Possible Origin and Role of Nuclear Introns

核内含子的可能起源和作用

• 批准号: 9420422
• 负责人: L. Curtis Hannah
• 金额: $ 26.63万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-01 至 1997-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9420422&HistoricalAwards=false
• 关键词: Possible; Origin; Role; Nuclear; Introns

9420422 Hannah Can transposable elements give rise to functional introns? This laboratory has recently demonstrated that the maize transposable element, dissociation (ds) and one copy of the duplicated host sequence can be spliced precisely from the from the primary transcript. In effect, the Ds element has created an intron. A working model of the "intron-late" hypothesis has thus been created and will be tested and characterized by determining the effects of surrounding sequences on Ds splicing, determining the sequence requirements of the 8 bp host duplication on Ds splicing, determining whether fit to consensus of exon/intron borders is needed for Ds splicing and determining whether the Ds-turned intron confers any change on the gene. %%% A controversy exists as to whether introns, sequences which although transcribed from the DNA of (primarily) eukaryotic cells are spliced out to create a functional message, were created early in evolutionary history and served the purpose of providing flexibility in the creation of genes by providing "movable cassettes" or whether they are simply sequences which have been randomly inserted into genes late in evolutionary history and serve no functional purpose. The characterization of a known and well described transposable element in corn as a newly created intron would lend support to the "intron-late" theory. ***

9420422汉娜：转座元件能产生功能内含子吗？该实验室最近证明了玉米转座元件、解离(DS)和复制的宿主序列的一个拷贝可以从初级转录本中准确地拼接出来。实际上，ds元素创建了一个内含子。“内含子-晚期”假说的工作模型已经建立，并将通过确定周围序列对DS剪接的影响、确定8个碱基的宿主复制对DS剪接的序列要求、确定DS剪接是否需要符合外显子/内含子边界的共识以及确定由DS转变的内含子是否使基因发生任何变化来检验和表征该模型。存在争议的是，内含子序列虽然是从(主要)真核细胞的DNA转录而来的，但被拼接起来产生功能信息，是在进化史早期被创造出来，并通过提供“可移动的盒式磁带”来提供基因创造的灵活性的目的，还是它们仅仅是在进化史后期被随机插入到基因中而没有功能目的的序列。玉米中一种已知的、被广泛描述的转座元素被描述为新产生的内含子，这将为“内含子-晚期”理论提供支持。***