Why do endocrine traits vary within a population?
If changes in circulating hormones regulate animals’ responses to their environments, then why do individuals that live together differ in their endocrine phenotypes? In a recently published paper, Queen’s Biology Associate Professor Fran Bonier and coauthor Dr. Bob Cox of the Department of Biology at the University of Virginia develop two hypotheses, suggesting that variation in endocrine traits within a population can occur because each individual expresses its own context-dependent optimal phenotype, or because some individuals' phenotypes reflect constraint or maladaptation and natural selection on these traits is ongoing. To test the first of these hypotheses, they conducted a meta-analysis of field experiments to see whether hormone manipulations move animals away from their optimal endocrine phenotypes. From Fran, “Overall, hormone manipulations generally reduce fitness, suggesting individuals do express optimal endocrine phenotypes. However, some of the variation from this average effect was equally interesting, and points to sex-specific differences in the ways that hormones regulate life history.” For more, check out the paper in Molecular and Cellular Endocrinology.
Visit the Bonier lab website to learn more about Fran’s work.
Characterizing the Holocene climate of Northeastern Ontario
Despite its susceptibility to human-induced climate change, past conditions of the boreal forest region of Canada are not fully understood. Changes that occurred during the Holocene Thermal Maximum are of particular interest, as this previous period of enhanced warming may help us to forecast how present day climate warming may affect the region. Recent Queen’s Biology graduate Brett Elmslie and current Queen’s Biology PhD Candidate Cale Gushulak work to better understand the conditions of the Holocene Thermal Maximum in the boreal forest region of Northeastern Ontario using fossilized pollen, diatoms, and sedimentary pigments to characterize changes that occurred in Charland Lake. From Cale, “The results of this work are very interesting as they show the importance that the landscape has on the sedimentary record in lake systems.” To learn more, read their article in The Holocene.
In addition to Brett and Cale, this paper was authored by Maxime P. Boreux of the Paleoecological Environmental Assessment and Research Laboratory and the Department of Geography and Planning at Queen’s University, Scott Lamoreux of the Queen’s University Department of Geography and Planning, Peter R. Leavitt of the Institute of Environmental Change and Society at the University of Regina and the Institute for Global Food Security at Queen’s University Belfast, and Brian F. Cumming of the Paleoecological Environmental Assessment and Research Laboratory at Queen’s University. This work was part of Brett Elmslie’s MSc work and Cale Gushulak’s PhD work in the Cumming Lab in the Queen’s Biology Department.
A family of protein kinases key to plant immune signaling
The ability to guard against disease-causing pathogens is essential for plants living in microbe-rich environments. Learning about what signalling pathways are involved in the detection of these stressors is key to understanding plant immune responses. In a recently published review, Queen’s Biology Postdoctoral Fellow Melissa Bredow and Assistant Professor of Plant Biology Jacqueline Monaghan contribute to this goal, detailing the role that calcium-dependent protein kinases play in the regulation of plant immune signalling. To learn more, read the review in Molecular Plant-Microbe Interactions.
This publication is part of Melissa Bredow’s postdoctoral work in the Monaghan lab in the Queen’s Biology Department.
Are Mandt’s black guillemots evolving to breed earlier?
The changing climate presents a formidable challenge to many species, which must adjust their phenology to match their changing environments. Teasing apart whether observed adjustments result from plasticity or true evolutionary change is key in understanding a population’s capacity to overcome this obstacle. In a recently published paper, Queen’s Biology graduate student Drew Sauve and colleagues use a long-term dataset to test whether changes in environmental conditions have led to the evolution of earlier breeding in Mandt’s black guillemots. From Drew, “Our study provides a perspective from the Arctic, where atmospheric temperatures are increasing more rapidly than at lower latitudes. We found that most of the observed change in timing of breeding was driven by changes in individual behaviour in response to annual variation in snowmelt and found little evidence that changes in breeding time are driven by evolutionary change. Unlike many studies, we found evidence of limited genetic variation underlying breeding time, which might limit the ability of evolution to change the timing of breeding in this population. If limited genetic variation is common in Arctic species, the potential for them to respond to ongoing climatic change may be restricted. ” To learn more, read the article in Functional Ecology.
In addition to Drew, this paper was authored by George Divoky of Cooper Island Arctic Research, and Vicki L. Friesen, Queen’s Biology Professor of Evolutionary and Conservation Genetics. This work was part of Drew Sauve’s MSc work in the Friesen lab in the Department of Biology at Queen’s.
