Plant Cell Reports

, Volume 22, Issue 12, pp 939–944 | Cite as

Quantitative determination of mosaic GFP gene expression in tobacco

  • M. T. Bastar
  • Z. Luthar
  • S. Škof
  • B. Bohanec
Genetics and Genomics


A specific form of gene silencing that was observed visually as a mosaic distribution of fluorescent and non-fluorescent cells apparently dispersed at random within tissues was found in a few green fluorescent protein (GFP)-transformed tobacco lines. To characterize this event quantitatively, we studied flow cytometric measurements in GFP-expressing and -silenced cells in T1 and T2 progeny of four selected plants. The proportion of silenced cells varied considerably among the T1 lines but with notable genotype differences. Mosaic expression was inherited into the T2 generation in which the majority of progenies tested exhibited a level of silencing similar to that of their T1 parental plants. However, in some T2 progenies segregation, evident as a decrease or increase in the proportion of fluorescent cells, was observed. We discuss several factors, such as copy number, promoter activity or polyploidy, that may be the possible causes of the gene silencing, but none sufficiently explain the appearance of the mosaic distribution.


Nicotiana tabacum Mosaic gene expression Green fluorescent protein Flow cytometry 



The authors are indebted to Dr. Michael J. Havey and Mark Petrashek for their help with Southern blotting analysis performed at the University of Wisconsin, Madison, Wis., USA.


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • M. T. Bastar
    • 1
  • Z. Luthar
    • 1
  • S. Škof
    • 1
  • B. Bohanec
    • 1
  1. 1.Biotechnical FacultyUniversity of LjubljanaLjubljanaSlovenia

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