a, Introns that accumulate in the stationary phase (increased), and those that did not increase or decrease (not increased), are indicated. Intron abundance was considered to be increased when the transcripts per million (TPM) of introns at 48 h increased by more than 1.5× the TPM detected in log phase. b, The ratio of spliced and unspliced mRNA was calculated in cells that lack the MMS2 or YSF3 intron, in the log phase and stationary phase of growth; the per cent of introns is shown. c, The number of introns that accumulate or decrease upon the deletion of either MMS2 or YSF3 introns (or with both deletions) is indicated, for the log phase and stationary phase of growth. The pie charts shown are a descriptive representation of the data obtained by RNA sequencing, and the data that were validated using RT–qPCR (for example, see Fig. 3c and Supplementary Table 7). d, Intron deletion increases the splicing of RPGs. The intron accumulation of eight RPGs that display enhanced splicing upon the deletion of MMS2 or YSF3 introns is shown. Relative intron accumulation was determined between Δi and wild-type strains in stationary phase of growth as described in b. e, MMS2 introns were deleted in wild-type cells, and in cells that express temperature-sensitive alleles of the splicing factors PRP4 or PRP11 or express the RPG transcription factor IFH1 from an inducible promoter; these cells were tested for growth in low-dextrose medium at the semi-permissive temperature. The relative growth was calculated by subtracting the optical density at 660 nm (OD 660 nm ) after 96 h of growth of the Δi or double-mutant strains from that of the wild-type or the single-mutant strains, respectively. The growth assays were repeated independently three times with similar results. Differences between groups were calculated using a two-sided t-test assuming unequal variances. **P = 0.0044. This figure is related to Figs. 3, 4. Source Data