Editors' ChoiceDevelopment

Developmental Balancing Act

STKE  26 Apr 2005:
Vol. 2005, Issue 281, pp. tw160
DOI: 10.1126/stke.2812005tw160

In vertebrates, somites are the developmental precursors for muscle and bone. Several signaling pathways affect somite development, and elimination of the retinoic acid (RA)-synthesizing enzyme RALDH2 yields compacted somites. Vermot et al. examined how the RA contributes to the control of somite development. When RALDH2 was eliminated in mice, the coordinated left-right symmetry in somite development was affected in somite stages 8 to 15, with as many as three extra somites observed on one side relative to the other. An apparent correction in this asymmetry occurs later in development. Embryonic RA appears to coordinate the progression of somite-specific signaling and development along the left and right sides of the organism.

J. Vermot, J. G. Llamas, V. Fraulob, K. Niederreither, P. Chambon, P. Dollé, Retinoic acid controls the bilateral symmetry of somite formation in the mouse embryo. Science 308, 563-566 (2005). [Abstract] [Full Text]