There are several factors affecting stem cells differentiation during embryonic development stage. I would like to discuss these factors together through your research and your experiences. Either in vivo or in vitro .
Yes , In vivo gene of is considered the most important reasons as well as cellular signals and communication between cells, either in the laboratory , the density of cells in dish , and growth factors used in cell differentiation
From my experience; using feeder cells maintain the normal morphology of oligopotent ESCs (trophoblasts) however using Matrigel (basement membrane matrix) stimulate differentiation into elongated spindle like cells.
I would like to share a time-lapse video I captured during my experiment.