Imprinting to new sensory cues using ancient physiology in a model fish

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The olfactory sense is an invaluable route by which animals gather external chemical information to make decisions. Odorants are central to feeding, avoiding predators and contaminants, migration and mating. My research has shown that a diversity of human-sourced chemicals and effluents evoke olfactory responses in fishes. The central question I aim to address with this proposed research is how does ancient machinery', i.e. evolutionarily-produced proteins and transduction machinery, function when exposed to chemicals of human origin?******Human activities lead to the release of a huge diversity of chemicals into the hydrosphere, but we have little understanding of what this does to fish behaviour. We know that some of our inputs impair the use or gathering of information, but we also know that some of our chemicals and effluents appear to act as odorants. The proposed research will generate knowledge about the relationship between fish olfaction and behavior in the context of human-sourced chemicals. There are two main objectives addressed in this proposal: 1) to link behavioural and physiological olfactory responses to human-sourced odourants'; and 2) to identify the pathways by which these responses are evoked or impaired.******No studies to date have examined whether fish can imprint to human-sourced pollutants. We will use water-soluble fractions of crude oil as well as oil-sands process-affected water to help answer this question. There is conflicting data on the role of olfaction in imprinting to novel odorants; we plan to use two approaches to confirm (or refute) the role of olfaction in imprinting. First, we will identify whether olfactory tissue is responsive to our suite of odorants. We will use CaMPARI technology to identify recently active olfactory neurons in olfactory and brain tissue. We will also use transgenic fish that when given heat-shock as embryos, express a dominant negative thyroid hormone receptor. Once we identify putative imprinting chemicals, we will carryout the imprinting experiments using imprinting knock-out fish.***To identify the pathways by which olfactory responses are evoked or blocked, we will employ transcriptome sequencing to identify olfactory receptor gene expression and those associated with signaling pathways are assess whether they are upregulated in response to odorants. Our expectation is that we will identify genes of specific olfactory receptors and/or their associated pathways that have altered expression. Overall, this research will help elucidate how fish sense and respond to human-sourced modern' stimuli.