2009-08-012024-05-16https://scholars.lib.ntu.edu.tw/handle/123456789/668991摘要：使用篩選標記基因(SMG&#1049497;selectable marker genes)可以快速、有效率的篩選出轉殖株。然而在 獲得轉殖株後，篩選標記基因就無特殊用途，並有生物安全疑慮。針對移除篩選標記，目前 被廣泛認可的有cre/lox 系統及轉位子系統，前者有時造成非專一性DNA 互換；本計畫擬利 用轉位子系統之優點：移除機制具專一性，而移除之篩選標記所在位置可清楚提供基改審查。 先前，申請人選殖出水稻之EPSPS 基因並改造成可抗嘉磷塞（即轉基因篩選標記），該基因 合併先前開發之「可誘導轉位子」構築成新載體（轉位子之一端建構於EPSPS 基因之intron 中）；此載體轉入作物時以嘉磷塞篩選成功之轉基因植株，其後誘導轉位子跳離，由於轉位子 含了一部份EPSPS 基因，跳離後破壞了EPSPS 基因讀序，因而移除篩選標記功能。本計畫 延伸類似概念應用於轉位子—將轉位子另一端點建構於轉位&#37238;之intron 中，而成一次轉位之 轉位子，並終止篩選標記之功能。本計畫所開發之技術之進步性為：1. 新系統之轉位子受到 調控，即誘導後才轉位；2. 在轉基因效率低之作物中因轉位而自動創造許多轉殖系；3. 舊系 統無法應用於無性繁殖作物。香蕉為東南亞重要經濟作物，本計畫將以香蕉及水稻（模式植 物）為材料，開發成功後除申請專利，並可向東南亞國家（如印尼）推廣。<br> Abstract: Since the maize transposon Ac can move to a new location within the genome, it has been used in removing selectable marker genes (SMGs) in transgenic plants. Previously, we developed an inducible transposon system to truncate a selectable marker in transgenic plants. In this system, the marker gene was accompanied by the inducible transposon, but one end of the transposon was located in the intron of the marker gene. As an example of a marker gene, we isolated the rice 5-enolpyruvylshikimate-3-phosphate synthase (epsps) and modified it for glyphosate tolerance. The transposon contained Ac transposase, which fused with the promoter of the inducible gene for pathogenesis-related protein 1a (PR-1a). The construct was applied to rice transformation using glyphosate as the selective agent. We demonstrate that the modified epsps could be a suitable selectable marker to create transgenic rice. Furthermore, after obtaining stable transgenic plants and inducing transposition by salicylic acid, the transposon was excised, the marker gene became truncated and its expression was terminated. This strategy could be applicable to yield self-stabilizing transposon by locating the transposon’s end in the transposase gene’s intron. In this project, new one-step inducible transposons would be constructed to terminate the SMG as well as transposase. In addition to the modified epsps as the SMG, the well used HPT (Hygromycin phosphotransferase) gene would be modified to harbor an intron, which contains one Ac end. The invention is most applicable to vegetatively propagated plants and woody tree species. Therefore, the transposons would be transformed into rice (as a model plant) and banana, which are important economic crops in south Asia.轉基因作物篩選標記基因可誘導轉位子轉位&#37238transgenic cropsselectable marker genesinducible transposonAc transposase