EXPRESSION OF RETINOID-X RECEPTORS IN P19 EMBRYONAL CARCINOMA-CELLS AND EMBRYONIC STEM-CELLS

The pluripotent mouse embryonal carcinoma cell line P19 provides an ex cellent model system to study the mechanisms by which retinoic acid (R A) exerts its biological effects. When aggregated and exposed to low c oncentrations of RA, P19 cells differentiate into neuron- and glial-li ke cells. The diverse biological effects of RA are mediated by two fam ilies of receptors localized in the cell nucleus, the retinoic acid re ceptors (RARs) and the retinoid X receptors (RXRs). family consists of three members designated alpha, beta and gamma. patterns of expressio n of the RARs have been studied in P19 cells, similar data for the RXR s have not been available. We demonstrate here that these receptors ar e expressed in P19 and are regulated during RA-induced differentiation . We also show that pluripotent mouse embryonic stem cells express the RXRs as well. (C) 1994 Academic Press, Inc.