Non-symmetrical cytosine methylation in tobacco pollen DNA

Plant Mol Biol. 1996 Jul;31(4):927-30. doi: 10.1007/BF00019481.


We have detected sequence-specific non-symmetrical cytosine methylation within a 140 bp region of the promoter for the tobacco auxin-binding protein gene T85 in pollen DNA. Direct sequencing of the population of bisulphite reaction products showed that, in this region. 10 out of a possible 49 cytosine residues were methylated at a high frequency in pollen whereas the corresponding region from somatic cells (leaf DNA) did not show a detectable level of methylation. The context of these sites was 1 x m5CpTpC, 1 x m5CpGpT, 1 x m5CpCpT, 2 x m5CpTpT, 2 x m5CpGpG, and 3 x m5CpApT of which only m5CpGpG and m5CpGpT fitted the consensus sequence for symmetrical methylation in plants.

MeSH terms

  • Base Sequence
  • Cytosine / analysis*
  • DNA, Plant / chemistry*
  • Methylation
  • Molecular Sequence Data
  • Plant Growth Regulators*
  • Plant Leaves / metabolism
  • Plant Proteins*
  • Plants, Toxic
  • Pollen / chemistry*
  • Promoter Regions, Genetic / genetics
  • Receptors, Cell Surface / genetics
  • Sequence Analysis, DNA
  • Tobacco / chemistry


  • DNA, Plant
  • Plant Growth Regulators
  • Plant Proteins
  • Receptors, Cell Surface
  • auxin receptor, plant
  • Cytosine