FIG. 3.

cwc23_1-225 is defective in pre-mRNA splicing, but cwc23_ΔJ is not. (A) Global analyses of pre-mRNA splicing. For each of 301 intron-containing genes, the behaviors of the total mRNA, pre-mRNA, and mature mRNA were determined (indicated as T, P, and M, respectively, above each lane; see the diagram at top). Each horizontal line describes the behavior of a single intron-containing gene. Ratio values were calculated for each of the strain comparisons. The data are presented as false-colored representations of the log₂ value for each feature. For the cwc23_1-225 experiments, samples were first collected from both mutant and wt strains while growing at 30°C. An additional sample was collected after both strains had been shifted to 16°C for 30 min. For the prp43_Y402A experiment, both mutant and wt strains were grown at 30°C then shifted to 37°C for 30 min prior to sample collection. For the Cwc23_ΔJ experiment, samples were collected from both mutant and wt strains growing at 30°C. (B) cwc23_1-225 accumulates actin lariat-introns. Equal amounts of total RNA isolated from cwc23Δ cells expressing wt Cwc23 (WT), Cwc23_ΔJ (ΔJ), Cwc23_1-225 (1-225) were resolved on denaturing agarose gels, transferred to nylon membrane, and probed with either full-length (left) or intronic (right) actin DNA. Bands were visualized utilizing a PhosphorImager (top panel). p, precursor; m, mature; i, intron lariat. As a loading control, the membrane was stained with ethidium bromide to visualize rRNA (bottom panel).