2008 CRRWH Annual Retreat

Dr. Rossant is a world-leading developmental biologist who has made major contributions to our understanding of how an embryo develops, how genes control development and how embryonic and other stem cells arise. A fertilized egg divides many times to produce a ball of embryonic cells that are genetically identical. Yet, these cells become distinctly different as development proceeds. How genes encode and control the information necessary to construct a mammalian eand direct cells to adopt different fates has been the focus of the research carried out by Janet Rossant. When still a graduate student, she conducted now-classic work defining cell lineages and cell fates in the early mouse embryo. Ever since, and throughout her career, she has been a pioneer and innovator of new methods to manipulate and interrogate the mouse genome, which have helped to accord the mouse its stature as the pre-eminent model for studying mammalian development and physiology. She has made major contributions to our current level of understanding about how embryonic cells behave and function, how embryonic axes are established, how stem cells are set aside during development, and how individual tissues are specified. In particular, her research interests centre on understanding the genetic control of normal and abnormal development in the early mouse embryo, work that has shed light on how congenital anomalies in the heart, blood vessels and placenta arise. Her work on the genetic regulation of angiogenesis has been of major importance in defining the signaling pathways that are now clinically relevant targets for chemotherapeutic intervention against solid tumors. Her research on the basic properties of stem cells and how they arise has shown that, in the early embryo, in addition to the pluripotent stem cells in the embryo itself, stem cells also form in the trophoderm layer. The discovery of the existence of these trophoblast stem cells has provided important new insights about development of the placenta and placenta-related pregnacy disorders. In current work, she is using both chemical mutagenesis and insertional mutagenesis with gene trap vectors as a means to generate new mouse mutants that will serve as archetypes to understand the molecular basis of various other human developmental diseases. Dr. Rossant is the Deputy Director of the Canadian Stem Cell Network and the Director of the Centre for Modelling Human Disease in Toronto, which is developing new mouse models of human disease. She is actively involved in the international developmental biology community, serving as Editor of Development for many years and as President of the Society for Developmental Biology in 1996-97. Dr. Rossant also served as Chair of CIHR's Working Group on stem cell research.