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Ependymal cells of chordate larvae are stem-like cells that form the adult nervous system


In ascidian tunicates, the metamorphic transition from larva to adult is accompanied by dynamic changes in the body plan. For instance, the central nervous system (CNS) is subjected to extensive rearrangement because its regulating larval organs are lost and new adult organs are created1. To understand how the adult CNS is reconstructed, we traced the fate of larval CNS cells during ascidian metamorphosis by using transgenic animals and imaging technologies with photoconvertible fluorescent proteins2. Here we show that most parts of the ascidian larval CNS, except for the tail nerve cord, are maintained during metamorphosis and recruited to form the adult CNS. We also show that most of the larval neurons disappear and only a subset of cholinergic motor neurons and glutamatergic neurons are retained. Finally, we demonstrate that ependymal cells of the larval CNS contribute to the construction of the adult CNS and that some differentiate into neurons in the adult CNS. An unexpected role of ependymal cells highlighted by this study is that they serve as neural stem-like cells to reconstruct the adult nervous network during chordate metamorphosis. Consequently, the plasticity of non-neuronal ependymal cells and neuronal cells in chordates should be re-examined by future studies3,4.

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Figure 1: Tracing of cells in the larval CNS.
Figure 2: Tracing of larval cholinergic neurons and ependymal cells, and differentiation of larval ependymal cells to adult cholinergic neurons.
Figure 3: Adult CNS is constructed from the larval CNS.


  1. Nielsen, C. Larval and adult brains. Evol. Dev. 7, 483–489 (2005)

    Article  Google Scholar 

  2. Ando, R., Hama, H., Yamamoto-Hino, M., Mizuno, H. & Miyawaki, A. An optical marker based on the UV-induced green-to-red photoconversion of a fluorescent protein. Proc. Natl Acad. Sci. USA 99, 12651–12656 (2002)

    Article  ADS  CAS  Google Scholar 

  3. Barres, B. A. The mystery and magic of glia: a perspective on their roles in health and disease. Neuron 60, 430–440 (2008)

    Article  CAS  Google Scholar 

  4. Allen, N. J. & Barres, B. A. Glia – more than just brain glue. Nature 457, 675–677 (2009)

    Article  ADS  CAS  Google Scholar 

  5. Satoh, N. Developmental Biology of Ascidians (Cambridge University Press, 1994)

    Google Scholar 

  6. Wada, H., Saiga, H., Satoh, N. & Holland, P. W. Tripartite organization of the ancestral chordate brain and the antiquity of placodes: insight from ascidian Pax-2/5/8, Hox and Otx genes. Development 125, 1113–1122 (1998)

    CAS  PubMed  Google Scholar 

  7. Manni, L. et al. Neurogenic and non-neurogenic placodes in ascidians. J. Exp. Zool. B 302, 483–504 (2004)

    Article  Google Scholar 

  8. Manni, L., Agnoletto, A., Zaniolo, G. & Burighel, P. Stomodeal and neurohypophysial placodes in Ciona intestinalis: insights into the origin of the pituitary gland. J. Exp. Zool. B 304, 324–339 (2005)

    Article  Google Scholar 

  9. Dufour, H. D. et al. Precraniate origin of cranial motoneurons. Proc. Natl Acad. Sci. USA 103, 8727–8732 (2006)

    Article  ADS  CAS  Google Scholar 

  10. Kusakabe, T., Yoshida, R., Ikeda, Y. & Tsuda, M. Computational discovery of DNA motifs associated with cell type-specific gene expression in Ciona . Dev. Biol. 276, 563–580 (2004)

    Article  CAS  Google Scholar 

  11. Tarallo, R. & Sordino, P. Time course of programmed cell death in Ciona intestinalis in relation to mitotic activity and MAPK signaling. Dev. Dyn. 230, 251–262 (2004)

    Article  CAS  Google Scholar 

  12. Katz, M. J. Comparative anatomy of the tunicate tadpole Ciona intestinalis . Biol. Bull. 164, 1–27 (1983)

    Article  Google Scholar 

  13. Nicol, D. & Meinertzhagen, I. A. Cell counts and maps in the larval central nervous system of the ascidian Ciona intestinalis (L.). J. Comp. Neurol. 309, 415–429 (1991)

    Article  CAS  Google Scholar 

  14. Horie, T., Kusakabe, T. & Tsuda, M. Glutamatergic networks in the Ciona intestinalis larva. J. Comp. Neurol. 508, 249–263 (2008)

    Article  CAS  Google Scholar 

  15. Horie, T., Nakagawa, M., Sasakura, Y. & Kusakabe, T. G. Cell type and function of neurons in the ascidian nervous system. Dev. Growth Differ. 51, 207–220 (2009)

    Article  CAS  Google Scholar 

  16. Horie, T., Nakagawa, M., Sasakura, Y., Kusakabe, T. G. & Tsuda, M. Simple motor system of the ascidian larva: neuronal complex comprising putative cholinergic and GABAergic/glycinergic neurons. Zool. Sci. 27, 181–190 (2010)

