Cloning and expression pattern of EPAS1 in the chicken embryo - Colocalization with tyrosine hydroxylase

EPAS1 is a hypoxia-inducible transcription factor, highly expressed in vasc ulature and recently shown to be necessary for catecholamine production dur ing embryogenesis. We report here the cloning and detailed expression patte rn of this factor in the chicken embryo, We show that chicken EPAS1 present s an overall identity of 76% with the human sequence and that it is strongl y expressed in the blood vessel wall, mostly in endothelial cells, but also in vascular smooth muscle cells. Moreover, we report non-vascular expressi on sites: liver, kidney and, quite interestingly, cells of the sympathetic nervous system where EPAS1 is coexpressed with one of its putative target g enes, the tyrosine hydroxylase, EPAS1 could therefore represent the link be tween the vascular system sympathetic nervous system, both sensitive to hyp oxia. (C) 1999 Federation of European Biochemical Societies.