Mutations in the Med8-Med18-Med20 submodule cause an accumulation of centromeric transcripts. (A) The steady-state level of centromeric non-coding RNA was estimated by RT-PCR in the indicated mutants. The actin transcript was used as reference. (B) RT-qPCR shows that the dh transcript accumulates in med18Δ and med20Δ strains. (C) Strand specific RT-PCR shows that med18Δ and med20Δ strains have wild-type ratios of forward to reverse transcripts. (D) Northern blot analysis shows that the length of major centromeric transcripts is unchanged in the mutants. The strains for this figure were: WT (FY498), med18Δ (MT42), med20Δ (MT26), med8ts (MT31), and dcr1Δ (TP480).