Terminally differentiated cells are generally considered to be in a developmentally locked state in vivo; they are incapable of being directly reprogrammed into an entirely different state. Now, on , Joel Rothman and co-workers show that the expression of a single transcription factor can trigger the transdifferentiation of fully differentiated, highly specialised cells in C. elegans larvae and adults. They show that brief ectopic expression of ELT-7, a GATA transcription factor that regulates intestinal differentiation, can specifically convert non-endodermal cells of the pharynx into fully differentiated intestinal cells. This conversion is accompanied by an increase in the expression of intestine-specific genes and a concomitant decrease in the expression of pharynx-specific markers and structural proteins. The reprogrammed cells also exhibit morphological characteristics of intestinal cells. These, together with other findings in the study, demonstrate that terminally differentiated cells can be reprogrammed to an alternative fate without the need for cell division, without the requirement for a dedifferentiated intermediate state and without prior removal of an inhibitory factor.
