中国科学院分子细胞科学卓越创新中心周金秋小组取得一项新突破。他们的研究开发出了通过完全去除内含子产生的剪接体非依赖性真核生物。这一研究成果发表在2026年7月15日出版的国际学术期刊《细胞》上。
剪接体内含子对真核生物造成了普遍的加工负担，并阻碍了基因组的最小化，因为它们的重要性尚未得到解决。利用合成的单染色体酿酒酵母（Saccharomyces cerevisiae）的Spo11独立减数分裂，实现了所有300个剪接体内含子的完全缺失，产生了一个无内含子的菌株SYNE27α。全基因组测序证实了精确切除。出乎意料的是，剪接体成分（所有五种小核RNA [snoRNA]， Prp8, Prp9, Prp19， Yhc1和Luc7）不再需要生存，这表明真核细胞可以独立于剪接体功能而存在。
U3小核核RNA （snoRNA）剪接绕过了Yhc1、Luc7、Prp9和Prp19的要求，揭示了与pre-mRNA剪接的机制差异。累积内含子丢失通过核糖体失调导致生长缓慢，而SYNE27α维持遗传稳定性。适应度成本在二倍体中是完全隐性的，证实内含子丢失是主要驱动因素。这些发现建立了一个无内含子、剪接体独立的真核生物，解决了剪接体的基本功能，并使基因组进化的最小系统研究成为可能。
附：英文原文
Title: A spliceosome-independent eukaryote generated by complete intron removal
Author: Xin Man, Wen-Ting Zhang, Yu-Di Zhang, Qian-Xi Li, Pengfei Dai, Weimin Jiang, Jin-Qiu Zhou
Issue&Volume: 2026-07-15
Abstract: Spliceosomal introns impose a universal processing burden on eukaryotes and obstruct genome minimization because their essentiality remains unresolved. By exploiting Spo11-independent meiosis in synthetic single-chromosome Saccharomyces cerevisiae, the complete deletion of all 300 spliceosomal introns was achieved, generating an intron-free strain, SYNE27α. Whole-genome sequencing confirmed precise excision. Unexpectedly, spliceosomal components (all five small nuclear RNAs [snRNAs], Prp8, Prp9, Prp19, Yhc1, and Luc7) were no longer required for viability, demonstrating that a eukaryotic cell can exist independently of spliceosomal function. U3 small nucleolar RNA (snoRNA) splicing bypassed the requirements for Yhc1, Luc7, Prp9, and Prp19, revealing a mechanistic divergence from pre-mRNA splicing. Cumulative intron loss caused slow growth via ribosomal dysregulation, yet SYNE27α maintained genetic stability. Fitness costs were fully recessive in diploids, confirming intron loss as the primary driver. These findings establish an intron-free, spliceosome-independent eukaryote, resolving the essential function of the spliceosome and enabling minimal-system studies of genome evolution.
DOI: 10.1016/j.cell.2026.05.033
Source: https://www.cell.com/cell/abstract/S0092-8674(26)00624-0