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Blanchard TS, Earhart ML, Shatsky AK, Schulte PM. Intraspecific variation in thermal performance curves for early development in Fundulus heteroclitus. J Exp Zool A Ecol Integr Physiol 2024. [PMID: 38769744 DOI: 10.1002/jez.2827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 04/04/2024] [Accepted: 05/06/2024] [Indexed: 05/22/2024]
Abstract
Thermal performance curves (TPCs) provide a framework for understanding the effects of temperature on ectotherm performance and fitness. TPCs are often used to test hypotheses regarding local adaptation to temperature or to develop predictions for how organisms will respond to climate warming. However, for aquatic organisms such as fishes, most TPCs have been estimated for adult life stages, and little is known about the shape of TPCs or the potential for thermal adaptation at sensitive embryonic life stages. To examine how latitudinal gradients shape TPCs at early life stages in fishes, we used two populations of Fundulus heteroclitus that have been shown to exhibit latitudinal variation along the thermal cline as adults. We exposed embryos from both northern and southern populations and their reciprocal crosses to eight different temperatures (15°C, 18°C, 21°C, 24°C, 27°C, 30°C, 33°C, and 36°C) until hatch and examined the effects of developmental temperature on embryonic and larval traits (shape of TPCs, heart rate, and body size). We found that the pure southern embryos had a right-shifted TPC (higher thermal optimum (Topt) for developmental rate, survival, and embryonic growth rate) whereas pure northern embryos had a vertically shifted TPC (higher maximum performance (Pmax) for developmental rate). Differences across larval traits and cross-type were also found, such that northern crosses hatched faster and hatched at a smaller size compared to the pure southern population. Overall, these observed differences in embryonic and larval traits are consistent with patterns of both local adaptation and countergradient variation.
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Affiliation(s)
- Tessa S Blanchard
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Madison L Earhart
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ariel K Shatsky
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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Metzger DCH, Earhart ML, Schulte PM. Genomic and Epigenomic Influences on Resilience Across Scales: lessons from the responses of fishes to environmental stressors. Integr Comp Biol 2024:icae019. [PMID: 38632046 DOI: 10.1093/icb/icae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024] Open
Abstract
Understanding the factors that influence the resilience of biological systems to environmental change is an increasingly critical concern in the face of increasing human impacts on ecosystems and the organisms that inhabit them. However, most considerations of biological resilience have focused at the community and ecosystem levels, whereas here we discuss how including consideration of processes occurring at lower levels of biological organization may provide insights into factors that influence resilience at higher levels of biological organization. Specifically, we explore how processes at the genomic and epigenomic levels may cascade up to influence resilience at higher levels and ask how the concepts of 'resistance', or the capacity of a system to minimize change in response to a disturbance, and 'recovery', or the ability of a system to return to its original state following a disturbance and avoid tipping points and resulting regime shifts map to these lower levels of biological organization. Overall, we argue that substantial changes at these lower levels may be required to support resilience at higher levels, using selected examples of genomic and epigenomic responses of fish to climate-change relevant stressors such as high temperature and hypoxia at the levels of the genome, epigenome and organism.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, University of British Columbia, Vancouver, BC Canada
| | - Madison L Earhart
- Department of Zoology, University of British Columbia, Vancouver, BC Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC Canada
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3
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Gilmour KM, Daley MA, Egginton S, Kelber A, McHenry MJ, Patek SN, Sane SP, Schulte PM, Terblanche JS, Wright PA, Franklin CE. Through the looking glass: attempting to predict future opportunities and challenges in experimental biology. J Exp Biol 2023; 226:jeb246921. [PMID: 38059428 DOI: 10.1242/jeb.246921] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
To celebrate its centenary year, Journal of Experimental Biology (JEB) commissioned a collection of articles examining the past, present and future of experimental biology. This Commentary closes the collection by considering the important research opportunities and challenges that await us in the future. We expect that researchers will harness the power of technological advances, such as '-omics' and gene editing, to probe resistance and resilience to environmental change as well as other organismal responses. The capacity to handle large data sets will allow high-resolution data to be collected for individual animals and to understand population, species and community responses. The availability of large data sets will also place greater emphasis on approaches such as modeling and simulations. Finally, the increasing sophistication of biologgers will allow more comprehensive data to be collected for individual animals in the wild. Collectively, these approaches will provide an unprecedented understanding of 'how animals work' as well as keys to safeguarding animals at a time when anthropogenic activities are degrading the natural environment.
