Yeast survives after all 300 known spliceosomal introns are removed

Spliceosomal introns are noncoding DNA sequences located between exons in many eukaryotic protein-coding genes. Most are removed post-transcriptionally by RNA splicing and do not encode proteins, but they have been implicated in various regulatory processes, including gene transcription, mRNA nuclear export and the generation of protein diversity. Whether spliceosomal introns are essential for fundamental cellular life has long been unclear.