Patterning and Organogenesis of the Mammalian Embryo

The development of a single cell to a multi-cellular organism, with each tissue and organ having a distinct architecture and function, is truly remarkable. Cells must co-operate and communicate with one another so they divide, migrate, form connections, change their identity, and die in co-ordinated patterns. These processes are complex, thus little is known about developing embryos and the genes that regulate their development. As an MSFHR-funded scholar, Dr. Pamela Hoodless examined how cells communicate with one another during embryonic development. This work continues, with a focus on two areas: the gut and heart. Congenital heart defects occur in about one per cent of births, making it a most common form of birth defect. With genomic technology, Dr. Hoodless can look closely at the genes involved in forming the valves and septa in the heart. She has identified two genes that control the activity of other genes, known as transcription factors, and is studying the functions of these genes in valve formation. Dr. Hoodless is also working to understand how the first stem cells of the gut are formed, and how these cells change to become other organs (liver, pancreas, stomach, etc). Identified for further study are three genes that are expressed (turned on) in these tissues, but not in the development of other body tissues. Understanding how gene regulation controls the development of the heart and gut in the embryo has far reaching implications for medical therapies, ranging from refining the repair of congenital defects to promising technologies such as stem cell therapies and tissue engineering.