a mass of inner cells that are distinct from the blastula. The next stage of embryogenesis is formation of the gastrula. Before gastrula formation can occur, the cells of the trophoblast are ...

Permissive H3K4me3 and repressive H3K27me3 histone modifications emerge during blastula and gastrula stages 13,14,15,16. To date, little is known about the origin and specification of the ...