From pre-cells to Eukarya--a tale of two lipids

Mol Microbiol. 2003 Jan;47(1):13-22. doi: 10.1046/j.1365-2958.2003.03267.x.


A mechanistic hypothesis for the origin of the three domains of life is proposed. A population of evolving pre-cells is suggested to have had a membrane of a racemate of chiral lipids that continuously underwent spontaneous symmetry breaking by spatial phase segregation into two enantiomerically enriched membrane domains. By frequent pre-cell fusions and fissions these membrane domains became partitioned between two pre-cell subpopulations having predominantly one lipid enantiomer or the other. The origin of the Bacteria and Archaea is explained by divergence of first a population of proto-bacteria and later a population of proto-archaea from the evolving pre-cells, each by the emergence of an enantio-selective lipid biosynthesis within the corresponding pre-cell subtype. The origin of the Eukarya is explained by symbiosis between a population of Bacteria and a subpopulation of pre-cells with a predominance of the bacteria-type lipid enantiomers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Archaea / genetics*
  • Archaea / physiology
  • Bacteria / genetics*
  • Bacterial Physiological Phenomena
  • Eukaryotic Cells / physiology*
  • Evolution, Molecular
  • Membrane Lipids / chemistry
  • Membrane Lipids / metabolism*
  • Symbiosis*


  • Membrane Lipids