Possible Origin and Role of Nuclear Introns

9420422转座因子能产生功能性内含子吗？本实验室最近证明玉米转座因子、解离因子（ds）和复制宿主序列的一个拷贝可以精确地从初级转录本中剪接出来。实际上，Ds元素已经创建了一个内含子。一个工作模型的“内含子-晚期”的假设，因此已经创建，并将进行测试和表征，确定周围序列的影响Ds剪接，确定的8 bp的主机复制Ds剪接的序列要求，确定是否适合的共识外显子/内含子边界是需要Ds剪接，并确定是否Ds-转向内含子赋予任何变化的基因。 对于内含子是否存在争议，内含子，尽管是从DNA转录的序列，（主要）真核细胞被剪接以产生功能性信息，在进化史的早期就被创造出来，并通过提供“可移动的盒”来为基因的创造提供灵活性。或者它们是否仅仅是在进化历史后期随机插入基因中的序列，没有任何功能。玉米中一个已知的和被充分描述的转座因子被表征为一个新产生的内含子，这将支持“内含子-晚期”理论。 ***

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. ***