Faithful inheritance of cytosine methylation patterns in repeated sequences of the allotetraploid tobacco correlates with the expression of DNA methyltransferase gene families from both parental genomes.

摘要: The widespread occurrence of epigenetic alterations in allopolyploid species deserves scrutiny that DNA methylation systems may be perturbed by interspecies hybridization and polyploidization. Here we studied the genes involved Nicotiana tabacum (tobacco) allotetraploid containing S T genomes inherited from sylvestris tomentosiformis progenitors. To determine inheritance methyltransferase their expression patterns examined three major families (MET1, CMT3 DRM) tobacco progenitor species. Using Southern blot PCR-based methods (genomic CAPS), found parental loci these gene are retained tobacco. Homoeologous was all tissues (leaf, root, flower) suggesting were probably not themselves targets uniparental silencing for over thousands generations evolution. level CG CHG selected high-copy repeated sequences similar high its diploid We speculate natural selection might favor additive maintaining levels tobacco, which has a repeat-rich heterochromatic genome.