授權 |
顯示於系所單位: | 醫學檢驗暨生物技術學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-111-2.pdf 目前未授權公開取用 | 2.79 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。