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Affiliation(s)
| | - Monica A Daley
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Stuart Egginton
- School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Almut Kelber
- Department of Biology, Lund University, 22362 Lund, Sweden
| | - Matthew J McHenry
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Sheila N Patek
- Biology Department, Duke University, Durham, NC 27708, USA
| | - Sanjay P Sane
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, Karnataka 560065, India
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - John S Terblanche
- Center for Invasion Biology, Department of Conservation Ecology & Entomology, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Patricia A Wright
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Craig E Franklin
- School of the Environment, The University of Queensland, St. Lucia, Brisbane 4072, Australia
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Earhart ML, Blanchard TS, Strowbridge N, Sheena R, McMaster C, Staples B, Brauner CJ, Baker DW, Schulte PM. Heatwave resilience of juvenile white sturgeon is associated with epigenetic and transcriptional alterations. Sci Rep 2023; 13:15451. [PMID: 37723229 PMCID: PMC10507091 DOI: 10.1038/s41598-023-42652-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/13/2023] [Indexed: 09/20/2023] Open
Abstract
Heatwaves are increasing in frequency and severity, posing a significant threat to organisms globally. In aquatic environments heatwaves are often associated with low environmental oxygen, which is a deadly combination for fish. However, surprisingly little is known about the capacity of fishes to withstand these interacting stressors. This issue is particularly critical for species of extreme conservation concern such as sturgeon. We assessed the tolerance of juvenile white sturgeon from an endangered population to heatwave exposure and investigated how this exposure affects tolerance to additional acute stressors. We measured whole-animal thermal and hypoxic performance and underlying epigenetic and transcriptional mechanisms. Sturgeon exposed to a simulated heatwave had increased thermal tolerance and exhibited complete compensation for the effects of acute hypoxia. These changes were associated with an increase in mRNA levels involved in thermal and hypoxic stress (hsp90a, hsp90b, hsp70 and hif1a) following these stressors. Global DNA methylation was sensitive to heatwave exposure and rapidly responded to acute thermal and hypoxia stress over the course of an hour. These data demonstrate that juvenile white sturgeon exhibit substantial resilience to heatwaves, associated with improved cross-tolerance to additional acute stressors and involving rapid responses in both epigenetic and transcriptional mechanisms.
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Affiliation(s)
- Madison L Earhart
- Department of Zoology, University of British Columbia, Vancouver, Canada.
| | - Tessa S Blanchard
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Nicholas Strowbridge
- Department of Zoology, University of British Columbia, Vancouver, Canada
- School of Biodiversity, One Health, and Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Ravinder Sheena
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Clark McMaster
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Benjamin Staples
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Daniel W Baker
- Department of Fisheries and Aquaculture, Vancouver Island University, Nanaimo, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, Canada
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Earhart ML, Blanchard TS, Morrison PR, Strowbridge N, Penman RJ, Brauner CJ, Schulte PM, Baker DW. Identification of upper thermal thresholds during development in the endangered Nechako white sturgeon with management implications for a regulated river. Conserv Physiol 2023; 11:coad032. [PMID: 37228298 PMCID: PMC10205467 DOI: 10.1093/conphys/coad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/20/2023] [Accepted: 04/27/2023] [Indexed: 05/27/2023]
Abstract
Climate change-induced warming effects are already evident in river ecosystems, and projected increases in temperature will continue to amplify stress on fish communities. In addition, many rivers globally are impacted by dams, which have many negative effects on fishes by altering flow, blocking fish passage, and changing sediment composition. However, in some systems, dams present an opportunity to manage river temperature through regulated releases of cooler water. For example, there is a government mandate for Kenney dam operators in the Nechako river, British Columbia, Canada, to maintain river temperature <20°C in July and August to protect migrating sockeye salmon (Oncorhynchus nerka). However, there is another endangered fish species inhabiting the same river, Nechako white sturgeon (Acipenser transmontanus), and it is unclear if these current temperature regulations, or timing of the regulations, are suitable for spawning and developing sturgeon. In this study, we aimed to identify upper thermal thresholds in white sturgeon embryos and larvae to investigate if exposure to current river temperatures are playing a role in recruitment failure. We incubated embryos and yolk-sac larvae in three environmentally relevant temperatures (14, 18 and 21°C) throughout development to identify thermal thresholds across different levels of biological organization. Our results demonstrate upper thermal thresholds at 21°C across physiological measurements in embryo and yolk-sac larvae white sturgeon. Before hatch, both embryo survival and metabolic rate were reduced at 21°C. After hatch, sublethal consequences continued at 21°C because larval sturgeon had decreased thermal plasticity and a dampened transcriptional response during development. In recent years, the Nechako river has reached 21°C by the end of June, and at this temperature, a decrease in sturgeon performance is evident in most of the traits measured. As such, the thermal thresholds identified here suggest current temperature regulations may not be suitable for developing white sturgeon and future recruitment.
