Silencing of tandem transgenes in potato

Transgene expression stability is a critical point in applications of transgenic plants. Nocarova et al. study long-term changes in transgene expression in potato, Solanum tuberosum. Silencing of two introduced reporter genes (GFP and NPTII) is successive in all registered cases (in about 25 % lines), indicating an interconnection between their silencing that could be interpreted as a switch of GFP silencing from the post-transcriptional to transcriptional level and subsequent spreading of methylation to the NPTII gene.