Blood Stem Cell Dividing Asymetically (IMAGE) University of Pennsylvania Caption Researchers have long wondered what allows hematopoietic stem cells to persist for decades, when their progeny last for days, weeks or months before they need to be replaced. Now, a study from the University of Pennsylvania has uncovered one of the mechanisms that allow these stem cells to keep dividing in perpetuity. The researchers found that a form of the motor protein that allows muscles to contract helps these cells divide asymmetrically, so that one part remains a stem cell while the other becomes a daughter cell. Their findings could provide new insight into blood cancers, such as leukemia, and eventually lead to ways of growing transfusable blood cells in a lab. Here, a hematopoietic stem cell divides asymmetrically. The motor protein — myosin IIB -- is labeled green, and is concentrated on the side that will remain a stem cell. Credit University of Pennsylvania. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.