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Affiliation(s)
- Madison L Earhart
- Corresponding author: Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada. . Tel.: 204-799-9338
| | - Tessa S Blanchard
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Phillip R Morrison
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- Department of Resource Management and Protection, and Biology Department, Vancouver Island University, 900 Fifth Street Nanaimo, BC V9R 5S5, Canada
| | - Nicholas Strowbridge
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- School of Biodiversity, One Health, & Veterinary Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK
| | - Rachael J Penman
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
- Instreams fisheries research, 2323 Boundary Rd Unit 115, Vancouver, BC V5M 4V8, Canada
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, BC V6T 1Z4, Canada
| | - Daniel W Baker
- Department of Fisheries and Aquaculture, Vancouver Island University, 900 Fifth Street, Nanaimo, BC V9R 5S5, Canada
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Earhart ML, Blanchard TS, Harman AA, Schulte PM. Hypoxia and High Temperature as Interacting Stressors: Will Plasticity Promote Resilience of Fishes in a Changing World? Biol Bull 2022; 243:149-170. [PMID: 36548973 DOI: 10.1086/722115] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
AbstractDetermining the resilience of a species or population to climate change stressors is an important but difficult task because resilience can be affected both by genetically based variation and by various types of phenotypic plasticity. In addition, most of what is known about organismal responses is for single stressors in isolation, but environmental change involves multiple environmental factors acting in combination. Here, our goal is to summarize what is known about phenotypic plasticity in fishes in response to high temperature and low oxygen (hypoxia) in combination across multiple timescales, to ask how much resilience plasticity may provide in the face of climate change. There are relatively few studies investigating plasticity in response to these environmental stressors in combination; but the available data suggest that although fish have some capacity to adjust their phenotype and compensate for the negative effects of acute exposure to high temperature and hypoxia through acclimation or developmental plasticity, compensation is generally only partial. There is very little known about intergenerational and transgenerational effects, although studies on each stressor in isolation suggest that both positive and negative impacts may occur. Overall, the capacity for phenotypic plasticity in response to these two stressors is highly variable among species and extremely dependent on the specific context of the experiment, including the extent and timing of stressor exposure. This variability in the nature and extent of plasticity suggests that existing phenotypic plasticity is unlikely to adequately buffer fishes against the combined stressors of high temperature and hypoxia as our climate warms.
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Woods HA, Moran AL, Atkinson D, Audzijonyte A, Berenbrink M, Borges FO, Burnett KG, Burnett LE, Coates CJ, Collin R, Costa-Paiva EM, Duncan MI, Ern R, Laetz EMJ, Levin LA, Lindmark M, Lucey NM, McCormick LR, Pierson JJ, Rosa R, Roman MR, Sampaio E, Schulte PM, Sperling EA, Walczyńska A, Verberk WCEP. Integrative Approaches to Understanding Organismal Responses to Aquatic Deoxygenation. Biol Bull 2022; 243:85-103. [PMID: 36548975 DOI: 10.1086/722899] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
AbstractOxygen bioavailability is declining in aquatic systems worldwide as a result of climate change and other anthropogenic stressors. For aquatic organisms, the consequences are poorly known but are likely to reflect both direct effects of declining oxygen bioavailability and interactions between oxygen and other stressors, including two-warming and acidification-that have received substantial attention in recent decades and that typically accompany oxygen changes. Drawing on the collected papers in this symposium volume ("An Oxygen Perspective on Climate Change"), we outline the causes and consequences of declining oxygen bioavailability. First, we discuss the scope of natural and predicted anthropogenic changes in aquatic oxygen levels. Although modern organisms are the result of long evolutionary histories during which they were exposed to natural oxygen regimes, anthropogenic change is now exposing them to more extreme conditions and novel combinations of low oxygen with other stressors. Second, we identify behavioral and physiological mechanisms that underlie the interactive effects of oxygen with other stressors, and we assess the range of potential organismal responses to oxygen limitation that occur across levels of biological organization and over multiple timescales. We argue that metabolism and energetics provide a powerful and unifying framework for understanding organism-oxygen interactions. Third, we conclude by outlining a set of approaches for maximizing the effectiveness of future work, including focusing on long-term experiments using biologically realistic variation in experimental factors and taking truly cross-disciplinary and integrative approaches to understanding and predicting future effects.
