Stem cell system in asexual and sexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelida)
Version of Record online: 20 DEC 2009
© 2009 The Authors. Journal compilation © 2009 Japanese Society of Developmental Biologists
Development, Growth & Differentiation
Special Issue: Comparative Aspects of Stem Cells
Volume 52, Issue 1, pages 43–55, January 2010
How to Cite
Yoshida-Noro, C. and Tochinai, S. (2010), Stem cell system in asexual and sexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelida). Development, Growth & Differentiation, 52: 43–55. doi: 10.1111/j.1440-169X.2009.01149.x
- Issue online: 11 JAN 2010
- Version of Record online: 20 DEC 2009
- Received 21 September 2009; revised 13 October 2009; accepted 13 October 2009.
- stem cell
Enchytraeus japonensis is a small oligochaete species that proliferates asexually via fragmentation and regeneration. As sexual reproduction can also be induced, it is a good model system for the study of both regenerative and germline stem cells. It has been shown by histological study that putative mesodermal stem cells called neoblasts, and dedifferentiated epidermal and endodermal cells are involved in blastema formation. Recently, we isolated three region-specific marker genes expressed in the digestive tract and showed by in situ hybridization that morphallactic as well as epimorphic regulation of the body patterning occurs during regeneration. We also cloned two vasa-related genes and analyzed their expression during development and in mature worms that undergo sexual reproduction. The results arising form these studies suggest that the origin and development of germline stem cells and neoblasts may be independent. Furthermore, we carried out functional analysis using RNA interference (RNAi) and showed that a novel gene termed grimp is required for mesodermal cell proliferation at the initial stages of regeneration. These findings indicate that the stem cell system in E. japonensis is regulated by both internal and external environmental factors.