Fig. 5. The dTph1 transposon is inserted in the coding region of the PhMYB1 gene. (A) Agarose gel stained with ethidium bromide showing the bands obtained by PCR amplification of the PhMYB1 sequence from genomic DNA of six unstable phmyb1 lines. The difference in size between the lower and the upper bands corresponds to the size of dTph1. (B) Diagram of the phmyb1 allele showing the position of the transposon insertion. Hatched boxes represent introns. The blue boxes correspond to the R2R3 MYB domain and the stippled box corresponds to the conserved region in the C-terminal domain that identifies subgroup 9 within the R2R3 MYB gene family. This region comprises two conserved stretches of 10 and 22 amino acids; dTph1 (purple box) is inserted in the second one, where it introduces a stop codon into the phmyb1 open reading frame.