Rotation of organizer tissue contributes to left-right asymmetry

Anat Rec (Hoboken). 2009 Apr;292(4):557-61. doi: 10.1002/ar.20872.


Current hypotheses regarding vertebrate left-right asymmetry patterns are based on the presumption that genetic regulatory networks specify sidedness via extracellular morphogens and/or ciliary activity. We show empirical time-lapse evidence for an asymmetric rotation of epiblastic nodal tissue in avian embryos. This rotation spans the interval when initial symmetric expression of Shh and Fgf8 becomes asymmetrical with respect to the midline.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Patterning / physiology*
  • Chick Embryo
  • Embryonic Development / physiology*
  • Fibroblast Growth Factor 8 / genetics
  • Fibroblast Growth Factor 8 / metabolism
  • Functional Laterality / physiology*
  • Gene Expression Regulation, Developmental / physiology*
  • Hedgehog Proteins / genetics
  • Hedgehog Proteins / metabolism
  • Microscopy, Video / methods*
  • Organizers, Embryonic / cytology
  • Organizers, Embryonic / embryology*
  • Rotation
  • Time Factors


  • Hedgehog Proteins
  • Fibroblast Growth Factor 8