Zinc finger nuclease-mediated transgene deletion

Plant Mol Biol. 2010 Aug;73(6):617-28. doi: 10.1007/s11103-010-9641-4. Epub 2010 May 8.

Abstract

A transgene, flanked by zinc finger nuclease (ZFN) cleavage sites, was deleted from a stably transformed plant by crossing it with a second plant expressing a corresponding ZFN gene. A target construct, containing a GUS reporter gene flanked by ZFN cleavage sites, a GFP reporter gene and a PAT selectable marker gene, was transformed into tobacco. Basta-resistant plants were regenerated and screened for GUS and GFP expression. A second construct, containing a ZFN gene driven by the constitutive CsVMV promoter and an HPT selectable marker gene, was also transformed into tobacco. Selected T(0) plants were grown to maturity and allowed to self-pollinate. Homozygous target plants, which expressed GUS and GFP, were crossed with homozygous ZFN plants, which expressed the ZFN gene. Numerous GUS-negative plants were observed among the hybrids with one particular cross displaying approximately 35% GUS-negative plants. Evidence for complete deletion of a 4.3 kb sequence comprising the GUS gene was obtained and sequence confirmed. Co-segregation in F(2) progenies of 'truncated' and 'intact' target sequences with expected reporter gene phenotypes were observed. Since ZFNs can be designed to bind and cleave a wide range of DNA sequences, these results constitute a general strategy for creating targeted gene deletions.

MeSH terms

  • Base Sequence
  • Blotting, Southern
  • Crosses, Genetic
  • Endonucleases / genetics
  • Endonucleases / metabolism*
  • Glucuronidase / genetics
  • Glucuronidase / metabolism
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Molecular Sequence Data
  • Nicotiana / genetics
  • Nicotiana / metabolism
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Sequence Deletion / genetics*
  • Sequence Homology, Nucleic Acid
  • Transgenes / genetics*
  • Zinc Fingers*

Substances

  • Green Fluorescent Proteins
  • Endonucleases
  • Glucuronidase