Pluripotent Model Organisms

Abstract

Embryonic stem cells were not the first cultured stem cells. That distinction belongs to ‘embryonal carcinoma cells,’ first derived in the 1960s from mouse cancer cells. Approximately a decade later, embryonic stem cells were derived from mice. But it was nearly 20 years before a similar method was successfully applied to humans. Human embryonic stem cells (hESC) are a recent innovation. Today they symbolize the hopes of regenerative medicine, spurring reorganization of biomedical resources and reformulation of research goals to encourage new forms of collaboration, new technologies, and new ways of engaging in politics.¹³⁶ In this chapter, I argue that their role is best characterized as that of a model organism, selected and modified to serve as an exemplar for biological research. I show how hESC were originally constructed out of earlier model systems, tracing this line of research back to studies of cancer in the 1950s. Over five decades, a network of models was constructed via complex comparative relations among pluripotent cell lines. The origins and structure of this ‘pluripotency network’ shed light on both the organization of stem cell research today and the significance of hESC in these biomedical inquiries.