Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai, 200032, China.
University of Chinese Academy of Sciences, Shanghai, 200032, China.
Nat Commun. 2020 Nov 5;11(1):5608. doi: 10.1038/s41467-020-19451-z.
The minor spliceosome is evolutionarily conserved in higher eukaryotes, but its biological significance remains poorly understood. Here, by precise CRISPR/Cas9-mediated disruption of the U12 and U6atac snRNAs, we report that a defective minor spliceosome is responsible for spinal muscular atrophy (SMA) associated phenotypes in Drosophila. Using a newly developed bioinformatic approach, we identified a large set of minor spliceosome-sensitive splicing events and demonstrate that three sensitive intron-containing neural genes, Pcyt2, Zmynd10, and Fas3, directly contribute to disease development as evidenced by the ability of their cDNAs to rescue the SMA-associated phenotypes in muscle development, neuromuscular junctions, and locomotion. Interestingly, many splice sites in sensitive introns are recognizable by both minor and major spliceosomes, suggesting a new mechanism of splicing regulation through competition between minor and major spliceosomes. These findings reveal a vital contribution of the minor spliceosome to SMA and to regulated splicing in animals.
在高等真核生物中，小核体在进化上是保守的，但它的生物学意义仍知之甚少。在这里，我们通过精确的 CRISPR/Cas9 介导的 U12 和 U6atac snRNA 的破坏，报告了一个有缺陷的小核体是导致果蝇中脊髓性肌萎缩症（SMA）相关表型的原因。我们使用新开发的生物信息学方法，鉴定了一大批小核体敏感的剪接事件，并证明了三个敏感的内含子神经基因 Pcyt2、Zmynd10 和 Fas3，直接有助于疾病的发展，这可以从它们的 cDNA 能够挽救肌肉发育、神经肌肉接头和运动相关的 SMA 相关表型中得到证明。有趣的是，敏感内含子中的许多剪接位点都能被小核体和大核体识别，这表明通过小核体和大核体之间的竞争来调节剪接的新机制。这些发现揭示了小核体对 SMA 和动物中调节剪接的重要贡献。
