Planarians (Schmidtea mediterranea) are tiny freshwater flatworms with the ability to reproduce through fission. After literally tearing themselves in half, the worms use stem cells, called cNeoblasts, to regrow any missing tissues and organs, ultimately forming two complete planarians in about a week.
Unlike muscle, nerve, or skin cells that are fully differentiated, certain stem cells, such as cNeoblasts and embryonic stem cells are pluripotent, having the ability to become almost cell type in the body. Researchers have long been interested in harnessing this capability to regrow damaged, diseased, or missing tissues in humans, such as insulin-producing cells for diabetics or nerve cells for patients with spinal cord injuries.
Several problems currently confound the therapeutic use of stem cells, including getting the stem cells to differentiate into the desired cell type in the appropriate location and having such cells successfully integrate with surrounding tissues, all without forming tumors. To solve these issues, researchers need a better understanding of how stem cells tick at the molecular level, particularly within the environment of a living organism. To date, a considerable amount of embryonic stem cell research has been conducted in the highly artificial environment of the Petri dish.
With its renowned powers of regeneration and more than half of its genes having human homologs, the planarian seems like a logical choice for this line of research. Yet, until now, scientists have been unable to efficiently find the genes that regulate the planarian stem cell system.
Postdoctoral researcher Dan Wagner, first author of the Cell Stem Cell paper, and Reddien devised a clever method to identify potential genetic regulators and then determine if those genes affect the two main functions of stem
|Contact: Nicole Giese Rura|
Whitehead Institute for Biomedical Research