embryos after prior methods (
2013
Systems), goat anti-FOXA2 (M-20, sc-6554; Santa Cruz), goat anti-SOX1 (AF3369;
R&D Systems), rabbit anti-Ki67 (90584; Thermo), rabbit anti-phospho-Histone
H3 (06–570; Millipore), and rabbit anti-cleaved Caspase 3 (9661; Cell
Signaling). Immunofluorescence imaging was performed on a Zeiss Axio Imager
Z1.