Pitx2 determines left–right asymmetry of internal organs in vertebrates

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The handedness of visceral organs is conserved among vertebrates and is regulated by asymmetric signals relayed by molecules such as Shh, Nodal and activin. The gene Pitx2 is expressed in the left lateral plate mesoderm and, subsequently, in the left heart and gut of mouse, chick and Xenopus embryos. Misexpression of Shh and Nodal induces Pitx2 expression, whereas inhibition of activin signalling blocks it. Misexpression of Pitx2 alters the relative position of organs and the direction of body rotation in chick and Xenopus embryos. Changes in Pitx2 expression are evident in mouse mutants with laterality defects. Thus, Pitx2 seems to serve as a critical downstream transcription target that mediates left–right asymmetry in vertebrates.

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Figure 1: Pitx2 is expressed asymmetrically in the lateral plate mesoderm, heart and gut.
Figure 4: Expression of Pitx2 is altered in iv and inv mice.
Figure 2: Pitx2 is downstream of Sonic hedgehog and Nodal.
Figure 3: Ectopic expression of Pitx2 affects left–right asymmetry of the heart and the gut.
Figure 5: ActRII-ECD binds activin.
Figure 6: A dominant negative activin receptor alters expression of nodal and Pitx2 and causes reversal of heart looping.


  1. 1

    Burn, J. Disturbance of morphological laterality in humans.In Biological Asymmetry and Handedness(eds Bock, G. R. & Marsh, J.) 282–299 (Wiley, New York, (1991)).

  2. 2

    Kosaki, K. & Casey, B. Genetics of human left–right axis of malformations. Sem. Cell Dev. Biol. 9, 89–99 (1998).

  3. 3

    Supp., D. M. Bruickner, M. & Potter, S. S. Handed assymetry in the mouse: Understanding how things go right (or left) by studying how they go wrong. Sem. Cell Dev. Biol. 9, 77–87 (1998).

  4. 4

    Splitt, M. P., Burn, J. & Goodship, J. Defects in the determination of left–right asymmetry. J. Med. Genet. 33, 498–503 (1996).

  5. 5

    Wood, W. B. Left–right asymmetry in animal development. Annu. Rev. Cell Dev. Biol. 13, 53–82 (1997).

  6. 6

    Lander, A., King, T. & Brown, N. A. Left–right development: Mammalian phenotypes and conceptual models. Sem. Cell Dev. Biol. 9, 35–41 (1998).

  7. 7

    Levin, M. & Mercola, M. The compulsion of chirality: towards understanding of left–right asymmetry. Genes Dev. 12, 763–769 (1998).

  8. 8

    Levin, M., Johnson, R. L., Stern, C. D., Kuehn, M. & Tabin, C. Amolecular pathway determining left–right asymmetry in chick embryogenesis. Cell 82, 803–814 (1995).

  9. 9

    Levin, M. et al. Left/right patterning signals and the independent regulation different aspects of situs in the chick embryo. Dev. Biol. 189, 57–67 (1997).

  10. 10

    Stern, C. D. et al. Activin and its receptors during gastrulation and the later phases of mesoderm development in the chick embryo. Dev. Biol. 172, 192–205 (1995).

  11. 11

    Hyatt, B. A., Lohr, J. L. & Yost, H. J. Initiation of vertebrate left–right axis formation by maternal Vg1. Nature 384, 62–65 (1996).

  12. 12

    Hyatt, B. A. & Yost, H. J. The left–right coordinator: the role of Vg1 in organizing left–right axis formation. Cell 93, 37–46 (1998).

  13. 13

    Matzuk, M. M., Kumar, T. R. & Bradley, A. Different phenotypes for mice deficient in either activins or activin receptor type II. Nature 374, 356–360 (1995).

  14. 14

    Chiang, C. et al. Cyclopia and defective axial patterning in mice lacking Sonic hedgehog gene function. Nature 383, 407–413 (1996).

  15. 15

    Matzuk, M. M. et al. Multiple defects and perinatal death in mice deficient in follistatin. Nature 374, 360–363 (1995).

  16. 16

    Matzuk, M. M. et al. Functional analysis of activins during mammalian development. Nature 374, 354–356 (1995).

