MANY animals with overall bilateral symmetry also exhibit some left–right asymmetries with generally invariant handedness. Therefore, the left–right embryonic axis must have a consistent polarity, whose origins and subsequent effects on development are not understood (reviewed in ref. 1). Caenorhabditis elegans exhibits such left–right asymmetries at all developmental stages. The embryonic cell lineage is asymmetric as well: although the animal is generally bilaterally symmetric, many of its contralaterally analogous cells arise from different lineages on the two sides of the embryo2,3. I accomplished reversal of embryonic handedness by micromanipulation at the 6-cell stage, which resulted in mirror-image but otherwise normal development into healthy, fertile animals with all the usual left–right asymmetries reversed. This result demonstrates that in the 6-cell embryo the pair of anterior (AB) blastomeres on the right is equivalent to the pair on the left, and that the extensive differences in fates between lineally homologous derivatives of these cells on the two sides of the animal must be dictated by cell interactions, most of which are likely to occur early in embryogenesis.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Brown, N. A. & Wolpert, L. Development 109, 1–9 (1990).
Sulston, J. E. et al., Devl Biol. 100, 64–119 (1983).
Sulston, J. E. Cold Spring Harb. Symp. quant. Biol. 48, 443–452 (1983).
Sulston, J. E. & Horvitz, H. R. Devl Biol. 56, 110–156 (1977).
White, J. G. et al. Phil. Trans. R. Soc. 314, 1–340 (1986).
White, J. in The Nematode Caenorhabditis elegans (ed. Wood, W. B.) 81–122 (Cold Spring Harbor, Laboratory, New York,, 1988).
Priess, J. & Thomson, J. N. Cell 48, 241–250 (1987).
zur Strassen, O. Arch. EntwMech. Org. 3, 27–105 (1896).
Dünschen, F. Arch. EntwMech. Org. 115, 237–335 (1929).
Bonfig, R. Z. Wissensch. Zool. 124, 407–456 (1925).
Laufer, J. S., Bazzicalupo, P. & Wood, W. B. Cell 19, 569–577 (1980).
Cowan, A. E. & Mclntosh, J. R. Cell 41, 923–932 (1985).
Edgar, L. G. & McGhee, J. D. Cell 53, 589–599 (1988).
Schierenberg, E. Devl Biol. 122, 452–463 (1987).
Priess, J. R., Schnabel, H. & Schnabel, R. Cell 51, 601–611 (1987).
Yochem, J. & Greenwald, I. Cell 58, 553–563 (1989).
Sulston, J. & Hodgkin, J. in The Nematode Caenorhabditis elegans (ed. Wood, W. B.) 587–606 (Cold Spring Harbor Laboratory, New York, 1988).
Deppe, U. et al. Proc. natn. Acad. Sci. U.S.A. 75, 376–380 (1978).
About this article
Journal of Statistical Physics (2012)
Nature Reviews Neuroscience (2002)