Keynote talk 2: The primitive streak: - An interface between technology, embryology and morality

The primitive streak is a transitory structure in human embryonic development where the earliest signs of pluriopotency loss and tissue differentiation are observed. Its appearance is viewed by government regulatory bodies as the beginning of human individuality in ethical and moral debates. Technological advances in ES/iPS cell biology have made it easy to revert terminally differentiated cells back to this peri-pluripotent/primitive streak state, bringing modern biology to an unchartered territory with equal promises and challenges. In this talk, I will give an embryological overview of the primitive streak and of how it turns pluripotent epiblast cells into mesoderm cells (bones, muscles and blood). I will also present our recent data on generating ectopic primitive streak and creating conjoined twins using animal models. Finally, I will discuss how future technological improvement can maximize social benefits and minimize moral dilemma of breakthroughs in biological research.