Figure 1.

Genomic organization of transgenic loci. Transgenic locus 1 contains two copies of the T-DNA organized as an inverted repeat; transgenic locus 2 encompasses one T-DNA copy. The distance between right (RB) and left (LB) border is ∼5 kb in locus 1 and locus 2. There is a hygromycine resistance gene between the LB and the nptII gene. Restriction sites used for methylation analysis were TaiI (T), Sau96I (S) and BclI (B). A thick P bar indicates region of probe hybridization. M and E bars correspond to PCR fragments used for bisulfite and expression analysis, respectively. Silencing trigger locus 271 comprises several transgene copies, some of them being incomplete. P35S, P19S: promoters from the cauliflower mosaic virus; nptII: bacterial neomycin phosphotransferase II gene; RiN: inverted copy of the tobacco nitrite reductase gene.