Fig. 5

Myo1G promotes signaling by different Nodal ligands. a, b MZ myo1g mutants display reduced lft1 induction in response to ectopic expression of the Nodal ligands cyclops (cyc, a) and squint (sqt, b). Animal pole views of germ ring stage embryos, arrows indicate patches of ectopic lft1 expression. c qPCR indicates that MZ myo1g mutants present a mild decrease in the endogenous expression levels of the Nodal target gene lft1. Box plots in c indicate mean values ± SD. d, e MZ myo1g mutants present a reduced immunoreactivity for activated Phospho-SMAD2/3 (n = 25 WT and 31 MZ myo1g mutant embryos from 2 independent experiments). Animal pole views of germ ring stage embryos. Scale bar: 100 µm. f Morpholino knockdown of cyc and sqt (MO cyc + MO sqt) elicits stronger Nodal loss of function phenotypes in MZ myo1g mutants than in WT controls. Nodal loss of function phenotypes at 32 hpf were categorized into five classes: class I (partial cyclopia), class II (complete cyclopia), class III (partial loss of the notochord), class IV (complete loss of the notochord), and class V (loss of posterior neural structures). All p values were obtained using non-directional statistical tests. Complete numerical and statistical information are provided in the Source Data files.