Emma Sinclair MSc Candidate, Bonier Lab Among-species variation in hormone concentrations is associated with urban occurrence in birds Urbanization of natural areas is increasing worldwide, contributing to rapid biodiversity loss. While most wildlife disappears as habitat becomes urbanized, some species survive and even thrive in cities, though the traits that allow them to do so remain poorly understood. Endocrine phenotypes, such as circulating hormone concentrations and sensitivity of endocrine responses, could underlie aspects of ecology, life history, and behaviour that influence organisms’ ability to cope with the challenges of urban habitats. However, to date, comparisons of endocrine phenotypes across urban and non-urban populations within species have revealed no consistent patterns, suggesting that individual and population-level responses to urbanization are complex and likely largely driven by plastic shifts. Here, we investigated the degree to which evolved variation in endocrine phenotypes among species predicts, and potentially contributes to, among-species variation in urban tolerance using a broad analysis of the association between circulating concentrations of baseline corticosterone, stress-induced corticosterone, and testosterone and estimates of urban occurrence for bird species from across the globe. Our results reveal context-dependent links between circulating glucocorticoids and urban tolerance, and lower testosterone concentrations in females from urban-tolerant species, relative to urban-avoidant species. These findings suggest there are multiple strategies for tolerating urban habitats, and indicate that other aspects of the endocrine phenotype, such as the ability to appropriately attenuate responses to urban challenges, might be more important for success in cities. This study provides the first ever among-species comparison of endocrine phenotypes across bird species that differ in their tolerance of urban habitat, offering novel insight into how evolved differences in endocrine traits may impact species’ ability to cope with ongoing urbanization. As the human population expands and many of the world’s natural habitats continue to be developed into urban environments, this knowledge will be crucial in understanding how wildlife will cope with our changing world.
Emily Cervenka MSc Candidate, diCenzo Lab Electrifying the Green Economy: Microbial Manufacture of PHB Bioplastic from CO2-derived Formate Reducing global carbon expenditure requires a dedication to innovation and problem-solving at every level, including a rapid divestment from fossil-based fuels and materials. Fossil carbon-based chemical feedstocks, whose production accounts for 14% of all oil and 8% of all gas demand worldwide, can thus be replaced by carbon-sequestering alternatives that are microbially converted into value-added products. In this work, we aimed to develop such an electro-biohybrid system for the conversion of CO2 to the fully compostable bioplastic, polyhydroxybutyrate (PHB). This system involves the electrochemical reduction of CO2 to formate, which would serve as a feedstock for a PHB-producing microbe. For the microbe, we chose Sinorhizobium meliloti due to its natural ability to grow on a wide range of carbon substrates including formate, its genetic tractability, and its ability to naturally synthesize valuable bioproducts such as PHB. Initial tests revealed that although S. meliloti can use formate as a carbon source, formate concentrations above 20 mM are toxic and inhibit the growth of S. meliloti. There was no significant difference in the growth of S. meliloti when provided 20 mM of commercially available formate compared to electrochemically generated formate, confirming that the electrochemical process did not generate toxic byproducts that would inhibit growth. In ongoing work, we are testing whether S. meliloti accumulates PHB during growth with formate as the sole carbon source. In an effort to increase PHB yield, we are using a S. meliloti mutant lacking the PHB depolymerase gene, which was observed to accumulate more PHB than the wild type in both nitrogen-limiting and nitrogen-excess conditions. Overall, this work contributes to the development of a CO2-to-bioproduct pipeline that might one day displace fossil carbon and transform the petrochemical industry from a carbon-intensive to a carbon neutral operation.
Dr. Richard Feldman, Wildlife Landscape Ecologist Ontario Ministry of Northern Development, Mines, Natural Resources, and Forestry Peterborough, Ontario My pandemic year birding an urban tropical forest and reflections on seven years in the Yucatan Peninsula During the pandemic years of 2020 and 2021, I had the good fortune to be able to conduct weekly bird surveys in a local tropical forest fragment in Merida, Yucatan, Mexico. While most of the urban bird assemblage changed little through the year, every visit still brought surprises as non-urban birds still sometimes wandered into the middle of the city. While birding, I could reflect on the research my students and I have conducted in the Yucatan, attempting to understand how communities change across the Peninsula and across seasons. For example, we have found that, during migration, migratory bird species richness is decoupled from local habitat productivity and individual habitat use is unrelated to local resource availability. However, during winter, species redistribute themselves to match productivity gradients. For the talk, I hope you can explore with me how ecological patterns in a region shaped by spatial and temporal variation in precipitation differ from regions shaped by temperature and get to know a place where some Ontario birds spend the winter.