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Earhart ML, Blanchard TS, Strowbridge N, Bugg WS, Schulte PM. Gene expression and latitudinal variation in the stress response in Fundulus heteroclitus. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111188. [PMID: 35304270 DOI: 10.1016/j.cbpa.2022.111188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 10/18/2022]
Abstract
Atlantic killifish, Fundulus heteroclitus, are intertidal marsh fish found along the east coast of North America. Associated with the thermal gradient along this coast, northern and southern killifish populations are known to differ in morphology, behavior, and physiology, including in their cortisol stress response. Our goal was to explore population differences in the stress response and identify underlying molecular mechanisms. We measured responses to both acute and repeated stress in plasma cortisol, stress axis mRNA expression, and body condition in northern and southern killifish. Following an acute stressor, the southern population had higher cortisol levels than the northern population but there was no difference between populations following repeated stress. In the brain, both corticotropin releasing factor and its binding protein had higher expression in the southern than the northern population, but the northern population showed more changes in mRNA levels following a stressor. In the head kidney, Melanocortin 2 Receptor and steroidogenic acute regulatory protein mRNA levels were higher in the southern population suggesting a larger capacity for cortisol synthesis than in the northern fish. Lastly, the glucocorticoid receptor GR1 mRNA levels were greater in the liver of southern fish, suggesting a greater capacity to respond to cortisol, and GR2 had differential expression in the head kidney, suggesting an interpopulation difference in stress axis negative feedback loops. Southern, but not northern, fish were able to maintain body condition following stress, suggesting that these differences in the stress response may be important for adaptation across latitudes.
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Affiliation(s)
- Madison L Earhart
- Department of Zoology, University of British Columba, Vancouver, Canada.
| | - Tessa S Blanchard
- Department of Zoology, University of British Columba, Vancouver, Canada
| | - Nicholas Strowbridge
- Department of Zoology, University of British Columba, Vancouver, Canada; Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasglow, Glasglow, UK
| | - William S Bugg
- Department of Zoology, University of British Columba, Vancouver, Canada; Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
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Strowbridge N, Northrup SL, Earhart ML, Blanchard TS, Schulte PM. Acute measures of upper thermal and hypoxia tolerance are not reliable predictors of mortality following environmental challenges in rainbow trout ( Oncorhynchus mykiss). Conserv Physiol 2021; 9:coab095. [PMID: 34987825 PMCID: PMC8710852 DOI: 10.1093/conphys/coab095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/16/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Anthropogenic climate change threatens freshwater biodiversity and poses a challenge for fisheries management, as fish will increasingly be exposed to episodes of high temperature and low oxygen (hypoxia). Here, we examine the extent of variation in tolerance of acute exposure to these stressors within and among five strains of rainbow trout (Oncorhynchus mykiss) currently being used or under consideration for use in stocking programmes in British Columbia, Canada. We used incipient lethal oxygen saturation (ILOS) as an index of acute hypoxia tolerance, critical thermal maximum (CTmax) as an index of acute upper thermal tolerance and mortality following these two acute exposure trials to assess the relative resilience of individuals and strains to climate change-relevant stressors. We measured tolerance across two brood years and two life stages (fry and yearling), using a highly replicated design with hundreds of individuals per strain and life stage. There was substantial within-strain variation in CTmax and ILOS, but differences among strains, although statistically significant, were small. In contrast, there were large differences in post-trial mortality among strains, ranging from less than 2% mortality in the most resilient strain to 55% mortality in the least resilient. There was a statistically significant, but weak, correlation between CTmax and ILOS at both life stages for some strains, with thermally tolerant individuals tending to be hypoxia tolerant. These data indicate that alternative metrics of tolerance may result in different conclusions regarding resilience to climate change stressors, which has important implications for stocking and management decisions for fish conservation in a changing climate.
