Fig. 4

The N-terminus of Eaf1 or Eaf2 acts as a dominant negative. (A) (a-f) Representative morphology of embryos injected with GFP mRNA or mRNA encoding the N-terminus of Eaf1 or Eaf2 (exons 1-3) at 26 or 50 hpf. (g) Embryos were scored morphologically at 50 hpf: white, the percentage of normal embryos; gray, embryos without forebrain; black, embryos without forebrain and eyes. (B,C) six3b expression was reduced in embryos injected with mRNA encoding the N-terminus (exons 1-3) of Eaf1 or Eaf2 (B) but was normal in embryos injected with mRNA encoding the C-terminus (exons 4-6) of Eaf1 or Eaf2 (C). (D) The N-terminus (exons 1-3) of Eaf1/2 suppresses forebrain formation by promoting enhanced Wnt/β-catenin activity. (a) Representative embryos showing normal, reduced and increased expression of six3b. (b) Embryos were scored for six3b expression after injection with mRNAs at the dosages indicated. (c) Abnormal expression of six3b in embryos injected with mRNA encoding the N-terminus (exons 1-3) of Eaf1 or Eaf2 was rescued by co-injection with β-catenin1-MO (8 ng/embryo) but not with β-catenin2-MO (8 ng/embryo). Ba-c,Ca-c,Da, dorsal views, anterior to the left. mRNA injections were at 50 pg/embryo unless stated otherwise (Db).