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Chiral blastomere arrangement dictates zygotic left–right asymmetry pathway in snails


Most animals display internal and/or external left–right asymmetry. Several mechanisms for left–right asymmetry determination have been proposed for vertebrates1,2,3,4,5,6,7,8,9,10 and invertebrates1,2,4,9,11,12,13,14 but they are still not well characterized, particularly at the early developmental stage. The gastropods Lymnaea stagnalis and the closely related Lymnaea peregra have both the sinistral (recessive) and the dextral (dominant) snails within a species and the chirality is hereditary, determined by a single locus that functions maternally15,16,17,18. Intriguingly, the handedness-determining gene(s) and the mechanisms are not yet identified. Here we show that in L. stagnalis, the chiral blastomere arrangement at the eight-cell stage (but not the two- or four-cell stage) determines the left–right asymmetry throughout the developmental programme, and acts upstream of the Nodal signalling pathway. Thus, we could demonstrate that mechanical micromanipulation of the third cleavage chirality (from the four- to the eight-cell stage) leads to reversal of embryonic handedness. These manipulated embryos grew to ‘dextralized’ sinistral and ‘sinistralized’ dextral snails—that is, normal healthy fertile organisms with all the usual left–right asymmetries reversed to that encoded by the mothers’ genetic information. Moreover, manipulation reversed the embryonic nodal expression patterns. Using backcrossed F7 congenic animals, we could demonstrate a strong genetic linkage between the handedness-determining gene(s) and the chiral cytoskeletal dynamics at the third cleavage that promotes the dominant-type blastomere arrangement. These results establish the crucial importance of the maternally determined blastomere arrangement at the eight-cell stage in dictating zygotic signalling pathways in the organismal chiromorphogenesis. Similar chiral blastomere configuration mechanisms may also operate upstream of the Nodal pathway in left–right patterning of deuterostomes/vertebrates.

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Figure 1: Reversal of the third cleavage directions by micromanipulation and the resultant 8-, 12- and 16-cell stage embryos.
Figure 2: Chirality-reversed eight-cell stage embryos developed to snails with an oppositely-coiled shell and visceral situs inversus.
Figure 3: nodal and Pitx expression in control, congenic F 7 progeny, and chirality-inverted L. stagnalis embryos.
Figure 4: Determinants of chirality in the snail L. stagnalis.

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Data deposits

Sequences of L. stagnalis nodal and Pitx are deposited at GenBank, with accession numbers respectively GU073383 and GU073384.


  1. Brown, N. A. & Wolpert, L. The development of handedness in left/right asymmetry. Development 109, 1–9 (1990)

    CAS  PubMed  Google Scholar 

  2. Spéder, P., Petzoldt, A., Suzanne, M. & Noselli, S. Strategies to establish left/right asymmetry in vertebrates and invertebrates. Curr. Opin. Genet. Dev. 17, 351–358 (2007)

    Article  Google Scholar 

  3. Shiratori, H. & Hamada, H. The left-right axis in the mouse: from origin to morphology. Development 133, 2095–2104 (2006)

    Article  CAS  Google Scholar 

  4. Vandenberg, L. N. & Levin, M. Perspectives and open problems in the early phases of left-right patterning. Semin. Cell Dev. Biol. 20, 456–463 (2009)

    Article  Google Scholar 

  5. Nonaka, S., Shiratori, H., Saijoh, Y. & Hamada, H. Determination of left-right patterning of the mouse embryo by artificial nodal flow. Nature 418, 96–99 (2002)

    Article  ADS  CAS  Google Scholar 

  6. Okada, Y., Takeda, S., Tanaka, Y., Belmonte, J. C. & Hirokawa, N. Mechanism of nodal flow: a conserved symmetry breaking event in left-right axis determination. Cell 121, 633–644 (2005)

    Article  CAS  Google Scholar 

  7. Nonaka, S. et al. De novo formation of left-right asymmetry by posterior tilt of nodal cilia. PLoS Biol. 3, e268 (2005)

    Article  Google Scholar 

  8. Hirokawa, N., Tanaka, Y., Okada, Y. & Takeda, S. Nodal flow and the generation of left-right asymmetry. Cell 125, 33–45 (2006)

    Article  CAS  Google Scholar 

  9. Levin, M. & Palmer, A. R. Left-right patterning from the inside out: widespread evidence for intracellular control. Bioessays 29, 271–287 (2007)

    Article  CAS  Google Scholar 

  10. Levin, M., Thorlin, T., Robinson, K. R., Nogi, T. & Mercola, M. Asymmetries in H+/K+-ATPase and cell membrane potentials comprise a very early step in left-right patterning. Cell 111, 77–89 (2002)

    Article  CAS  Google Scholar 

  11. Spéder, P., Ádám, G. & Noselli, S. Type ID unconventional myosin controls left-right asymmetry in Drosophila . Nature 440, 803–807 (2006)