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Affiliation(s)
- Nicholas Strowbridge
- Department of Zoology University of British Columbia, Vancouver, BC V6T 1 Z4, Canada
| | - Sara L Northrup
- Freshwater Fisheries Society of British Columbia, Abbotsford, BC V9A 7S2, Canada
| | - Madison L Earhart
- Department of Zoology University of British Columbia, Vancouver, BC V6T 1 Z4, Canada
| | - Tessa S Blanchard
- Department of Zoology University of British Columbia, Vancouver, BC V6T 1 Z4, Canada
| | - Patricia M Schulte
- Department of Zoology University of British Columbia, Vancouver, BC V6T 1 Z4, Canada
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McKenzie DJ, Zhang Y, Eliason EJ, Schulte PM, Claireaux G, Blasco FR, Nati JJH, Farrell AP. Intraspecific variation in tolerance of warming in fishes. J Fish Biol 2021; 98:1536-1555. [PMID: 33216368 DOI: 10.1111/jfb.14620] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/09/2020] [Accepted: 11/17/2020] [Indexed: 05/12/2023]
Abstract
Intraspecific variation in key traits such as tolerance of warming can have profound effects on ecological and evolutionary processes, notably responses to climate change. The empirical evidence for three primary elements of intraspecific variation in tolerance of warming in fishes is reviewed. The first is purely mechanistic that tolerance varies across life stages and as fishes become mature. The limited evidence indicates strongly that this is the case, possibly because of universal physiological principles. The second is intraspecific variation that is because of phenotypic plasticity, also a mechanistic phenomenon that buffers individuals' sensitivity to negative impacts of global warming in their lifetime, or to some extent through epigenetic effects over successive generations. Although the evidence for plasticity in tolerance to warming is extensive, more work is required to understand underlying mechanisms and to reveal whether there are general patterns. The third element is intraspecific variation based on heritable genetic differences in tolerance, which underlies local adaptation and may define long-term adaptability of a species in the face of ongoing global change. There is clear evidence of local adaptation and some evidence of heritability of tolerance to warming, but the knowledge base is limited with detailed information for only a few model or emblematic species. There is also strong evidence of structured variation in tolerance of warming within species, which may have ecological and evolutionary significance irrespective of whether it reflects plasticity or adaptation. Although the overwhelming consensus is that having broader intraspecific variation in tolerance should reduce species vulnerability to impacts of global warming, there are no sufficient data on fishes to provide insights into particular mechanisms by which this may occur.
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Affiliation(s)
- David J McKenzie
- MARBEC, University of Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Yangfan Zhang
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Guy Claireaux
- Université de Bretagne Occidentale, LEMAR (UMR 6539), Centre Ifremer de Bretagne, Plouzané, France
| | - Felipe R Blasco
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil
- Joint Graduate Program in Physiological Sciences, Federal University of São Carlos - UFSCar/São Paulo State University, UNESP Campus Araraquara, Araraquara, Brazil
| | - Julie J H Nati
- MARBEC, University of Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
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Grummer JA, Whitlock MC, Schulte PM, Taylor EB. Growth genes are implicated in the evolutionary divergence of sympatric piscivorous and insectivorous rainbow trout (Oncorhynchus mykiss). BMC Ecol Evol 2021; 21:63. [PMID: 33888062 PMCID: PMC8063319 DOI: 10.1186/s12862-021-01795-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/12/2021] [Indexed: 12/26/2022] Open
Abstract
Background Identifying ecologically significant phenotypic traits and the genomic mechanisms that underly them are crucial steps in understanding traits associated with population divergence. We used genome-wide data to identify genomic regions associated with key traits that distinguish two ecomorphs of rainbow trout (Oncorhynchus mykiss)—insectivores and piscivores—that coexist for the non-breeding portion of the year in Kootenay Lake, southeastern British Columbia. “Gerrards” are large-bodied, rapidly growing piscivores with high metabolic rates that spawn north of Kootenay Lake in the Lardeau River, in contrast to the insectivorous populations that are on average smaller in body size, with lower growth and metabolic rates, mainly forage on aquatic insects, and spawn in tributaries immediately surrounding Kootenay Lake. We used pool-seq data representing ~ 60% of the genome and 80 fish per population to assess the level of genomic divergence between ecomorphs and to identify and interrogate loci that may play functional or selective roles in their divergence. Results Genomic divergence was high between sympatric insectivores and piscivores (\documentclass[12pt]{minimal}
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\begin{document}$$F_{\text{ST}}$$\end{document}FST = 0.188), and in fact higher than between insectivorous populations from Kootenay Lake and the Blackwater River (\documentclass[12pt]{minimal}
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\begin{document}$$F_{\text{ST}}$$\end{document}FST = 0.159) that are > 500 km apart. A window-based \documentclass[12pt]{minimal}
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\begin{document}$$F_{\text{ST}}$$\end{document}FST analysis did not reveal “islands” of genomic differentiation; however, the window with highest \documentclass[12pt]{minimal}
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\begin{document}$$F_{\text{ST}}$$\end{document}FST estimate did include a gene associated with insulin secretion. Although we explored the use of the “Local score” approach to identify genomic outlier regions, this method was ultimately not used because simulations revealed a high false discovery rate (~ 20%). Gene ontology (GO) analysis identified several growth processes as enriched in genes occurring in the ~ 200 most divergent genomic windows, indicating many loci of small effect involved in growth and growth-related metabolic processes are associated with the divergence of these ecomorphs. Conclusion Our results reveal a high degree of genomic differentiation between piscivorous and insectivorous populations and indicate that the large body piscivorous phenotype is likely not due to one or a few loci of large effect. Rather, the piscivore phenotype may be controlled by several loci of small effect, thus highlighting the power of whole-genome resequencing in identifying genomic regions underlying population-level phenotypic divergences. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01795-9.
