Fig. 6

Similar post-transcriptional process in R17 region was observed in CMS-Sa and CMS-Sb. a Diagrammatic representation of nad1 and nad2 RNA transcripts that generated from post-transcriptionally processing of the precursor. b and c The cropped gels of cRT-PCR products of nad1-transcripts 1 (b) and nad2-transcripts 2 (c). “+” indicated RNA samples treated with RNA 5′-polyphosphatase. d Schematic map of two copies of R17 in CMS-Sb. Circular RT-PCR (cRT-PCR) in CMS-S revealed that nad1-exon1 were processed downstream of trnP to generate the 5′ terminus and upstream of mtpt sequence to generate the 3′ terminus. No obvious difference was observed in the fragment length and processing site of cRT-PCR products between subtype CMS-Sa and CMS-Sb, which due to the presence of intact first copy of R17 is both genomes. cRT-PCR analysis revealed similar precursor of nad2-exon3, exon4, and exon5 that flanking border of the first copy of R17. Consistent with previous work of Zhang et al, no specific precursor that flanking nad2-exon4 and exon5 in the second copy of R17 were identified, which probably due to low abundance of this precursor