  17. 17

    Vassalli, A., Matzuk, M. M., Gardner, H. A., Lee, K. F. & Jaenisch, R. Activin/inhibin βB subunit gene disruption leads to defects in eyelid development and female reproduction. Genes Dev. 8, 414–427 (1994).

  18. 18

    Oh, S. P. & Li, E. The signaling pathway mediated by the type IIB activin receptor controls axial patterning and lateral asymemtry in the mouse. Genes Dev. 11, 1812–1826 (1997).

  19. 19

    Collignon, J., Varlet, I. & Robertson, E. J. Relationship between asymmetric nodal expression and the direction of embryonic turning. Nature 381, 155–158 (1996).

  20. 20

    Lowe, L. A. et al. Conserved left–right asymmetry of nodal expression and alterations in murine situs inversus. Nature 381, 158–161 (1996).

  21. 21

    Supp, D. M. et al. Mutation of an axonemal dynein affects left-right asymmetry in inversus viscerum mice. Nature 389, 963–966 (1997).

  22. 22

    Heymer, J., Kuehn, M. & Rüther, U. The expression pattern of nodal and Lefty in the mouse mutant Ft suggests a function in the establishment of handedness. Mech. Dev. 66, 5–11 (1997).

  23. 23

    Melloy, P. G. et al. No turning, a mouse mutation causing left–right and axial patterning defects. Dev. Biol. 193, 77–89 (1998).

  24. 24

    Lohr, J. L., Danos, M. C. & Yost, J. H. Left-right asymmetry of a nodal-related gene is regulated by dorsoanterior midline structures during Xenopus develpment. Development 124, 1467–1472 (1997).

  25. 25

    Levin, M. Left-right asymmetry in vertebrate embryogenesis. Bioessays 19, 287–296 (1997).

  26. 26

    Pagán-Westphal, S. M. & Tabin, C. J. The transfer of left–right positional information during chick embryogenesis. Cell 93, 25–35 (1998).

  27. 27

    Isaac, A., Sargent, M. G. & Cooke, J. Control of vertebrate left–right asymmetry by a Snail-related zinc-finger gene. Science 275, 1301–1304 (1997).

  28. 28

    Srivastava, D., Cserjesi, P. & Olson, E. N. Asubclass of bHLH proteins required for cardiac morphogenesis. Science 270, 1995–1999 (1995).

  29. 29

    Biben, C. & Harvey, R. P. Homeodomain factor Nkx2-5 controls left/right asymmetric expression of bHLH gene eHAND during murine heart development. Genes Dev. 11, 1357–1369 (1997).

  30. 30

    Semina, E. V. et al. Cloning and characterization of a novel bicoid-related homeobox transcription factor gene, RIEG, involved in Rieger syndrome. Nature Genet. 14, 392–399 (1996).

  31. 31

    Gage, P. J. & Camper, S. A. Pituitary homeobox 2, a novel member of the bicoid-related family of homeobox genes, is a potential regulator of anterior structure formation. Hum. Mol. Genet. 6, 457–464 (1997).

  32. 32

    Muccielli, M. L., Martinez, S., Pattyn, A., Goridis, C. & Brunet, J. F. Otlx2, and Otx-related homeobox gene expressed in the pituitary gland and in a restricted pattern in the forebrain. Mol. Cell Neurosci. 8, 258–271 (1996).

  33. 33

    Hirofumi, A. et al. Identification and characterization of the ARP1 gene, a target for the human acute leukemia ALL1 gene. Proc. Natl Acad. Sci. USA 95, 4573–4578 (1998).

  34. 34

    Lamonerie, T. et al. Ptx1, a bicoid-related homeobox transcription factor involved in transcription of the pro-opiomelanocortin gene. Genes Dev. 10, 1284–1295 (1996).

  35. 35

    Szeto, D. P., Ryan, A. K., O'Connell, S. M. & Rosenfeld, M. G. P-OTX: A PIT-1 interaction homeodomain factor expressed during anterior pituitary gland development. Porc. Natl Acad. Sci. USA 93, 7706–7710 (1996).

  36. 36

    Lustig, K. D. et al. AXenopus nodal-related gene that acts in synergy with noggin to induce complete secondary axis and notochord formation. Development 122, 3275–3282 (1996).

