Mitsuyasu Hasebe: "Molecular mechanisms of cell-fate change from a differentiated cell to a stem cell in the moss Physcomitrella patens"

Mitsuyasu Hasebe
National Institute for Basic Biology, Okazaki, Japan
ERATO, JST, Okazaki, Japan
Graduate University for Advanced Studies, Okazaki, Japan

Molecular mechanisms of cell-fate change from a differentiated cell to a stem cell in the moss Physcomitrella patens

Differentiated cells can be reprogrammed to be pluripotent stem cells that are an undifferentiated type of cells with abilities for both self-renewing and giving rise to most cell types in the organism. An induction of reprogramming is more easily manipulated in plants than in animals, although genetic and molecular bases of the difference are mostly unexplored. The moss Physcomitrella patens has a high ability of reprogramming. Cells in a dissected leaf segment can be reprogrammed in water without any exogenous chemicals within 24 hours. We found that the reprogramming is induced by wounding and light signaling, which is mediated by SQUAMOSA promoter binding proteins, bZIP and WOX transcription factors, AP2/ERF domain proteins, cold shock-domain proteins, and auxin signaling pathways. Dynamic changes of small RNA population and chromatin modification are also involved in the process. Spatial pattern of the reprogramming in the dissected leaf is regulated by an unknown inhibitory factor initiated from leaf cells under reprogramming. I will discuss on their regulatory networks and the connection to cell cycle regulators.