The high regenerative power of planarian has fascinated scientists for a long time. Although many famous scientists, including Thomas Hunt Morgan, extensively devoted themselves to studying mechanisms underlying regeneration, the planarian regeneration still remains mysterious phenomenon. Recently, modern approaches have been developed and incorporated in planarian research, and several mysterious points were clarified. Here, I focus on old problems of planarian stem cells. Planarian stem cells were called “neoblasts” and considered to be the only cells maintaining proliferative activity and pluripotency. However, recent analyses using molecular markers and FACS sorting revealed their heterogeneity. Now we should change the old view of the planarian stem cell system to one closer to mammalian stem cell systems. These insights indicate the planarian regeneration studies may provide new ideas for handling mouse and human ES cells for therapeutic use in the near future.
Keywordsplanarian regeneration neoblast stem cell pluripotent totipotent FACS
Unable to display preview. Download preview PDF.
- Baguñà, J., Saló, E., Auladell, C. 1989. Regeneration and pattern formation in planarians. III. Evidence that neoblasts are totipotent stem cells and the source of blastema cells. Development 107: 77–86.Google Scholar
- Baguñà, J., Romero, R., Saló, E., Collet, J., Auladell, C., Ribas, M., Riutort, M., García-Fernàndez, J., Burgaya, F., Bueno, D. 1990. Growth, degrowth and regeneration as developmental phenomena in adult freshwater planarians. Experimental Embryology in Aquatic Plants and Animals. pp. 129–162. Plenum Press, New York.Google Scholar
- Dubois, F. 1949. Contribution a l’etude de la regeneration chez planaires dulcicoles. Bull. Biol. 83: 213–218.Google Scholar
- Hori, I. 1982. An ultrastructural study of the chromatoid body in planarian regenerative cells. J. Electron Microsc. 31: 63–72.Google Scholar
- Hori, I. 1992. Cytological approach to morphogenesis in the planarian blastema. 1. Cell behavior during blastema formation. J. Submicrosc. Cytol. Pathol. 24: 75–84.Google Scholar
- Koinuma, S., Umesono, Y., Watanabe, K., Agata, K. 2003. The expression of planarian brain factor homologs, DjFoxG and DjFoxD. Mech. Dev. 3: 21–27.Google Scholar
- National Institutes of Health. 2001. Stem Cells: Scientific Progress and Future Directions. Retrieved 08–05–2004 from http://stemcells.nih.gov/info/basics/.
- Randolph, H. 1897. Observations and experiments on regeneration in planarians. Arch. Entw. Mech. Org. 5: 352–372.Google Scholar
- Teshirogi, W. 1962. Dynamic morphological change and timetable during the regeneration of the turbellarian. Sci. Rep. Hirosaki Univ. 9: 21–48.Google Scholar
- Teshirogi, W., Ishida, S. (Eds.) 1987. Biology of Planarians–Foundation, Application & Experiment, Kyoritsu syuppan, Tokyo.Google Scholar
- Wetzel, B.K. 1961. Studies on the fine structure of regenerating Dugesia tigrina. Diss. Harvard Univ. Cambridge, Massachusetts.Google Scholar
- Wolff, E., Dubois, F. 1948. Sur la migration des cellules de régénération chez les planaires. Rev. Suisse. Zool. 55: 218–227.Google Scholar