Chair of the Biochemistry/Microbiology Department
Professor, joint appointment in Biochemistry/Microbiology and Biology departments
Phone: (250) 721-7105
Research area: cell signalling, developmental biology
The field of developmental biology has changed enormously since the ‘70s when Dr. Robert Burke was first drawn to it.
At that time, the question of how a fertilized egg transforms into a complex organism was a complete mystery.
Consider it: the first cells of an embryo are undifferentiated. As they divide, how do some turn into heart tissue, while others become a liver? How do they end up in the right place?
Over the years, Burke has watched the research become increasingly molecular and less mysterious: cells know who they are and what they should do by comparing notes with their neighbours. Cells do this by using a network of chemical signalling molecules that bind to receptors on cell surfaces.
Burke’s lab examines how the interactions between signalling molecules and receptors guide cell movement during early development. More specifically, lately Burke has concentrated on integrins and Eph receptors.
However, recently, his research has shifted in scale from examining single receptor-signal interactions to a proteomic approach: collecting snapshots of all the proteins active at any given point of development.
This approach was given a boost last November (2006) when an international team (with a UVic contingent led by Burke) published the sea urchin genome in Science. The lowly sea urchin, Strongylocentrotus purpuratus, has been an enduring model organism for developmental researchers because of its simplicity, yet similarity to higher animals including humans. In fact, upon completion of the sea urchin sequence, Burke was surprised to see just how similar the sea urchin was to humans: 70 per cent of sea urchin genes have human equivalents, meaning the research on sea urchins is more relevant to humans than previously thought.
For Burke, the sea urchin sequence has already proved a powerful tool. For example, when an egg interacts with a sperm, one dramatic response is the immediate release of calcium, launching cell division. Burke recently used the sea urchin sequence to predict the sea urchin’s “calcium toolkit,” in other words, the signalling molecules that control and respond to this calcium release. He then used proteomic techniques to confirm these proteins were present in eggs during fertilization.
Burke is an advocate of the pursuit of basic knowledge without a specific application in mind. He says that fundamental biological discoveries have had the greatest impact on society. That’s certainly true for developmental biology, which has applications such as stem cell therapies.
Stem cells are primal cells that have the potential to grow into specialized cells, depending on the signal they receive. The first stem cell therapies emerged in the ‘90s and involved blood stem cells to replenish the immune system in leukemia patients.
Burke points out that much of what is understood about manipulating stem cells comes from understanding how cells in an embryo grow and differentiate into an adult. In fact, looked at another way, you could call developmental biologists the ultimate stem cell researchers, starting with the mother of all stem cells – the egg.