Tuesday/Mardi, May/Mai 7
8:30-10:30
CPB symposium
Tribute to Pat Wright
Location/Lieu: Ballroom A and B
Chair/Animé par: Tamzin Blewett (University of Alberta), Suzie Currie (Acadia University)
8:30-8:40
Introduction and Welcome
8:40-9:00
Cosima S. Porteus, Deep Soor, Liam R. Tigert, Gwangseok Yoon, Elissa Khodikian, Arsheen Bozai
Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
The effects of hypoxia and simulated ocean acidification on oxygen sensing and gill morphology of threespine stickleback (Gasterosteus aculeatus)
Dr Pat Wright has been an important mentor to me since the very beginning of my career. During my talk I will reflect on her guidance and the impact she has had on me as a scientist. I will also present some new research from my lab on neuroepithelial cells (NECs), which are the putative oxygen and CO2 chemoreceptors in fish. Responses to conditions such as hypoxia or elevated CO2 have been observed to increase NEC size and/or density in freshwater fish due to an increase cellular activity, but less is known about these cells in marine fish. The NECs of marine threespine sticklebacks (Gasterosteus aculeatus) were characterized using immunohistochemistry. Sticklebacks were exposed to mild (10kPa) or moderate (6.8kPa) hypoxia and two levels of simulated ocean acidification (1,500 and 3,000µatm) to determine if there were changes in NEC size and density, and gill morphology in response to these stressors. The NECs of stickleback contained synaptic vesicles, were innervated, but were larger and more abundant than in other similar sized freshwater fishes. NEC size and density were unaffected by exposure to hypoxia, but there was a significant decrease in interlamellar cell mass (ILCM) in response to hypoxia. NECs increased in size, but not abundance in response to simulated ocean acidification and had larger ILCMs compared to control fish. Our results demonstrated that NECs in adult marine sticklebacks can respond to both hypoxia and CO2 at environmentally relevant levels, which highlights the importance of NECs in marine fishes living in coastal areas.
9:00-9:20
Erin Leonard
Department of Biology, Wilfrid Laurier Biology, Waterloo, Canada
Chemosensing and Pat Wright: both required for success in life
For the CPB Symposium, I aim to honour the profound influence of my mentor, Dr. Pat Wright, in the field of science and beyond. With a focus on chemosensing, I will demonstrate how Pat's pioneering work on Kryptolebias marmoratus provides fundamental principles essential for success in both scientific pursuits and personal development. Pat’s mentorship has taught me that asking thought-provoking scientific questions and formulating clear and testable hypotheses are the cornerstone of great science. I will highlight how her mentorship influenced some of my work expanding the role of neuroepithelial cells (NECs) involved with chemosensing. Arguably, one of the most important downstream responses to changes in chemostimuli is the hypoxic ventilatory response (HVR) which is ubiquitous across fishes and constitutes an increase in ventilation of the respiratory organs. The most well-studied chemoreceptors involved in the HVR are NECs, the putative oxygen sensors of the fish gill. Although the respiratory gases such as oxygen and carbon dioxide have received the most attention, it is becoming clear that other novel, “non-respiratory” stimuli including hydrogen sulfide, nitrogenous wastes such as ammonia, and tissue metabolites such as lactate can also stimulate ventilation in fishes. I will highlight the parallels between the ability to perceive and respond to chemical signals in the environment and the guidance provided by mentors, like Pat, in shaping our paths in life. As we celebrate Pat's contributions to science and mentorship, we recognize the legacy she leaves for future generations of young scientists.
