An imprinted gene underlies postzygotic reproductive isolation in Arabidopsis thaliana

Dev Cell. 2013 Sep 16;26(5):525-35. doi: 10.1016/j.devcel.2013.08.006. Epub 2013 Sep 5.

Abstract

Postzygotic reproductive isolation in response to interploidy hybridizations is a well-known phenomenon in plants that forms a major path for sympatric speciation. A main determinant for the failure of interploidy hybridizations is the endosperm, a nutritious tissue supporting embryo growth, similar to the functional role of the placenta in mammals. Although it has been suggested that deregulated imprinted genes underpin dosage sensitivity of the endosperm, the molecular basis for this phenomenon remained unknown. In a genetic screen for suppressors of triploid seed abortion, we have identified the paternally expressed imprinted gene ADMETOS (ADM). Here, we present evidence that increased dosage of ADM causes triploid seed arrest. A large body of theoretical work predicted that deregulated imprinted genes establish the barrier to interploidy hybridization. Our study thus provides evidence strongly supporting this hypothesis and generates the molecular basis for our understanding of postzygotic hybridization barriers in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics*
  • Cell Cycle Proteins / genetics*
  • Endosperm / genetics
  • Gene Expression Regulation, Plant
  • Genetic Speciation*
  • Genome, Plant
  • Genomic Imprinting*
  • Hybridization, Genetic
  • Polyploidy
  • Reproductive Isolation*
  • Seeds / genetics
  • Seeds / growth & development
  • Zygote / cytology
  • Zygote / growth & development

Substances

  • AMETOS protein, Arabidopsis thaliana
  • Arabidopsis Proteins
  • Cell Cycle Proteins