Figure 3.

Endocytosis is necessary for convergent extension movements. Wild-type embryos were incubated from stage 9 to stage 14 in MBSH containing the indicated concentration of genistein (a) or chlorpromazine (b). (c) Quantification of the chordin expression revealed that genistein blocked convergent extension movements even at low doses (50 µM). At high doses (250 µM), almost all embryos showed the severe phenotype with chordin being expressed at the dorsal side of the open blastoporus, whereas 60% of the DMSO-treated siblings expressed chordin in a wild-type pattern. (d) Quantification of the chordin expression revealed that 50 µg/ml chlorpromazine induced a mild mislocalization of chordin expression in more than 60% of the embryos. Doubling of the dose to 100 µg/ml increased the frequency of chordin mislocalization to more than 70%. e) Simultaneous treatment with both inhibitors revealed additive effects. Quantification of chordin mislocalization revealed that both inhibitors together inhibit convergent extension movements even at doses when one inhibitor alone has only mild effects. n: number of embryos, p-values according to χ² test. n.s. not significant,