develops from start stage end stage forerunner cell group TAO:0000023 forerunner cells ZFA:0000023 A group of cells that migrate at the leading edge of shield during gastrulation but do not involute. At the end of gastrulation, forerunner cells migrate deep into the embryo and organize to form Kupffer's vesicle. DFCs dorsal forerunner cells zebrafish_anatomy embryonic structure noninvoluting endocytic marginal cell cluster gastrula:50%-epiboly segmentation:1-4 somites