Department of Agronomy, National Taiwan University, No. 1 Sec. 4 Roosevelt Rd., Taipei, Taiwan, ROC.
Plant Mol Biol. 2012 Jul;79(4-5):509-19. doi: 10.1007/s11103-012-9927-9. Epub 2012 May 27.
Insertion of transposed elements into introns can lead to their activation as alternatively spliced cassette exons, an event called exonization, which can enrich the complexity of transcriptomes and proteomes. In this study, the first exonization event was detected when the modified rice EPSPS marker gene was inserted with the Ac transposon 5' end, which provided a splice donor site to yield abundant novel transcripts. To assess the contribution of splice donor and acceptor sites of transposon sequences, we inserted a Ds element into each intron of the EPSPS marker gene. This process yielded 14 constructs, with the Ds transposon inserted in the forward and reverse direction in each of the 7 introns of the EPSPS marker gene. The constructs were transformed into tobacco plants, and novel transcripts were identified by RT-PCR with specific primers. Exonization of Ds in EPSPS was biased towards providing splice donor sites of the inserted Ds sequence. Additionally, when the Ds inserted in reverse direction, a continuous splice donor consensus region was determined by offering 4 donor sites in the same intron. Information on these exonization events may help enhance gene divergence and functional genomic studies.
转座元件插入内含子可导致其作为可变剪接外显子被激活，这一事件称为外显子化，可丰富转录组和蛋白质组的复杂性。在本研究中，当修饰后的水稻 EPSPS 标记基因插入 Ac 转座子 5' 端时，检测到了第一个外显子化事件，这为产生丰富的新转录本提供了剪接供体位点。为了评估转座子序列的剪接供体和受体位点的贡献，我们将 Ds 元件插入 EPSPS 标记基因的每个内含子中。该过程生成了 14 个构建体，其中 Ds 转座子正向和反向插入 EPSPS 标记基因的 7 个内含子中的每一个。将这些构建体转化为烟草植物，并使用特异性引物通过 RT-PCR 鉴定新的转录本。Ds 在 EPSPS 中的外显子化偏向于提供插入 Ds 序列的剪接供体位点。此外，当 Ds 反向插入时，通过在同一内含子中提供 4 个供体位点确定了连续的剪接供体一致序列。这些外显子化事件的信息可能有助于增强基因分化和功能基因组研究。
