Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain.
Microbiol Spectr. 2016 Dec;4(6). doi: 10.1128/microbiolspec.FUNK-0008-2016.
RNA interference (RNAi) is a mechanism conserved in eukaryotes, including fungi, that represses gene expression by means of small noncoding RNAs (sRNAs) of about 20 to 30 nucleotides. Its discovery is one of the most important scientific breakthroughs of the past 20 years, and it has revolutionized our perception of the functioning of the cell. Initially described and characterized in Neurospora crassa, the RNAi is widespread in fungi, suggesting that it plays important functions in the fungal kingdom. Several RNAi-related mechanisms for maintenance of genome integrity, particularly protection against exogenous nucleic acids such as mobile elements, have been described in several fungi, suggesting that this is the main function of RNAi in the fungal kingdom. However, an increasing number of fungal sRNAs with regulatory functions generated by specific RNAi pathways have been identified. Several mechanistic aspects of the biogenesis of these sRNAs are known, but their function in fungal development and physiology is scarce, except for remarkable examples such as Mucor circinelloides, in which specific sRNAs clearly regulate responses to environmental and endogenous signals. Despite the retention of RNAi in most species, some fungal groups and species lack an active RNAi mechanism, suggesting that its loss may provide some selective advantage. This article summarizes the current understanding of RNAi functions in the fungal kingdom.
RNA 干扰 (RNAi) 是一种在真核生物(包括真菌)中保守的机制,通过大约 20 到 30 个核苷酸的小非编码 RNA(sRNA)来抑制基因表达。它的发现是过去 20 年最重要的科学突破之一,彻底改变了我们对细胞功能的认识。RNAi 最初在粗糙脉孢菌中被描述和表征,在真菌中广泛存在,这表明它在真菌界中发挥着重要作用。已经在几种真菌中描述了几种与 RNAi 相关的机制来维持基因组完整性,特别是保护免受外源核酸(如移动元件)的侵害,这表明这是 RNAi 在真菌界中的主要功能。然而,越来越多的具有特定 RNAi 途径产生的调节功能的真菌 sRNA 已被鉴定。这些 sRNA 的生物发生的几个机制方面是已知的,但它们在真菌发育和生理学中的功能很少,除了一些显著的例子,如卷枝毛霉,其中特定的 sRNA 明显调节对环境和内源性信号的反应。尽管大多数物种保留了 RNAi,但一些真菌类群和物种缺乏活跃的 RNAi 机制,这表明其缺失可能提供了一些选择优势。本文总结了 RNAi 在真菌界中的功能的现有认识。