頁籤選單縮合
題名 | Allopolyploidization Induced the Activation of Ty1-copia Retrotransposons in Cucumis hytivus, a Newly Formed Cucumis Allotetraploid=異源多倍化誘導甜瓜屬新合成的異源四倍體Cucumis hytivus中Ty1-copia類逆轉座子的啟動 |
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作者 | 江彪; 婁群峰; 王東; 吳志明; 張萬萍; 陳勁楓; | 書刊名 | Botanical Studies |
卷期 | 52:2 2011.04[民100.04] |
頁次 | 頁145-152 |
分類號 | 434.28 |
關鍵詞 | 逆轉座子; 逆轉錄酶; 異源多倍化; 甜瓜屬; Allopolyploidization; Cucumis; Retrotransposon; Reverse transcriptase; RT-PCR; |
語文 | 英文(English) |
中文摘要 | 異源多倍化是作物進化的一個重要過程,是宿主基因組巨大的“基因組衝擊”。為了研究異源多倍化對C. hytivus逆轉座子表達的影響,我們根據Ty1-copia類逆轉座子逆轉錄酶的保守區設計簡並引物,利用RT-PCR技術從異源四倍體C. hytivus及其二倍體親本C. hystrix和C. sativus中擴增逆轉錄酶基因,結果僅在異源四倍體中擴增出目的片斷。回收測序後,獲得了18個高度異質的克隆。這些克隆彼此不同,至少能夠分為8個家族。同義(dS)和非同義(dN)替換分析表明這些序列受淨化選擇的作用。根據這18個RT序列的氨基酸和從GenBank資料庫中獲得的其它作物序列,利用最大似然法構建進化樹,結果表明這些序列與其它作物存在高度的同源性,表明它們可能有共同起源。進一步對所獲得的逆轉錄酶序列在異源四倍體早期四個世代的表達分析證實,異源多倍化誘導了該類逆轉錄酶的表達。這些發現為多倍體進化提供了重要資訊,並對進一步表觀遺傳學研究具有重要意義。 |
英文摘要 | Allopolyploidy is an important process of species evolution that delivers a huge ‘genomic shock’ to the host genome. To investigate the effect of allopolyploidy on the expression of retrotransposons in a new synthetic allopolyploid, Cucumis hytivus, RT-PCR strategy was carried out to amplify reverse transcriptase (RT) genes from allotetraploid C. hytivus and its diploid parents, C. hystrix and C. sativus, using degenerate oligonucleotide primers corresponding to conserved RT domains of Ty1-copia retrotransposons. Only the allotetraploid yielded a specific product with expected size. After recovering and sequencing, 18 unique clones with significantly high heterogeneity were obtained. All of these clones were different from each other and could be divided into at least eight groups. The synonymous (dS) and nonsynonymous (dN) substitution analysis suggested that the RT sequences had been under constraint or purifying selection. A comparative maximum likelihood (ML) tree was constructed based on the deduced amino acids of the 18 RT sequences and those of other species acquired from the GenBank database. These results showed that the cloned sequences had high homology with both related and unrelated species, implying that they shared a common ancestor. The expression analysis of the cloned reverse transcriptase in the first four generations of allotetraploid further proved that the activation of retrotransposons was induced by allopolyploidization. These findings provide important information for polyploid evolution and will be of great importance for further epigenetic studies. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。