In a study of early embryonic development in primates, an international research team under the leadership of Berthold ...

Once removed from the blastocyst they lack the outer trophoblast ... be "nudged" into becoming any cell type found in the human body. These are the cells that Thomson used in his research.

But studying human gastrulation has proven both technologically ... Prior to implantation, an embryo is a ball of about 250 cells organized as a blastocyst. This elusive ball of cells was ...