    Article  CAS  Google Scholar 

  17. Takamura, K., Egawa, T., Ohnishi, S., Okada, T. & Fukuoka, T. Developmental expression of ascidian neurotransmitter synthesis genes. I. Choline acetyltransferase and acetylcholine transporter genes. Dev. Genes Evol. 212, 50–53 (2002)

    Article  CAS  Google Scholar 

  18. Yoshida, R. et al. Identification of neuron-specific promoters in Ciona intestinalis . Genesis 39, 130–140 (2004)

    Article  CAS  Google Scholar 

  19. Konno, A. et al. Distribution and structural diversity of cilia in tadpole larvae of the ascidian Ciona intestinalis . Dev. Biol. 337, 42–62 (2010)

    Article  CAS  Google Scholar 

  20. Tsuda, M. et al. Origin of the vertebrate visual cycle: II. Visual cycle proteins are localized in whole brain including photoreceptor cells of a primitive chordate. Vision Res. 43, 3045–3053 (2003)

    Article  CAS  Google Scholar 

  21. Moret, F. et al. Regulatory gene expressions in the ascidian ventral sensory vesicle: evolutionary relationships with the vertebrate hypothalamus. Dev. Biol. 277, 567–579 (2005)

    Article  CAS  Google Scholar 

  22. Imai, K. S., Stolfi, A., Levine, M. & Satou, Y. Gene regulatory networks underlying the compartmentalization of the Ciona central nervous system. Development 136, 285–293 (2009)

    Article  CAS  Google Scholar 

  23. Gilbert, S. F. Developmental Biology 8th edn (Sinauer Associates, 2006)

    Google Scholar 

  24. Johansson, C. F. et al. Identification of a neural stem cell in the adult mammalian central nervous system. Cell 96, 25–34 (1999)

    Article  CAS  Google Scholar 

  25. Coskun, V. et al. CD133+ neural stem cells in the ependyma of mammalian postnatal forebrain. Proc. Natl Acad. Sci. USA 105, 1026–1031 (2008)

    Article  ADS  CAS  Google Scholar 

  26. Chojnacki, A. K., Mak, G. K. & Weiss, S. Identity crisis for adult periventricular neural stem cells: subventricular zone astrocytes, ependymal cells or both? Nature Rev. Neurosci. 10, 153–163 (2009)

    Article  CAS  Google Scholar 

  27. Sasakura, Y., Awazu, S., Chiba, S. & Satoh, N. Germ-line transgenesis of the Tc1/mariner superfamily transposon Minos in Ciona intestinalis . Proc. Natl Acad. Sci. USA 100, 7726–7730 (2003)

    Article  ADS  CAS  Google Scholar 

  28. Joly, J. S. et al. Culture of Ciona intestinalis in closed systems. Dev. Dyn. 236, 1832–1840 (2007)

    Article  Google Scholar 

  29. Hozumi, A. et al. Efficient transposition of a single Minos transposon copy in the genome of the ascidian Ciona intestinalis with a transgenic line expressing transposase in the egg. Dev. Dyn. 239, 1076–1088 (2010)

    Article  CAS  Google Scholar 

  30. Matsuoka, T., Awazu, S., Shoguchi, E., Satoh, N. & Sasakura, Y. Germline transgenesis of the ascidian Ciona intestinalis by electroporation. Genesis 41, 67–72 (2005)

    Article  CAS  Google Scholar 

  31. Ikuta, T. & Saiga, H. Dynamic change in the expression of developmental genes in the ascidian central nervous system: revisit to the tripartite model and the origin of midbrain–hindbrain boundary region. Dev. Biol. 312, 631–643 (2007)

    Article  CAS  Google Scholar 

  32. Cole, A. G. & Meinertzhagen, I. A. The central nervous system of the ascidian larva: mitotic history of cells forming the neural tube in late embryonic Ciona intestinalis . Dev. Biol. 271, 239–262 (2004)

    Article  CAS  Google Scholar 

  33. Satou, Y., Imai, K. S. & Satoh, N. The ascidian Mesp gene specifies heart precursor cells. Development 131, 2533–2541 (2004)

    Article  CAS  Google Scholar 

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We acknowledge the members of the Shimoda Marine Research Center at the University of Tsukuba for their cooperation with our study. We also thank National Bio-resource Project, Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT), S. Fujiwara and all members of the Maizuru Fishery Research Station of Kyoto University and the Education and Research Center of Marine Bioresources of Tohoku University for providing us with Ciona adults, and C. Savakis for providing Minos. This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science and MEXT to T.H., T.G.K., N.S. and Y.S. Y.S. was supported by the National Institute of Genetics Cooperative Research Program.

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T.H. and Y.S. designed the experiments. T.H., R.S. and Y.O. performed most of the experiments. T.H. and T.G.K. isolated cis regulatory elements. T.G.K. and N.S. were advisors for the experiments and evaluated the data. T.H., N.S. and Y.S. wrote the manuscript.

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Correspondence to Takeo Horie.

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The authors declare no competing financial interests.

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Horie, T., Shinki, R., Ogura, Y. et al. Ependymal cells of chordate larvae are stem-like cells that form the adult nervous system. Nature 469, 525–528 (2011).

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