For additional coverage of this project and related work visit National Geographic.
Why do members of the same population behave differently?
In nature, we often see members of one population doing very different things. Despite this common observation, however, understanding how behavioural diversity is maintained within a single population has remained a challenge. In a recently published paper, Queen’s Biology graduate Adam Meyer and Queen’s Biology Associate Professor of Population Ecology Bill Nelson use an ingenious experiment to investigate how two different daily movement patterns co-occur in a population of freshwater zooplankton. From Adam, "These behaviours were fascinating to us because they caused animals in the same population to experience extremely different environments. Our experiment used custom built robots and migration tubes to control the migration of thousands of zooplankton. This allowed us to measure the growth associated with each behaviour. To my knowledge, this is the first study to demonstrate experimentally that animals in the same population can obtain the same fitness despite migrating over vastly different environments." To learn more, read their article in Behavioural Ecology.
This work was part of Adam's MSc thesis in the Nelson lab in the Queen's Biology Department.
How can plants better obtain phosphate?
Plants need phosphate (Pi) to grow, but getting enough of this important macronutrient can be difficult. The susceptibility of the soil's organic‐P pool to enzymatic hydrolysis is an important constraint for crop Pi acquisition. Thus, identifying secreted proteins that facilitate root Pi acquisition from the soil's organic-P pool is a key goal in plant science and crop studies. In two recently published papers, Queen’s Biology Postdoctoral Researcher Dr. Mina Ghahremani and colleagues investigate the interaction between a secreted AtPAP26 'glycoform' and the lectin AtGAL1. AtPAP26 is a purple acid phosphatase enzyme of the model plant Arabidopsis that plays a central role in Pi scavenging from extracellular organic-P compounds, whereas lectins are sugar-binding proteins involved in a variety of pivotal biological processes owing to their high affinity and specificity for the attached sugar chains of glycoproteins. From Mina, "This research has provided the first definitive evidence for involvement of glycobiology (i.e. secreted glycoforms or lectins) in plant Pi-starvation responses. Our results support the hypothesis that that binding of AtPAP26's glycans by AtGAL1 enhances AtPAP26 function to facilitate extracellular Pi-scavenging by Pi-starved Arabidopsis”. Learn more about this exciting work in Plant, Cell & Environment here and here.
In addition to Mina, this work was authored by former Plaxton lab post-doc Prof. Joonho Park (Dept. of Fine Chemistry, Seoul National University of Science and Technology); Erin Anderson, Dr. Naomi Marty-Howard, and Prof.Rob Mullen (Dept. of Molecular and Cellular Biology, University of Guelph); former Plaxton lab PhD student Dr. Hue Tran (Oncolytics Biotech Inc.); Dr. Yi-Min She (Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate at Health Canada); and BSc student Sanaz Biglou, MSc student Bryden O’Gallagher, and Prof. William Plaxton of Queen’s University. This work was part of Mina’s PhD thesis research in the Plaxton lab in the Department of Biology at Queen's.
Why are there algal blooms in Dickson Lake?
Algal blooms are becoming alarmingly common in Ontario’s lakes. These rapid accumulations of algae or cyanobacteria can severely harm lake ecosystems, and can be encouraged by a variety of environmental changes. In a recently published paper, Queen’s Biology PhD Candidate Liz Favot and colleagues use a paleolimnological approach to uncover what changes may have accompanied recent cyanobacterial blooms in Algonquin Park’s Dickson Lake. From Liz, “We don't yet have a complete understanding of the environmental triggers for cyanobacterial blooms in low-nutrient systems, but there are indications that climate change is playing a role. Inferences from subfossil diatoms in the paleo record show that nutrient levels have not changed in Dickson Lake over the last two centuries. This finding is important to start to rule out several nutrient-related hypotheses for why the blooms formed (like nutrient pulses from a breached beaver dam, bird guano, or insect frass). We analyzed an additional four proxies (cyanobacterial akinetes, chlorophyll a, non-biting midges, and cladoceran zooplankton) and each gave some indication that the blooms that occurred in Dickson Lake in 2014 and 2015 were unprecedented over the last ~200 years, and that climate warming and ensuing effects on water temperature and thermal structure are potential causal factors”. Learn more about this project in the Journal of Paleolimnology.