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Affiliation(s)
- Jared A Grummer
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada.
| | - Michael C Whitlock
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
| | - Patricia M Schulte
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
| | - Eric B Taylor
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada.,Beaty Biodiversity Museum, University of British Columbia, 6270 University Blvd., Vancouver, BC, V6T 1Z4, Canada
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12
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Abstract
Temperature is a critical abiotic factor shaping the distribution and abundance of species, but the mechanisms that underpin organismal thermal limits remain poorly understood. One possible mechanism underlying these limits is the failure of mitochondrial processes, as mitochondria play a crucial role in animals as the primary site of ATP production. Conventional measures of mitochondrial performance suggest that these organelles can function at temperatures much higher than those that limit whole-organism function, suggesting that they are unlikely to set organismal thermal limits. However, this conclusion is challenged by recent data connecting sequence variation in mitochondrial genes to whole-organism thermal tolerance. Here, we review the current state of knowledge of mitochondrial responses to thermal extremes and ask whether they are consistent with a role for mitochondrial function in shaping whole-organism thermal limits. The available data are fragmentary, but it is possible to draw some conclusions. There is little evidence that failure of maximal mitochondrial oxidative capacity as assessed in vitro sets thermal limits, but there is some evidence to suggest that temperature effects on ATP synthetic capacity may be important. Several studies suggest that loss of mitochondrial coupling is associated with the thermal limits for organismal growth, although this needs to be rigorously tested. Most studies have utilized isolated mitochondrial preparations to assess the effects of temperature on these organelles, and there remain many untapped opportunities to address these questions using preparations that retain more of their biological context to better connect these subcellular processes with whole-organism thermal limits.
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Affiliation(s)
- Dillon J Chung
- National Heart Lung and Blood Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20814, USA
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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13
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Sutcliffe RL, Li S, Gilbert MJH, Schulte PM, Miller KM, Farrell AP. A rapid intrinsic heart rate resetting response with thermal acclimation in rainbow trout, Oncorhynchus mykiss. J Exp Biol 2020; 223:jeb215210. [PMID: 32345705 PMCID: PMC7328139 DOI: 10.1242/jeb.215210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 04/17/2020] [Indexed: 01/01/2023]
Abstract
We examined cardiac pacemaker rate resetting in rainbow trout following a reciprocal temperature transfer. In the original experiment, performed in winter, 4°C-acclimated fish transferred to 12°C reset intrinsic heart rate after just 1 h (from 56.8±1.2 to 50.8±1.5 beats min-1); 12°C-acclimated fish transferred to 4°C reset intrinsic heart rate after 8 h (from 33.4±0.7 to 37.7±1.2 beats min-1). However, in a replicate experiment, performed in the summer using a different brood year, intrinsic heart rate was not reset, even after 10 weeks at a new temperature. Using this serendipitous opportunity, we compared mRNA expression changes of a suite of proteins in sinoatrial node (SAN), atrial and ventricular tissues after both 1 h and longer than 3 weeks for both experimental acclimation groups to identify those changes only associated with pacemaker rate resetting. Of the changes in mRNA expression occurring after more than 3 weeks of warm acclimation and associated with pacemaker rate resetting, we observed downregulation of NKA α1c in the atrium and ventricle, and upregulation of HCN1 in the ventricle. However, in the SAN there were no mRNA expression changes unique to the fish with pacemaker rate resetting after either 1 h or 3 weeks of warm acclimation. Thus, despite identifying changes in mRNA expression of contractile cardiac tissues, there was an absence of changes in mRNA expression directly involved with the initial, rapid pacemaker rate resetting with warm acclimation. Importantly, pacemaker rate resetting with thermal acclimation does not always occur in rainbow trout.
