Figure 3.

Transcripts with increased read density post-TES in pol IV or pol V mutant plants exhibit a longer termination zone. (A) Schematics of the circular RT-PCR approach used for independent confirmation of transcript ends. (B) Circular RT-PCR results for At5g24670 and At5g36700. Top panels show PCR products obtained using primers placed near transcription start sites (TSS). Bottom panels show both mature and 3'-extended PCR products. Primers for each PCR reactions are color-coded as in (A) and are shown on the right. (C) Sequencing results for cloned At5g24670 PCR products (from B, bottom panel). Number of clones supporting transcript ends at the marked (vertical dashed lines) genomic positions are shown for Col-0, nrpd1, and nrpe1 plants. Numbers on the right represent observed increase (in nt) in the length of the transcripts relatively to mature transcripts. Significance has been tested using one-tailed Chi-square test.