Bio: Richard is currently a Wildlife Landscape Ecologist with the Ontario Ministry of Northern Development, Mines, Natural Resources, and Forestry in Peterborough, Ontario. He has only just started the position after having spent seven years as a research scientist in the Yucatan Center for Scientific Research in Merida, Yucatan, Mexico. He is an alumnus of Queen’s, having graduated in Biology in 1999. He then went on to complete a Master’s in Forest Science at the University of British Columbia, a PhD at McGill, and post-docs at Trent and the University of Massachusetts Amherst. His main research interest is understanding how the response of species to fine-scale environmental variation depends on broader spatial and temporal gradients, such as latitude and seasons. He uses concepts and tools from landscape genetics, behavioural ecology, community ecology, and macroecology. Isabella Asselstine MSc Candidate, Bendena Lab Investigating the role of neuropeptide receptor 14 (NPR-14) in Caenorhabditis elegans sleep Narcolepsy is a sleep disorder characterized by chronic fatigue and episodes of cataplexy. Through studies in human and animal models, a causative link has been revealed between narcolepsy and decreased orexin signaling. In the model organism Caenorhabditis elegans,a G-protein coupled receptor called neuropeptide receptor 14 (NPR-14) has been identified as a potential ortholog to the human orexin receptor-2 (OX2R). Previous phenotypic analyses of npr-14 knockout strains revealed a marked reduction in adult locomotion and mechanosensory stimulation compared to wildtype strains. This narcoleptic-like phenotype observed in npr-14 knockouts, along with the proposed orthologous relationship to OX2R, suggests that npr-14 is involved in the regulation of sleep in C. elegans. C. elegans displays two distinct sleep pathways: the developmentally timed sleep (DTS) pathway, and the stress induced sleep (SIS) pathway. The objective of my thesis research is to elucidate the role of npr-14 in the DTS and/or SIS pathways. This will be achieved by observing DTS and SIS behaviour in npr-14 knockout worms alone and in combination with known regulators of either pathway. Results of this research may uncover epistatic interactions between NPR-14 and components of DTS/SIS, therefore suggesting its potential position within either pathway. Successful characterization of npr-14’s role in C. elegans sleep may provide a model system in which the pathology of narcolepsy and other fatigue-presenting conditions may be explored.
Thakshila Dharmasena MSc Candidate, Monaghan Lab E3Ks: Conserved multi-taskers Investigating the role of a family of multi-functional enzymes in Arabidopsis thaliana Phosphorylation and ubiquitination are two of the most ubiquitous protein modifications in cells. While phosphorylation is catalyzed by protein kinases, ubiquitination is catalyzed by three subsequent enzymes. In plant cells, there is a proven interplay between protein kinases and E3 ubiquitin ligases, the final enzyme of the ubiquitination series. Generally, protein kinases and E3 ligases are two separate proteins coded by two separate genes. I am interested in a group of unique proteins that contain both kinase and E3 ligase domains in a single protein, hence named ‘E3Ks’. In my study, I focused on understanding the molecular evolution, biochemical and biological functions of this fascinating group of proteins in the model plant Arabidopsis thaliana.
