How does a stem cell decide what specialized identity to adopt – or simply to remain a stem cell? A new study suggests that the conventional view, which assumes that cells are “instructed” to progress along prescribed signaling pathways, is too simplistic. Instead, it supports the idea that cells differentiate through the collective behavior of multiple genes in a network that ultimately leads to just a few endpoints – just as a marble on a hilltop can travel a nearly infinite number of downward paths, only to arrive in the same valley.
The findings, published in the May 22 issue of Nature, give a glimpse into how that collective behavior works, and show that cell populations maintain a built-in variability that nature can harness for change under the right conditions. The findings also help explain why the process of differentiating stem cells into specific lineages in the laboratory has been highly inefficient.
Led by Sui Huang, MD, PhD, a Visiting Associate Professor in the Children’s Hospital Boston Vascular Biology Program (now also on the faculty of the University of Calgary), and Hannah Chang, an MD/PhD student in Children’s Vascular Biology Program, the researchers examined how blood stem cells “decide” to become white blood cell progenitors or red blood cell progenitors.
