Abstract Spliceosomal introns, which have been found in most eukaryotic genes, are non-coding sequences excised from pre-mRNAs by a special complex called spliceosome during mRNA splicing. Introns occur in both protein- and RNA-coding genes and can be found in coding and untranslated gene regions. Because intron sequences vary greatly due to a high rate of polymorphism, the functions of intron had been for a long time associated only with alternative splicing, while intron evolution had been viewed not as an evolution of an individual genomic element, but rather considered within a framework of the evolution of the gene intron-exon structure. Here, we review the theories of intron origin, evolutionary events in the exon-intron structure, such as intron gain, loss, and sliding, intron functions known to date, and mechanisms by which changes in the intron features (length and phase) can affect the regulation of gene-mediated processes.

中文翻译：

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剪接体内含子：特征、功能和进化

摘要 在大多数真核基因中发现的剪接体内含子是在 mRNA 剪接过程中被称为剪接体的特殊复合物从前 mRNA 中切除的非编码序列。内含子存在于蛋白质和 RNA 编码基因中，并且可以在编码和非翻译基因区域中找到。由于内含子序列因高多态性而差异很大，长期以来内含子的功能仅与可变剪接相关，而内含子进化并未被视为单个基因组元件的进化，而是考虑在一个基因内含子-外显子结构进化的框架。在这里，我们回顾了内含子起源的理论，外显子-内含子结构中的进化事件，例如内含子增益、丢失和滑动，迄今为止已知的内含子函数，