Dr. Steven Kembel Université du Québec a Montréal Life on leaves : what are the drivers of phyllosphere bacterial diversity? The aerial surfaces of plants including leaves (the “phyllosphere”) are an important habitat for bacteria. Leaf-associated bacteria are extremely diverse and perform important ecological functions with implications for host plant health and ecology as well as for ecosystem function, but our understanding of the ecological and evolutionary drivers of plant-microbe associations on leaves has been relatively limited. Here I present two case studies of the factors that drive plant-bacteria associations across spatial and phylogenetic scales. In the first case study, we studied populations of the plant-associated genus Methylobacterium living on tree leaves in Quebec forests. Phylogenetically-informed ecological analyses of Methylobacterium diversity demonstrated the importance of environmental factors including temperature for driving dynamics of these populations in space and time. We observed consistent successional patterns of Methylobacterium on leaves throughout the growing season, which were explained by the evolution of ecological strategies within the genus. In the second case study at broader spatial and phylogenetic scales, we studied how the drivers of plant-bacterial associations on leaves varied along a latitidunal gradient from temperate to tropical forests in China. We found that factors including host plant attributes, the abiotic environment, space, and plant neighborhood effects jointly explained most of the variation in phyllosphere bacterial diversity and biogeography, but the importance of plant host attributes increased strongly with increasing latitude. Most phyllosphere bacteria were host-specialized, and the degree of specificity varied with latitude and host plant rarity. Taken together these results suggest avenues for predicting and managing plant microbiomes under global change.
BIO: Dr. Steven Kembel is Professor of Biological Sciences and Canada Research Chair in Plant Microbiomes at the Université du Quebec à Montréal (UQAM). Dr. Kembel completed his B.Sc. in Botany at the University of Manitoba, a M.Sc. and Ph.D. in Biology at the University of Alberta, followed by postdoctoral fellowships at the University of California, Berkeley and the University of Oregon. His research program focuses on understanding the ecological and evolutionary processes that govern patterns of microbial diversity, and on the effects of microbes on host ecology and function in plant and animal microbiomes. Michelle Cheng MSc Candidate, SMOL LAB Assessing lake ecosystem recovery from acidification and responses to emerging environmental stressors in a suite of lakes from Sudbury, Ontario, Canada Mining and smelting activities have strongly influenced the Sudbury (Ontario, Canada) region since the late 19th century, leading to acidification and metal contamination in many local ecosystems. Regulations on restricting acidic emissions were enacted in the 1970s, after which a considerable volume of paleolimnological work was completed to study the impacts of acidification and metal deposition on Sudbury-region lakes and their subsequent biological recovery. Twenty years after the last regional diatom-based assessment, many lakes have undergone large changes in limnological variables, including increases in pH and dissolved organic carbon concentrations, as well as decreases in metal concentrations. Additionally, these lakes are under the potential impacts of newly emerging environmental stressors such as climate warming and road salt contamination. Here, I revisited a suite of Sudbury-region lakes (n=80) by examining their current water chemistry and diatom assemblages preserved in surface sediments. A canonical correspondence analysis was used to assess the relationships between diatom assemblage composition and environmental variables. Although the pH gradient in my study lakes is shorter than earlier calibration studies conducted in this region by more than one pH unit, lakewater pH was still identified as the strongest environmental variable shaping diatom distributions and so was used to construct a robust inference model (R2boot=0.73; RMSEP=0.32). By assessing ecological changes experienced by Sudbury-region lakes over the past few decades, I identified two major trends: an overall increase in diatom-inferred pH, and a rise in the relative abundance of planktonic taxa. Lastly, several down-core analyses were conducted to assess detailed ecological changes of Sudbury-region lakes over the past ~150 years. Although some lakes are tracking recovery in diatom assemblages, other lakes have less clear ecosystem trajectories.
