Please don't politicize this thread with such poorly researched, argumentative garbage. The premise of that piece has pretty much been completely discredited, in time I suspect to meet the author's print deadline.
Nature. 2004 May 6;429(6987):41-6. Related Articles, Links
Comment in:
Nature. 2004 May 6;429(6987):30-1.
Adult pancreatic beta-cells are formed by self-duplication rather than stem-cell differentiation.
Dor Y, Brown J, Martinez OI, Melton DA.
Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, Harvard University, 7 Divinity Avenue, Cambridge, Massachusetts 02138, USA.
How tissues generate and maintain the correct number of cells is a fundamental problem in biology. In principle, tissue turnover can occur by the differentiation of stem cells, as is well documented for blood, skin and intestine, or by the duplication of existing differentiated cells. Recent work on adult stem cells has highlighted their potential contribution to organ maintenance and repair. However, the extent to which stem cells actually participate in these processes in vivo is not clear. Here we introduce a method for genetic lineage tracing to determine the contribution of stem cells to a tissue of interest. We focus on pancreatic beta-cells, whose postnatal origins remain controversial. Our analysis shows that pre-existing beta-cells, rather than pluripotent stem cells, are the major source of new beta-cells during adult life and after pancreatectomy in mice. These results suggest that terminally differentiated beta-cells retain a significant proliferative capacity in vivo and cast doubt on the idea that adult stem cells have a significant role in beta-cell replenishment.
PMID: 15129273 [PubMed - indexed for MEDLINE] |
