The primitive streak, a structure that emerges during mammalian and avian gastrulation, might be a byproduct rather than a landmark of the embryonic development process.
Using human pluripotent stem cells, scientists engineered an amniotic sac-like structure, potentially useful for uncovering the elusive cellular signals that lead to infertility.
Scientists issue a call to reconsider the rules governing the creation of tissues, organs, and other structures made possible by recent advances in synthetic biology.