    Article  ADS  Google Scholar 

  12. Hozumi, S. et al. An unconventional myosin in Drosophila reverses the default handedness in visceral organs. Nature 440, 798–802 (2006)

    Article  ADS  CAS  Google Scholar 

  13. Wood, W. B. Evidence from reversal of handedness in C. elegans embryos for early cell interactions determining cell fates. Nature 349, 536–538 (1991)

    Article  ADS  CAS  Google Scholar 

  14. Bergmann, D. C. et al. Embryonic handedness choice in C. elegans involves the Gα protein GPA-16. Development 130, 5731–5740 (2003)

    Article  CAS  Google Scholar 

  15. Boycott, A. E., Diver, C., Garstang, S. L., Hardy, A. C. & Turner, F. M. The inheritance of sinistrality in Lymnaea peregra . Phil. Trans. R. Soc. Lond. B 219, 51–131 (1930)

    Article  ADS  Google Scholar 

  16. Sturtevant, A. H. Inheritance of direction of coiling in Lymnaea . Science 58, 269–270 (1923)

    Article  ADS  CAS  Google Scholar 

  17. Freeman, G. & Lundelius, J. W. The developmental genetics of dextrality and sinistrality in the gastropod Lymnaea peregra . Wilhelm Roux Arch. Dev. Biol. 191, 69–83 (1982)

    Article  Google Scholar 

  18. Hosoiri, Y., Harada, Y. & Kuroda, R. Construction of a backcross progeny collection of dextral and sinistral individuals of a freshwater gastropod, Lymnaea stagnalis . Dev. Genes Evol. 213, 193–198 (2003)

    CAS  PubMed  Google Scholar 

  19. Crampton, H. E. Reversal of cleavage in a sinistral gastropod. Ann. NY Acad. Sci. 8, 167–170 (1894)

    Article  ADS  Google Scholar 

  20. Shibazaki, Y., Shimizu, M. & Kuroda, R. Body handedness is directed by genetically determined cytoskeletal dynamics in the early embryo. Curr. Biol. 14, 1462–1467 (2004)

    Article  CAS  Google Scholar 

  21. Meshcheryakov, V. N. & Beloussov, L. V. Asymmetrical rotations of blastomeres in early cleavage of gastropoda. Wilhelm Roux Arch. Dev. Biol. 177, 193–203 (1975)

    Article  CAS  Google Scholar 

  22. Wandelt, J. & Nagy, L. M. Left-right asymmetry: more than one way to coil a shell. Curr. Biol. 14, R654–R656 (2004)

    Article  CAS  Google Scholar 

  23. Freeman, G. & Lundelius, J. W. Evolutionary implications of the mode of D quadrant specification in coelomates with spiral cleavage. J. Evol. Biol. 5, 205–247 (2002)

    Article  Google Scholar 

  24. Duboc, V. & Lepage, T. A conserved role for the nodal signaling pathway in the establishment of dorso-ventral and left-right axes in deuterostomes. J. Exp. Zool. B 310, 41–53 (2008)

    Article  Google Scholar 

  25. Grande, C. & Patel, N. H. Nodal signalling is involved in left-right asymmetry in snails. Nature 457, 1007–1011 (2009)

    Article  ADS  CAS  Google Scholar 

  26. Nederbragt, A. J., van Loon, A. E. & Dictus, W. J. Expression of Patella vulgata orthologs of engrailed and dpp-BMP2/4 in adjacent domains during molluscan shell development suggests a conserved compartment boundary mechanism. Dev. Biol. 246, 341–355 (2002)

    Article  CAS  Google Scholar 

  27. Christiaen, L. et al. Pitx genes in Tunicates provide new molecular insight into the evolutionary origin of pituitary. Gene 287, 107–113 (2002)

    Article  CAS  Google Scholar 

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We thank G. Smit for his gift of dextral and sinistral stock of L. stagnalis. We also thank K. Miyoshi, Y. Ozawa and H. Kuwata of the Kuroda Chiromorphology team for their help in rearing snails and creating F7 congenic snails. K. Fujikura, A. Okubo and G. Sai are thanked for their preliminary attempts at in situ hybridization experiments.

Author Contributions R.K. conceived the study, designed/coordinated the experiments and wrote the manuscript. B.E. performed the reversal experiments and whole mount in situ hybridization (WISH) on reversed embryos. M.A. performed WISH on control and F7 congenic snails. M.S. cloned and characterized nodal and Pitx from L. stagnalis to make template vector for the WISH probes. B.E. and M.S. provided comments on the manuscript.

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Correspondence to Reiko Kuroda.

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Kuroda, R., Endo, B., Abe, M. et al. Chiral blastomere arrangement dictates zygotic left–right asymmetry pathway in snails . Nature 462, 790–794 (2009).

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