Central nodes colored in red, green, blue, or light purple represent the CIN (BiM, ALF, CTF) and RNA-processing screens, respectively. Arrows that project from the central nodes point toward the mutants that were positive in a specific screen. Small circles colored in blue represent ts mutants with unknown function that were defective for CIN or RNA processing at semipermissive temperature. The ORFs that were used as controls for the CIN assay were colored in red. SSU components isolated bicohemically while this work was in progress are colored purple.