Grant: Discovery Grants Program - Individual

My long-term goal is to understand the mechanisms behind symbiosis affecting resistance to disease and environmental stressors. Microbes are on and in all multicellular organisms. Although the ecological roles of symbiotic microbes are mainly unknown, numerous examples of host-microbial communities both positively and negatively affect host fitness. Host animals tend to be selective environments for their microbes; hosts tend to have some bacteria associated with them across their range (e.g., core microbiome), with the other bacteria being more variable and site-specific (e.g., transient bacteria). Early colonization of microbiota may affect the immune system and cause disease consequences later in life. My short-term goals are to: 1.Understand mechanisms of how host-associated microbiomes are assembled and maintained 2.Understand how host factors and microbes interact when those combinations result in disease defense 3.Understand how biologically relevant stressors affect community composition, function, and long-term health of the host Columbia spotted frogs (CSF) will be used as a model system to test whether the host influences skin microbiota and whether the skin microbiota and the host immune system interact to inhibit a fungal pathogen. This will be done using a bank of antimicrobial peptides (AMPs) from wild frogs, where the bacterial community composition and disease status is already known. In addition, we will test how environmental factors, like temperature, affect AMP bacterial interactions. Pacific oysters will be used as a model system to test whether oysters' genotype affects community composition and whether microbiota affects long-term health. Factorial experiments will be done at the Deep Bay Marine Field Station to determine whether the host genotype selects for the oyster microbiome- this will be followed up with in-vivo Vibrio assays to determine if the host or microbiome is more vital in disease defense. This will lead to factorial experiments to test how environmental stressors associated with climate change, such as salinity, pH, and temperature, affect the oyster microbiome and disease susceptibility. Using diverse systems (e.g., amphibians, bivalves), my research tests whether fundamental ecological principles explain relationships between microbes and hosts and how disturbances affect host-microbial communities and function. In addition, the implications of my work have enormous tangible benefits to Canadians and our continued sustainable use of natural resources through the restoration of an endangered species and increasing the resistance and resilience of fisheries to climate change.