Do the different parental 'heteromes' cause genomic shock in newly formed allopolyploids?

Philos Trans R Soc Lond B Biol Sci. 2003 Jun 29;358(1434):1149-55. doi: 10.1098/rstb.2003.1305.


Allopolyploidy, the joining of two parental genomes in a polyploid organism with diploid meiosis, is an important mechanism of reticulate evolution. While many successful long-established allopolyploids are known, those formed recently undergo an instability phase whose basis is now being characterized. We describe observations made with the Arabidopsis system that include phenotypic instability, gene silencing and activation, and methylation changes. We present a model based on the epigenetic destabilization of genomic repeats, which in the parents are heterochromatinized and suppressed. We hypothesize that loss of epigenetic suppression of these sequences, here defined as the heterome, results in genomic instability including silencing of single-copy genes.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / genetics*
  • DNA Methylation
  • Gene Expression Regulation, Plant*
  • Gene Silencing*
  • Genes, Plant / genetics
  • Genome, Plant*
  • Heterochromatin / genetics*
  • Models, Genetic
  • Phenotype
  • Polyploidy*


  • Heterochromatin