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Affiliation(s)
- Rachel L Sutcliffe
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Shaorong Li
- Pacific Biological Station, Fisheries and Oceans, Nanaimo, BC, Canada, V9T 6N7
| | - Matthew J H Gilbert
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Kristi M Miller
- Pacific Biological Station, Fisheries and Oceans, Nanaimo, BC, Canada, V9T 6N7
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
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14
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Crawford DL, Schulte PM, Whitehead A, Oleksiak MF. Evolutionary Physiology and Genomics in the Highly Adaptable Killifish (
Fundulus heteroclitus
). Compr Physiol 2020; 10:637-671. [DOI: 10.1002/cphy.c190004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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15
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Havird JC, Weaver RJ, Milani L, Ghiselli F, Greenway R, Ramsey AJ, Jimenez AG, Dowling DK, Hood WR, Montooth KL, Estes S, Schulte PM, Sokolova IM, Hill GE. Beyond the Powerhouse: Integrating Mitonuclear Evolution, Physiology, and Theory in Comparative Biology. Integr Comp Biol 2020; 59:856-863. [PMID: 31504533 DOI: 10.1093/icb/icz132] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Eukaryotes are the outcome of an ancient symbiosis and as such, eukaryotic cells fundamentally possess two genomes. As a consequence, gene products encoded by both nuclear and mitochondrial genomes must interact in an intimate and precise fashion to enable aerobic respiration in eukaryotes. This genomic architecture of eukaryotes is proposed to necessitate perpetual coevolution between the nuclear and mitochondrial genomes to maintain coadaptation, but the presence of two genomes also creates the opportunity for intracellular conflict. In the collection of papers that constitute this symposium volume, scientists working in diverse organismal systems spanning vast biological scales address emerging topics in integrative, comparative biology in light of mitonuclear interactions.
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Affiliation(s)
- Justin C Havird
- Department of Integrative Biology, University of Texas, Austin, TX 78712, USA
| | - Ryan J Weaver
- Department of Integrative Biology, University of Texas, Austin, TX 78712, USA.,Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Liliana Milani
- Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Bologna, 40126, Italy
| | - Fabrizio Ghiselli
- Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Bologna, 40126, Italy
| | - Ryan Greenway
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Adam J Ramsey
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA
| | - Ana G Jimenez
- Department of Biology, Colgate University, Hamilton, NY 13346, USA
| | - Damian K Dowling
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Kristi L Montooth
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE 68502, USA
| | - Suzanne Estes
- Department of Biology, Portland State University, Portland, OR 97201, USA
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Inna M Sokolova
- Department of Marine Biology, Institute of Biological Sciences, University of Rostock, Rostock, Germany.,Department of Maritime Systems, Interdisciplinary Faculty, University of Rostock, Rostock, Germany
| | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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16
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Giacomin M, Onukwufor JO, Schulte PM, Wood CM. Ionoregulatory aspects of the hypoxia-induced osmorespiratory compromise in the euryhaline Atlantic killifish (Fundulus heteroclitus): the effects of salinity. J Exp Biol 2020; 223:jeb.216309. [DOI: 10.1242/jeb.216309] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 05/26/2020] [Indexed: 12/20/2022]
Abstract
The osmorespiratory compromise is a physiological trade-off between the characteristics of the gill that promote respiratory gas-exchange and those that limit passive fluxes of ions and water with the environment. In hypoxia, changes in gill blood flow patterns and functional surface area that increase gas transfer can promote an exacerbation in ion and water fluxes. Our goal was to determine whether the osmorespiratory compromise is flexible, depending on environmental salinity (fresh, isosmotic and sea water) and oxygen levels (hypoxia) in euryhaline killifish, Fundulus heteroclitus. Plasma ion concentrations were minimally affected by hypoxia, indicating a maintenance of osmoregulatory homeostasis. In FW-killifish, hypoxia exposure reduced branchial Na+/K+-ATPase and NEM-sensitive-ATPase activities, as well as diffusive water flux rates. Unidirectional Na+ influx and Na+ efflux decreased during hypoxia in FW, but net Na+ flux remained unchanged. Net loss rates of Cl−, K+ and ammonia were also attenuated in hypoxia, suggesting both transcellular and paracellular reductions in permeability. These reductions appeared to be regulated phenomena as fluxes were restored immediately in normoxia. Na+ flux rates increased during hypoxia in 11 ppt, but decreased in 35 ppt, the latter suggesting a similar response to hypoxia as in FW. In summary, FW- and SW-killifish experience a reduction in gill permeability, as seen in other hypoxia-tolerant species. Fish acclimated to isosmotic salinity increased Na+ influx and efflux rates, as well as paracellular permeability in hypoxia, responses in accord with the predictions of the classic osmorespiratory compromise.
