Molecular Genetics and Genomics

, Volume 265, Issue 4, pp 647–653

Silencing of antibody genes in plants with single-copy transgene inserts as a result of gene dosage effects

Authors

  •  C. De Wilde
    • Departments of Molecular and Plant Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
  •  N. Podevin
    • Departments of Molecular and Plant Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
  •  P. Windels
    • Department of Genetics and Breeding, Centre of Agricultural Research-Gent, Caritasstraat 21, 9090 Melle, Belgium
  •  A. Depicker
    • Departments of Molecular and Plant Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium
Original Paper

DOI: 10.1007/s004380100458

Cite this article as:
De Wilde, C., Podevin, N., Windels, P. et al. Mol Gen Genomics (2001) 265: 647. doi:10.1007/s004380100458

Abstract.

The stability of Fab antibody fragment expression during plant development was studied using two homozygous Arabidopsis thaliana lines that contain single copies of the transgenes. These lines exhibited expression characteristics that are typical for homology-based post-transcriptional gene silencing. Their developmental silencing profiles differed markedly, presumably due to the influence of the genomic context on the T-DNAs. In both lines, a clear gene dosage effect could be observed: in contrast to the homozygous lines, derived hemizygous plants accumulated high levels of Fab fragments throughout development. Interestingly, silencing also occurred in double-hemizygous plants, which resulted from a cross between the two homozygous lines and had two copies of each T-DNA at non-allelic positions in their genome. In all cases, down-regulation of the Fab levels was strictly correlated with methylation of cytosine residues in the transcribed regions of the transgenes. Remarkably, this methylation was also found in regions in which the transgenes were non-homologous regions. Finally, the time point of down-regulation depended on the culture conditions and differed for leaves and roots of the same transgenic plant.

Gene dosage Single-copy inserts Transgene silencing Threshold level

Copyright information

© Springer-Verlag 2001