Bryan Hau MSc Candidate, Snedden Lab Investigating the interaction of Arabidopsis calmodulin-like (CML) proteins with calmodulin-binding transcription activators (CAMTAs) Understanding the myriad ways that organisms detect and interpret information from their environment is an ongoing goal of cell biology. A common theme among eukaryotic cells is the use of calcium ions (Ca2+) as second messengers to coordinate responses during information processing. In plants, Ca2+ signals are evoked during responses to abiotic and biotic stresses and during development. These signals are detected by Ca2+-binding proteins (sensors), such as the evolutionarily-conserved protein calmodulin (CaM), which regulates various downstream target proteins to organize signal transduction pathways. In addition to CaM, plants have evolved a remarkable array of CaM-like proteins (CMLs) that are not found in animals. The genetic model, Arabidopsis, has seven CaMs and 50 CMLs, most of which remain unstudied. Why do plants need so many of these Ca2+ sensors? What are their downstream targets? How do they contribute to Ca2+ signaling during stimulus response? Research on CML structure/function is needed to develop a broader understanding of how plants respond to environmental cues. Recently, our lab has been exploring the roles of two paralogs, CML13,14, which possess unique biochemical properties among CaMs and CMLs. To help uncover CML13,14 function, we screened a yeast 2-hybrid library for putative target proteins and discovered 3 families of functionally unrelated proteins that share a common structural feature; tandem IQ domains. IQs are unique CaM binding domains that have been mostly studied in the myosin motor proteins of animals. In addition to myosins, we identified several CaM-binding transcription activators (CAMTAs) as putative CML13,14 targets. CAMTAs possess multiple IQ domains and are important transcription factors in plants that regulate gene expression during abiotic and biotic stresses such as cold, drought, salt stress, pathogen attack, and herbivory. I will present data from my MSc project where I explored the question; are Arabidopsis CAMTAs targets of CML13,14? My project focused mainly on assessing the properties of CML13/14-CAMTA binding, using both in planta and in vitro methods to assess whether the interaction may be physiologically relevant. Collectively, my data supports the hypothesis that CAMTAs and CMLs interact in plants and suggests a novel mechanism through which Ca2+ signals regulate gene expression during stress response.
Dr. Emilie Snell-Rood University of Minnesota Responses to novel and changing environments: predicting how plasticity may interact with evolutionary change Why do some organisms thrive in novel and changing environments while others do not? While both plastic and evolutionary changes may allow populations to survive and diversify in new conditions, it is not always clear how these processes interact. In this talk, I walk through how a deeper understanding of the underlying mechanism of plasticity has implications for thinking about costs, life history tradeoffs, and the precision of a trait match to a new environment. Using examples from behavioral and physiological plasticity in butterflies, and resource variation across butterfly species, I will discuss how a more developmental perspective can help us to move forward in thinking about how plasticity affects evolution in novel environments.
Bio: Emilie Snell-Rood is an Associate Professor of Ecology, Evolution and Behavior at the University of Minnesota. She received her bachelors in biology at the College of William and Mary in Virginia and a PhD in Ecology and Evolutionary Biology from University of Arizona. She did a postdoc at Indiana University before starting her position at Minnesota in 2011. As she will discuss today, Emilie is interested in why organisms vary in developmental flexibility and what this means for survival in new environments. She has worked on a range of systems including butterflies, dung beetles, birds, and mammals. In the educational space, she is also developing materials for collaborative interactions between biology and bio-inspired design. Dr. Landon Getz, Dalhousie University Editing Nature: Genetically Modified Mosquitoes and a Case for Slow Science Mosquito-borne diseases - malaria, dengue fever, zika, and others - are a significant burden on global health and economies. As such, a variety of interventions that target and reduce mosquito populations have been developed and used to manage disease transmission and its consequences. The advent of new genetic technologies, like CRISPR/Cas9, provide innovative solutions to mosquito control and have shown significant promise in reducing mosquito populations. However, these interventions require the release of genetically-modified mosquitoes into shared spaces and carry significant uncertainty and risk. The promise and peril of these interventions make them an excellent case study for how we do science, and how we ought to do science. Taking a "Slow Science" approach to editing nature can help ensure that it is done safely, ethically, and with the support of the communities involved.
BIO: Landon J. Getz, Vanier Scholar and Killam Laureate Landon Getz is a PhD Candidate at Dalhousie University in the Department of Microbiology and Immunology. His research investigates the environmental survival mechanisms of the marine prokaryote Vibrio parahaemolyticus and how these mechanisms to can lead to virulence in human hosts. Landon is a member of the Chief Science Advisor's Youth Council and has a keen interest in science's interconnectedness with politics, policy, and ethics. As such, Landon has explored ethical and justice issues related to gene-editing in humans, as well as the social, environmental, and ethical issues associated with gene-editing in insects (primarily mosquitoes). |
Categories
All
Archives
April 2024
|