Janet Rossant discusses the nature of discovery science, as exemplified by her obsession with blastocysts and how it led to the discovery of a new placental stem cell type.

Janet Rossant is a senior scientist in the Developmental and Stem Cell Biology program at the Hospital for Sick Children and the first woman to receive the Canada Gairdner Wightman Award. Her research revolves around understanding genetic control of normal and abnormal development in the early mouse embryo and has resulted in the discovery of a new placental stem cell type called the trophoblast stem cell.