Fig. S11

PGC migration at early developmental stages does not require endoderm.

(a, c) Whole-mount in situ hybridization of nos3 as a PGC marker (asterisks) and sox17 as an endodermal marker (blue rim around the yolk in a), both stained in blue. Animal views are shown. (b, d) Hematoxylin and Eosin Counterstained histological sections of embryos following WISH using nos3 (asterisks) and sox17 (blue cells in b) probes. (a-b) Wild-type PGCs migrate in the vicinity of the yolk in close contact with endodermal cells. Number of embryos examined in a: N=20 and b: N=3. (c-d) In sox32 mutant embryos lacking the endoderm PGCs migrate close to the yolk. c: N=20; d: N=10 (e) 3D Confocal Z-stacks of wild-type embryos in the lateral view. Embryos of transgenic fish with EGFP-labeled PGCs are injected with secfp RNA together with an activated taram-A transcript (taram-A*) into one blastomere at 32/ 64-cell stage for endodermal cell labeling, followed by YSL nuclei labeling with h2b-mcherry RNA upon injection into the yolk. PGCs (in green) are positioned among scattered endodermal cells (shown in red) and in the same layer with them, directly above the YSL nuclei (shown in blue) (N=4). Images were processed using Imaris. Scale bars 25μm. Embryos at 70-80% epiboly in all experiments.