  37. 37

    Logan, M., Pagán-Westphal, S., Smith, D., Paganesi, L. & Tabin, C. J. The transcription factor of Ptx-2 mediates situs-specific morphogenesis in response to left-right asymmetric signaling. Cell(in the press).

  38. 38

    Donalson, C. J., Vaughan, J. M., Corrigan, A. Z., Fischer, W. H. & Vale, W. W. Characterization of the soluble type II activin receptor extracellular domain. Biochemistry(submitted).

  39. 39

    New, D. A. T. Anew technique for the cultivation of the chick embryo in vitro. J. Embryol. Exp. Morphol. 3, 326–331 (1955).

  40. 40

    Sampath, K., Cheng, A. M. S., Frisch, A. & Wright, C. V. E. Functional differences among Xenopus nodal-related genes in left–right axis determination. Development 124, 3293–3302 (1997).

  41. 41

    Meno, C. et al. Two closely-related left-right asymmetrically expressed genes, lefty-1 and lefty-2: their distinct expression domains, chromosomal linkage and direct neuralizing activity in Xenopus embryos. Genes to Cells 2, 513–524 (1997).

  42. 42

    Meno, C. et al. Left-right asymmetric expression of the TGFβ-family member lefty in mouse embryos. Nature 381, 151–155 (1996).

  43. 43

    Meno, C. et al. Left-1 is required for left-right determination as a regulator of Lefty-2 and Nodal. Cell(in the press).

  44. 44

    Hamburger, V. & Hamilton, H. Aseries of normal stages in the development of the chick embryo. J. Morph. 88, 49–92 (1951).

  45. 45

    Wilkinson, D. G. in In Situ Hybridisation (ed. Wilkinson, D. G.) (Oxford University Press, Oxford, (1993)).

  46. 46

    Yonei, S., Tamura, K., Ohsugi, K. & Ide, H. MRC-5 cells induce the AER prior to the duplicated pattern formation in chick limb bud. Dev. Biol. 170, 542–552 (1995).

  47. 47

    Blumberg, B. et al. An essential role for retinoid signaling in anteroposterior neural patterning. Development 124, 373–379 (1997).

  48. 48

    Vogel, A., Rodriguez, C. & Izpisúa Belmonte, J. C. Involvement of FGF-8 in initiation, outgrowth and patterning of the vertebrate limb. Development 122, 1737–1750 (1996).

  49. 49

    Morgan, B. A., Izpisúa Belmonte, J. C., Duboule, D. & Tabin, C. J. Targeted misexpression of Hox-4.6 in the avian limb bud causes apparent homeotic transformations. Nature 358, 236–239 (1992).

  50. 50

    Cho, K. W. Y., Blumberg, B., Steinbeisser, H. & De Robertis, E. M. The role of the Xenopus homeobox gene goosecoid. Molecular nature of Spemann's organizer. Cell 67, 1111–1120 (1991).

  51. 51

    Blumberg, B. et al. BXR, an embryonic orphan nuclear receptor activated by a novel class of endogenous benzoate metabolites. Genes Dev. 12, 1269–1277 (1998).

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We thank E. Leonardo for her technical skills and dedication; F. H. Gage for access to the confocal laser scanning microscope; D. Peterson for assistance with confocal imaging; C. Tabin for sharing unpublished results; C. V. E. Wright, C. Tabin and L. Erkman and B. Eshelman for reagents and for discussion; J.Magallon and B. Eshelman for technical assistance; and L. Hooks and P. Myer for preparaing the manuscript. S.Y.T. and K.T. were supported by the J.S.P.S. M.G.R. and R.M.E. are investigators of the Howard Hughes Medical Institute; J.C.I.B. is a Pew Scholar. J.G is a HHMI predoctoral fellow. This work was supported by NIH grants to M.G.R., R.M.E. and J.C.I.B., by a G. Harold and Leila Y. Mathers Charitable Foundation grant to R.M.E., S.C., and J.C.I.B.

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Correspondence to Juan Carlos Izpisúa Belmonte.

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Ryan, A., Blumberg, B., Rodriguez-Esteban, C. et al. Pitx2 determines left–right asymmetry of internal organs in vertebrates. Nature 394, 545–551 (1998) doi:10.1038/29004

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