In addition to Liz, this work was authored by Dr. Kathleen M. Rühland, Anna M. DeSellas, and Dr. John P. Smol of the Paleoecological Environmental Assessment and Research Laboratory in the Department of Biology at Queen’s, and Ron Ingram and Dr. Andrew M. Paterson of the Dorset Environmental Science Centre. This work is part of Liz’s PhD work in Dr. John Smol’s lab in the Department of Biology at Queen’s.
How does glacial runoff affect lake habitats?
To explore this question, Queen’s Biology PhD Candidate Cécilia Barouillet and colleagues examined how the diversion of a silt-laden river into a clear water lake has influenced the productivity of the lake since its construction in ca. 1930, and used an upstream lake as a reference. From Cécilia, “Our study site offered the perfect setting to explore this question, and it was very exciting to be part of this project. Our results show evidence that the introduction of turbid water into a clear water lake led to a decline of the primary producers (i.e. diatom algae) and primary consumers (i.e. cladoceran zooplankton). The effect of glacial runoff on the basal food-web productivity of a lake have important implications for management questions. For instance, our study lakes sustain Sockeye Salmon populations that have important socio-economical and ecological values in the region, the decline in productivity may have reduced the food resource available for the salmon.” Find the full paper in the Canadian Journal of Fisheries and Aquatic Sciences.
In addition to Cécilia, this work was authored by Dr. Brian F. Cumming and Kathleen R. Laird of the Queen's Biology Paleoecological Envrionmental Assessment and Research Laboratory, Dr. Christopher J. Perrin of Limnotek Research and Development Inc., and Dr. Daniel T. Selbie of Fisheries and Oceans Canada. This work is part of Cécilia's PhD thesis in Brian Cumming's lab in the Department of Biology at Queen's.
Why are tree swallows in decline?
Understanding which aspects of sweeping global change are driving the decline of a given group of organisms is a challenge. Avian aerial insectivores, birds that feed on flying insects, have gained particular attention for their precipitous, but poorly understood decline. In their new paper, recent Queen’s Biology graduate Amelia Cox and colleagues examine changes in a Tree Swallow population at the Queen’s University Biological Station over 40 years to understand this phenomenon. From Amelia, “Climate change isn't just about changing temperatures. Increasing spring rainfall is the reality for our region, and for birds like Tree Swallows, this can mean nestlings starve”. Learn more about this project in Proceedings of the Royal Society B.
In addition to Amelia Cox, this work was coauthored by emeritus professor Dr. Raleigh Robertson who began the Tree Swallow study in 1975, Dr. Ádám Lendvai at the University of Debrecen, Hungary, Queen's undergraduate student Kennedy Everitt, and Dr. Fran Bonier in the Department of Biology at Queen's. This work was part of Amelia’s MSc thesis in Fran Bonier’s lab.
Check out other coverage of this work here.
Best practices for studying plant enzymes
Isolating and studying enzymes can be a tricky business, especially in plants whose enzymes are particularly prone to unwanted proteolysis (partial degradation) following their extraction. This seminal review, by Queen’s Biology Professor and Research Chair of Plant Biochemistry Bill Plaxton, tackles this key challenge in the plant sciences by discussing: (i) how partial proteolysis by endogenous proteases can lead to marked, artefactual alterations to an enzyme’s biochemical and kinetic/regulatory properties, and (ii) practical advice on how to detect and prevent unwanted proteolysis during enzyme extraction and purification from plant. For more, check out his article in Plant and Cell Physiology and visit the Plaxton lab website.
Why do some birds migrate?
Migration is a taxing and dangerous behaviour, but struggling through an inhospitable winter can be even more difficult. In animals that have the opportunity to either remain on their breeding grounds year-round or move to more tolerable environments for the winter, what determines who stays and who leaves? Recent Queen’s Biology graduate Dr. Catherine Dale and colleagues studied a partially migratory population of western bluebirds to learn about what environmental and individual conditions may tip the scales of this trade-off. From Catherine, “The bluebirds in the Okanagan Valley represented a great chance to investigate the factors shaping migratory strategies in partial migrants. We learned a lot about what determines where individual birds spend the winter, were able to interact with many wonderful bluebird box owners and monitors, and also got the chance to work in one of the most beautiful parts of the country!” Read more about Catherine’s work in the Journal of Avian Biology. This work was part of Catherine's PhD thesis research with emeritus professor Dr. Laurene Ratcliffe.
Catherine is also a co-founder of the Dispatches from the Field blog, which is dedicated to sharing the unique experiences of field biologists around the world. Check out the blog and follow @fieldworkblog to learn about some awesome field adventures, including Catherine's!
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