Figure 4.

TDDOs provoke chimeric genes formation. (A–C) Schematic representation of TDDO1, TDDO3, and TDDO4 that provoked TE and/or gene fusion in the 20rDNA L6F6. Genes or TEs present in the breaking junction and their orientation are shown. (D–F) Open reading frames (ORFs) potentially generated at the breaking points. TDDO1 provokes the fusion of the first exon of AT1G55325 that encodes for an ATPase motif of MEDIATOR 13 and the last four exons of AT1G54770 that contain an RNA processing domain (D). The chimeric gene created between AT2G37520 and AT2G38460 potentially encodes for a truncated FERROPORTIN protein (E). The breaking points at TDDO4 fuse the 5′ sequence of a TE (AT4G02960) with the second and last exon of the gene AT4G05475, which sequence encodes two Leucine Rich Repeats (LRR) (F). (G,H) PCR was performed with primers flanking the breaking junctions of TDDO1, TDDO3, and TDDO4 in the wild-type Col-0, the two mutants fas1-4 (G5) and fas2-4 (G5), and in 20rDNA lines L6 (generations F6 and F8) and L9 (generation F7). All PCR products were confirmed by Sanger sequencing. Genomic DNA (G) and cDNA (H) were used as templates. Amplicons from the locus encoding the elongation factor EF1ALPHA was used as a loading control.