Introns are ubiquitous in eukaryotic transcripts. They are often viewed as junk RNA but the huge energetic burden of transcribing, removing, and degrading them suggests a significant evolutionary advantage. Ostensibly, an intron functions within the host pre-mRNA to regulate its splicing, transport, and degradation. However, recent studies have revealed an entirely new class of trans-acting functions where the presence of intronic RNA in the cell impacts the expression of other genes in trans. Here, we review possible new mechanisms of intron functions, with a focus on the role of yeast introns in regulating the cell growth response to starvation.

中文翻译：

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内含子：不好的一天垃圾是不好的一天宝藏。

内含子在真核转录本中无处不在。它们通常被视为垃圾RNA，但转录，去除和降解它们的巨大精力负担却显示出巨大的进化优势。表面上，内含子在宿主前mRNA中起作用，以调节其剪接，转运和降解。但是，最近的研究揭示了一类全新的反式功能，其中细胞中内含子RNA的存在会影响反式中其他基因的表达。在这里，我们审查可能的内含子功能的新机制，重点是酵母内含子在调节细胞对饥饿的生长反应中的作用。