9:20-9:40
Tammy Rodela
St. Francis Xavier University
Fish Tales: Unraveling biological narratives through environmental challenges
Every animal has a biological story to tell: Pat Wright's influence on generations of comparative physiologists has instilled a profound curiosity to understand how animals thrive and survive through a myriad of environmental challenges. My experience as a graduate student in the Wright lab influenced my research interests in the underlying mechanisms used by fish to tolerate multiple environmental stressors. Natural shallow water habitats and slow-flowing streams are susceptible to decreases in ambient oxygen (hypoxia) and the accumulation of environmental ammonia (HEA). Zebrafish (Danio rerio) can tolerate these environments with ease, however, their mechanisms of resiliency to the combined exposures are understudied. We have collected evidence of a mechanistic link underlying tolerance to both hypoxia and HEA exposure in zebrafish. At the whole animal level, sequential exposure to either hypoxia or ammonia resulted in zebrafish being far more tolerant of the other stressor, suggesting the involvement of cross-protective mechanisms. Brain transcriptomic analyses identified convergent gene expression patterns in the oxidative stress response and metabolic pathways. Whole-cell proteomics of the zebrafish brain highlighted significant deacetylation of mitochondrial complex III and hyper-acetylation of complex V following hypoxia and HEA exposures, indicating that post-translational modifications may alter mitochondrial activity. Mitochondrial oxygen binding affinity and emission of reactive oxygen species changed in response to acclimation to individual and combined stressors. These data provide evidence for one facet of cross-protection in zebrafish. From the perspective of a curious comparative physiologist, many questions remain in the zebrafish’s biological narrative and their ability to tolerate multiple stressors.
9:40-10:00
Andy Turko
Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
Physiology of amphibious fishes in the lab and the field
The invasion of land by tetrapods is generally considered to be one of the most dramatic transitions in vertebrate evolution, but we now know that extant amphibious fishes have independently made this transition almost 100 times! I will briefly discuss some of the most exciting discoveries that Pat and I made during a decade of working together studying the physiology of amphibious fishes. In particular, I will discuss our field work in Belize to demonstrate the physiological insights that can be gained by studying animals in their natural environments. For example, we recently found that both aquatic and terrestrial athletic performance strongly depend on local environmental conditions. Finally, I will share some insights into my current research exploring the behaviour and physiology of newly-identified species of amphibious fishes. Overall, I hope to show how my work with Pat has improved our understanding of the physiological adaptations underlying the repeated transition from aquatic to terrestrial life in vertebrates, while also highlighting the many remaining knowledge gaps.
Chair/Animé par: Tamzin Blewett (University of Alberta), Suzie Currie (Acadia University)
8:30-8:40
Introduction and Welcome
8:40-9:00
Cosima S. Porteus, Deep Soor, Liam R. Tigert, Gwangseok Yoon, Elissa Khodikian, Arsheen Bozai
Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
The effects of hypoxia and simulated ocean acidification on oxygen sensing and gill morphology of threespine stickleback (Gasterosteus aculeatus)
Dr Pat Wright has been an important mentor to me since the very beginning of my career. During my talk I will reflect on her guidance and the impact she has had on me as a scientist. I will also present some new research from my lab on neuroepithelial cells (NECs), which are the putative oxygen and CO2 chemoreceptors in fish. Responses to conditions such as hypoxia or elevated CO2 have been observed to increase NEC size and/or density in freshwater fish due to an increase cellular activity, but less is known about these cells in marine fish. The NECs of marine threespine sticklebacks (Gasterosteus aculeatus) were characterized using immunohistochemistry. Sticklebacks were exposed to mild (10kPa) or moderate (6.8kPa) hypoxia and two levels of simulated ocean acidification (1,500 and 3,000µatm) to determine if there were changes in NEC size and density, and gill morphology in response to these stressors. The NECs of stickleback contained synaptic vesicles, were innervated, but were larger and more abundant than in other similar sized freshwater fishes. NEC size and density were unaffected by exposure to hypoxia, but there was a significant decrease in interlamellar cell mass (ILCM) in response to hypoxia. NECs increased in size, but not abundance in response to simulated ocean acidification and had larger ILCMs compared to control fish. Our results demonstrated that NECs in adult marine sticklebacks can respond to both hypoxia and CO2 at environmentally relevant levels, which highlights the importance of NECs in marine fishes living in coastal areas.
