REGULATED EXPRESSION OF BRACHYURY(T), NKX1.1 AND PAX GENES IN EMBRYOID BODIES

Embryonic stem cells (ES) can be exploited to analyze in vitro mechani sms of cellular differentiation. We have utilized ES-derived embryoid body formation in an attempt to study cell types resulting from in vit ro differentiation. To this end, a variety of molecular markers, prefe rably those which have been associated with regulatory events during m ouse embryogenesis, was employed. Specifically, Brachyury (T), Pax-3 a nd Pax-6 genes as well as Nkx-1.1 were used. We could demonstrate that the expression of these genes in vitro was regulated by growth factor s such as activin A or bFGF. Implications of these findings and the po ssible applications for identifying new genes are discussed. (C) 1994 Academic Press, Inc.