Figure 4

Polyadenylation sites of P1-wr[B73] , P1-rr4B2 and p2. Figures A to C display the partial 3' UTR sequences of P1-wr, p2 and P1-rr, respectively. Numbers on the x-axis refer to the nucleotide position after the stop codon. The y-axis reflects the percentage of transcripts that were polyadenylated at each nucleotide. (A) P1-wr[B73] polyadenylation sites. 18 polyadenylation sites are shown for P1-wr transcripts isolated from pericarp tissue. The most frequently used polyadenylation sites are 298 nt and 301 nt downstream of the stop codon. (B) Polyadenylation sites of p2 are located in a flanking LTR region. The sequence highlighted in yellow belongs to an Eninu retrotransposon that inserted 1.38 mya in p2. The target site duplication (TSD) AAGAC upon insertion is highlighted in green. The first and second bp of the LTR are mutated from TGCTGT to AACTGT. The majority of transcripts are polyadenylated within the LTR sequence. (C) Polyadenylation sites of P1-rr4B2 are located in a flanking MULE sequence. The MULE sequence is highlighted in yellow and the potential TSD in green. Note the sequence gap 161-430 bp after the stop codon, which does not contain any polyadenylation sites. All P1-rr4B2 transcripts are polyadenylated within the transposon.