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From pre‐cells to Eukarya – a tale of two lipids
Author(s) -
Wächtershäuser G.
Publication year - 2003
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2003.03267.x
Subject(s) - archaea , biology , bacteria , population , membrane lipids , cell , microbiology and biotechnology , biochemistry , genetics , membrane , demography , sociology
Summary 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.