EXPRESSION OF NK-2 CLASS HOMEOBOX GENE NKX2-6 IN FOREGUT ENDODERM ANDHEART

NK-2 class homeobox genes are candidate patterning and lineage regulat ors in diverse organisms. We report here the embryonic expression patt ern of murine member, Nkx2-6. In keeping with its vertebrate relatives , Nkx2-6 was transcribed in ventrolateral embryonic structures. Expres sion was first detected at E8.0 in endodermal walls of the foregut poc ket, tissue destined to become pharyngeal floor. From E8.0-10.5, trans cripts were concentrated in pharyngeal pouches and juxtaposed arch ect oderm and mesoderm, as well as in more caudal gut segments. Expression was also seen at opposite poles of the developing heart: from E8-8.5 in posterior myocardial progenitors, then sinus venosa and dorsal peri cardium, and from E9.5 in outflow tract myocardium. (C) 1998 Elsevier Science Ireland Ltd.