Using new genetic tools, Cornell researchers have found that some stem cells in mice behave dramatically different than in fruit flies, where most of the pioneering stem cell work has been conducted. The findings could have important implications for understanding how some cancers might be initiated, say the researchers.
…The prevailing evidence for fruit flies (Drosophila) shows that normal adult stem cells generate two daughter cells with different fates; one becomes another stem cell, and the other becomes a differentiated cell with a fixed number of cell divisions left in its life. This is called an “asymmetric fate decision” because the daughter cells do not have identical fates.
The new study, published online Aug. 6 in the journal Cell Stem Cell, indicates that dividing hair follicle stem cells in adult mice, on the other hand, can undergo symmetric fates — the daughter cells can both become either stem cells or differentiated cells.
The study is among the first to consider directly how dividing stem cells choose their fate in undamaged mouse tissues. The findings imply that certain previously held assumptions about stem cell behavior in mammals may not be applicable to stem cells in all organ systems…