Xenopus Eya1 demarcates all neurogenic placodes as well as migrating hypaxial muscle precursors

We cloned two isoforms of the Xenopus Eya1 orthologue. They show identical patterns of expression that closely resemble the previously described expre ssion of XSix1, but partly differ from the expression of Eya1 in other vert ebrates. XEya1 is expressed in the somites and hypaxial muscle precursors, but not in the pronephros. Moreover. all ectodermal placodes except the len s placode strongly express XEya1. At neural plate stages, ectodermal XEya1 expression starts in two domains, the anterior neural folds and a domain la teral to the neural folds. At tailbud stages, XEya1 expression continues in the adenohypophysis, all neurogenic placodes and placodally-derived struct ures including cranial ganglia, the otic vesicle and lateral line primordia . (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.