At the Stowers Institute for Medical Research Researchers have captured the one cell that is capable of regenerating an entire organism. For over a century, scientists have witnessed the effects of this cellular marvel, which enables creatures such as the planarian flatworm to perform death-defying feats like regrowing a severed head. But until recently, they lacked the tools necessary to target and track this cell, so they could watch it in action and discover its secrets.
By pioneering a technique that combines genomics, single-cell analysis, flow cytometry and imaging, scientists have isolated this amazing regenerative cell — a subtype of the long-studied adult pluripotent stem cell — before it performs its remarkable act. The findings, published in the June 14, 2018, issue of the journal Cell, will likely propel biological studies on highly regenerative organisms like planarians and also inform regenerative medicine efforts for other organisms like humans that have less regenerative capacity.
Alexandra Sánchez Alvarado, Ph.D., an investigator at the Stowers Institute and Howard Hughes Medical Institute and senior author of the studies says, “the first time that an adult pluripotent stem cell has been isolated prospectively.”
“Our finding essentially says that this is no longer an abstraction, that there truly is a cellular entity that can restore regenerative capacities to animals that have lost it and that such entity can now be purified alive and studied in detail.”
Every multicellular organism is built from a single cell, which divides into two identical cells, then four, and so on. Each of these cells contains the exact same twisted strands of DNA, and is considered pluripotent — meaning it can give rise to all possible cell types in the body. But somewhere along the way, those starter cells — known as embryonic stem cells — resign themselves to a different fate and become skin cells, heart cells, muscle cells, or another cell type. In humans, no known pluripotent stem cells remain after birth. In planarians, they stick around into adulthood, where they become known as adult pluripotent stem cells or neoblasts. Scientists believe these neoblasts hold the secret to regeneration.