Human bodies are so complex that even the most essential and well-studied systems are still discovering new surprises.
For example, research in mice has found that blood may have not just one but two varieties of cellular origins within mammalian bodies.
“Historically, people have believed that most of our blood comes from a very small number of cells that eventually become blood stem cells, also known as hematopoietic stem cells,” clarifies the Harvard University cell biologist Fernando Camargo, who is one of the researchers on the mouse study.
“We were surprised to find another group of progenitor cells that do not come from stem cells. They make most of the blood in fetal life until young adulthood, and then gradually start decreasing.” These cells are called embryonic multipotent progenitors (eMPPs).
Utilizing a newly developed genetic barcoding technique, Harvard university biomedical scientist Mr.Sachin Patel and colleagues successfully tracked the dividing cells to detect that hematopoietic stem cells and eMPPs originated from the same lining.
The researchers injected bits of easy-to-detect DNA sequences into a spot within the mouse cell’s genome that would be transferred onto all their cellular offspring.
This enabled them to track the origins of all their target cells, thereby disclosing the eMPPs divided into cells accountable for developing most of the lymphoid cells in mice. These eMPP cells occur to be the mothers of many immune blood cells, involving white blood cells.