Spontaneous Fusion and Nonclonal Growth of Adult Neural Stem Cells
Article first published online: 21 DEC 2006
Copyright © 2007 AlphaMed Press
Volume 25, Issue 4, pages 871–874, April 2007
How to Cite
Jessberger, S., Clemenson, G. D. and Gage, F. H. (2007), Spontaneous Fusion and Nonclonal Growth of Adult Neural Stem Cells. STEM CELLS, 25: 871–874. doi: 10.1634/stemcells.2006-0620
- Issue published online: 2 JAN 2009
- Article first published online: 21 DEC 2006
- Manuscript Accepted: 13 DEC 2006
- Manuscript Received: 2 OCT 2006
- Adult neural stem cell;
- Nonclonal growth
Multipotent neural stem cells (NSCs) can be isolated from various regions of the adult brain and propagated in vitro. Recent reports have suggested spontaneous fusion events among NSCs when grown as free-floating neurospheres that may affect the genetic composition of NSC cultures. We used adult NSCs expressing either red fluorescent protein (RFP) or green fluorescent protein (GFP) to analyze the fusion frequency of rat and mouse NSCs. Fluorescence-activated cell sorting (FACS) revealed that, under proliferating conditions, approximately 0.2% of rat and mouse NSCs coexpressed RFP and GFP irrespective of whether the cells were grown as neurospheres (mouse NSCs) or as attached monolayers (rat and mouse NSCs). Fused cells did not proliferate and could not be propagated, suggesting that aberrantly fused cells are not viable. Furthermore, we found that neither neurospheres nor monolayers grew clonally, because even very low-density cultures had spheres containing both GFP- and RFP-expressing cells and monolayer patches with GFP- and RFP-expressing cells in close proximity. The nonclonal growth between distinct NSC populations strongly suggests the use of careful and precise culture conditions, such as single-cell assays, to characterize potency and growth of NSCs in vitro.
Disclosure of potential conflicts of interest is found at the end of this article.