Research Interests

My aim is to understand how a cell maintains or changes identity and to understand what limits the repertoire of identities that a particular cell can become. I use human embryonic (ES) stem cells as a model system because their unlimited proliferative capacity and developmental potential make them uniquely suited for exploring these themes in human material. In the early 1990s my laboratory derived ES cells from the macaque and marmoset, work that led to the derivation of human ES cells. Much of the initial work in my laboratory after that derivation was establishing human ES cells as an accepted, practical model system, and we developed improved culture conditions, methods for genetic manipulation, and approaches for the in vitro differentiation to key lineages of clinical importance. With human ES cells now firmly established as a practical model system, we are currently focused on using these tools to understand the basic biology of pluripotency. We use several conditions that induce uniform differentiation to specific lineages to study in detail how ES cells decide to exit the pluripotent state and become restricted in their potential, and study methods for reprogramming differentiated cells back to a pluripotent state.

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Primary Section

Section 61: Animal, Nutritional, and Applied Microbial Sciences

Secondary Section

Section 22: Cellular and Developmental Biology