Effect of Glce overexpression on embryo morphogenesis and HS composition. Embryos at 1-2 cells stage were injected with glce-A and/or glce-B mRNA and observed at 24 hpf. (a) wild type embryo. (b,c) mild and moderately ventralized embryos showing enlarged blood sac (indicated by an arrow). (d) Severely ventralized embryos displaying dramatically reduced head and trunk. (e-g) High-contrast images of the somites and the notocord (nt) structures in control (e), and in mildly and moderately ventralized embryos (f,g). Note the loss of chevron-like structure of the somites and the narrowing or disappearance of the notocord in embryos overexpressing glce (f,g). (h) Epimerase enzymatic activity at 10 hpf in controls (WT) and in embryos injected with glce-A plus glce-B mRNA (250 pg each). The enzymatic assay was performed as described in Fig. 2b. (i-t) Whole mount in-situ hybridization with D/V markers in embryos during gastrulation and at 5 somite stage. Top row: wild type embryos. Bottom row: embryos injected with 250 pg each of glce-A and glce-B mRNA. (i,j) eve1 staining viewed from the animal pole at shield stage. The arrowheads point to the edges of the expression range of the marker; (k,l) bmp2b, lateral view with the dorsal side to the right at 70% epiboly; (m,n) fkd3, animal pole view at 70% epiboly; (o,p) chordino, dorsal view at 50% epiboly; (q,r) krox-20/opl double staining (head view) and (s,t) myo-D (dorsal view) in embryos at 5 somite stage. Note in (r) the narrow expression domain of krox20 in embryos injected with glce mRNA whereas opl transcript is undetectable.
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