9:00-9:20
Erin Leonard
Department of Biology, Wilfrid Laurier Biology, Waterloo, Canada
Chemosensing and Pat Wright: both required for success in life
For the CPB Symposium, I aim to honour the profound influence of my mentor, Dr. Pat Wright, in the field of science and beyond. With a focus on chemosensing, I will demonstrate how Pat's pioneering work on Kryptolebias marmoratus provides fundamental principles essential for success in both scientific pursuits and personal development. Pat’s mentorship has taught me that asking thought-provoking scientific questions and formulating clear and testable hypotheses are the cornerstone of great science. I will highlight how her mentorship influenced some of my work expanding the role of neuroepithelial cells (NECs) involved with chemosensing. Arguably, one of the most important downstream responses to changes in chemostimuli is the hypoxic ventilatory response (HVR) which is ubiquitous across fishes and constitutes an increase in ventilation of the respiratory organs. The most well-studied chemoreceptors involved in the HVR are NECs, the putative oxygen sensors of the fish gill. Although the respiratory gases such as oxygen and carbon dioxide have received the most attention, it is becoming clear that other novel, “non-respiratory” stimuli including hydrogen sulfide, nitrogenous wastes such as ammonia, and tissue metabolites such as lactate can also stimulate ventilation in fishes. I will highlight the parallels between the ability to perceive and respond to chemical signals in the environment and the guidance provided by mentors, like Pat, in shaping our paths in life. As we celebrate Pat's contributions to science and mentorship, we recognize the legacy she leaves for future generations of young scientists.
9:20-9:40
Tammy Rodela
St. Francis Xavier University
Fish Tales: Unraveling biological narratives through environmental challenges
Every animal has a biological story to tell: Pat Wright's influence on generations of comparative physiologists has instilled a profound curiosity to understand how animals thrive and survive through a myriad of environmental challenges. My experience as a graduate student in the Wright lab influenced my research interests in the underlying mechanisms used by fish to tolerate multiple environmental stressors. Natural shallow water habitats and slow-flowing streams are susceptible to decreases in ambient oxygen (hypoxia) and the accumulation of environmental ammonia (HEA). Zebrafish (Danio rerio) can tolerate these environments with ease, however, their mechanisms of resiliency to the combined exposures are understudied. We have collected evidence of a mechanistic link underlying tolerance to both hypoxia and HEA exposure in zebrafish. At the whole animal level, sequential exposure to either hypoxia or ammonia resulted in zebrafish being far more tolerant of the other stressor, suggesting the involvement of cross-protective mechanisms. Brain transcriptomic analyses identified convergent gene expression patterns in the oxidative stress response and metabolic pathways. Whole-cell proteomics of the zebrafish brain highlighted significant deacetylation of mitochondrial complex III and hyper-acetylation of complex V following hypoxia and HEA exposures, indicating that post-translational modifications may alter mitochondrial activity. Mitochondrial oxygen binding affinity and emission of reactive oxygen species changed in response to acclimation to individual and combined stressors. These data provide evidence for one facet of cross-protection in zebrafish. From the perspective of a curious comparative physiologist, many questions remain in the zebrafish’s biological narrative and their ability to tolerate multiple stressors.
9:40-10:00
Andy Turko
Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
Physiology of amphibious fishes in the lab and the field
The invasion of land by tetrapods is generally considered to be one of the most dramatic transitions in vertebrate evolution, but we now know that extant amphibious fishes have independently made this transition almost 100 times! I will briefly discuss some of the most exciting discoveries that Pat and I made during a decade of working together studying the physiology of amphibious fishes. In particular, I will discuss our field work in Belize to demonstrate the physiological insights that can be gained by studying animals in their natural environments. For example, we recently found that both aquatic and terrestrial athletic performance strongly depend on local environmental conditions. Finally, I will share some insights into my current research exploring the behaviour and physiology of newly-identified species of amphibious fishes. Overall, I hope to show how my work with Pat has improved our understanding of the physiological adaptations underlying the repeated transition from aquatic to terrestrial life in vertebrates, while also highlighting the many remaining knowledge gaps.