Retinoic acid coordinates somitogenesis and left-right patterning in vertebrate embryos

Nature. 2005 May 12;435(7039):215-20. doi: 10.1038/nature03488.


A striking feature of the body plan of a majority of animals is bilateral symmetry. Almost nothing is known about the mechanisms controlling the symmetrical arrangement of the left and right body sides during development. Here we report that blocking the production of retinoic acid (RA) in chicken embryos leads to a desynchronization of somite formation between the two embryonic sides, demonstrated by a shortened left segmented region. This defect is linked to a loss of coordination of the segmentation clock oscillations. The lateralization of this defect led us to investigate the relation between somitogenesis and the left-right asymmetry machinery in RA-deficient embryos. Reversal of the situs in chick or mouse embryos lacking RA results in a reversal of the somitogenesis laterality defect. Our data indicate that RA is important in buffering the lateralizing influence of the left-right machinery, thus permitting synchronization of the development of the two embryonic sides.

Publication types

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

MeSH terms

  • Aldehyde Oxidoreductases / deficiency
  • Aldehyde Oxidoreductases / genetics
  • Animals
  • Avian Proteins
  • Biomarkers / metabolism
  • Body Patterning / drug effects
  • Body Patterning / physiology*
  • Chick Embryo
  • Disulfiram / pharmacology
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / drug effects
  • Embryo, Mammalian / embryology*
  • Embryo, Mammalian / metabolism
  • Fibroblast Growth Factor 8
  • Fibroblast Growth Factors / genetics
  • Fibroblast Growth Factors / metabolism
  • Gene Expression Regulation, Developmental
  • Glycosyltransferases / genetics
  • Glycosyltransferases / metabolism
  • Hedgehog Proteins
  • Mice
  • Signal Transduction
  • Somites / cytology*
  • Somites / drug effects
  • Somites / metabolism*
  • Trans-Activators / metabolism
  • Tretinoin / metabolism*


  • Avian Proteins
  • Biomarkers
  • Fgf8 protein, mouse
  • Hedgehog Proteins
  • Trans-Activators
  • Fibroblast Growth Factor 8
  • Tretinoin
  • Fibroblast Growth Factors
  • Aldehyde Oxidoreductases
  • RALDH2 protein, mouse
  • Glycosyltransferases
  • LFNG protein, Gallus gallus
  • Lfng protein, mouse
  • Disulfiram