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Affiliation(s)
- Marina Giacomin
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - John O. Onukwufor
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Patricia M. Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Chris M. Wood
- Department of Zoology, The University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Biology, McMaster University, Hamilton, ON, L8S 4K1, Canada
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17
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Safi H, Zhang Y, Schulte PM, Farrell AP. The effect of acute warming and thermal acclimation on maximum heart rate of the common killifish Fundulus heteroclitus. J Fish Biol 2019; 95:1441-1446. [PMID: 31613985 DOI: 10.1111/jfb.14159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Common killifish Fundulus heteroclitus were acclimated to ecologically relevant temperatures (5, 15 and 33°C) and their maximum heart rate (fHmax ) was measured at each acclimation temperature during an acute warming protocol. Acclimation to 33°C increased peak fHmax by up to 32% and allowed the heart to beat rhythmically at a temperature 10°C higher when compared with acclimation to 5°C. Independent of acclimation temperature, peak fHmax occurred about 3°C cooler than the temperature that first produced cardiac arrhythmias. Thus, when compared with previously published values for the critical thermal maximum of F. heteroclitus, the temperature for peak fHmax was cooler and the temperature that first produced cardiac arrhythmias was similar to these critical thermal maxima. The considerable thermal plasticity of fHmax demonstrated in the present study is entirely consistent with eurythermal ecology of killifish, as shown previously for another eurythermal fish Gillichthys mirabilis.
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Affiliation(s)
- Hamid Safi
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yangfan Zhang
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anthony P Farrell
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, Canada
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18
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Giacomin M, Bryant HJ, Val AL, Schulte PM, Wood CM. The osmorespiratory compromise: physiological responses and tolerance to hypoxia are affected by salinity acclimation in the euryhaline Atlantic killifish ( Fundulus heteroclitus). ACTA ACUST UNITED AC 2019; 222:jeb.206599. [PMID: 31488621 DOI: 10.1242/jeb.206599] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 09/03/2019] [Indexed: 12/16/2022]
Abstract
The characteristics of the fish gill that maximize gas exchange are the same that promote diffusion of ions and water to and from the environment; therefore, physiological trade-offs are likely to occur. Here, we investigated how salinity acclimation affects whole-animal respiratory gas exchange during hypoxia using Fundulus heteroclitus, a fish that inhabits salt marshes where salinity and oxygen levels vary greatly. Salinity had marked effects on hypoxia tolerance, with fish acclimated to 11 and 35 ppt showing much longer time to loss of equilibrium (LOE) in hypoxia than 0 ppt-acclimated fish. Fish acclimated to 11 ppt (isosmotic salinity) exhibited the greatest capacity to regulate oxygen consumption rate (Ṁ O2 ) under hypoxia, as measured through the regulation index (RI) and P crit At 35 ppt, fish had a higher routine metabolic rate (RMR) but a lower RI than fish at 11 ppt, but there were no differences in gill morphology, ventilation or blood O2 transport properties between these groups. In contrast, 0 ppt-acclimated fish had the highest ventilation and lowest O2 extraction efficiency in normoxia and hypoxia, indicating a higher ventilatory workload in order to maintain similar levels of Ṁ O2 These differences were related to alterations in gill morphology, where 0 ppt-acclimated fish had the smallest lamellar surface area with the greatest epithelial cell coverage (i.e. thicker lamellae, longer diffusion distance) and a larger interlamellar cell mass, contrasting with 11 ppt-acclimated fish, which had overall the highest respiratory surface area. The alteration of an array of physiological parameters provides evidence for a compromise between salinity and hypoxia tolerance in killifish acclimated to freshwater.
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Affiliation(s)
- Marina Giacomin
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4 .,Bamfield Marine Sciences Centre, Bamfield, BC, Canada V0R 1B0
| | - Heather J Bryant
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Adalberto L Val
- Laboratory of Ecophysiology and Molecular Evolution, Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas 69080-971, Brazil
| | - Patricia M Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Chris M Wood
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada V6T 1Z4.,Bamfield Marine Sciences Centre, Bamfield, BC, Canada V0R 1B0.,Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
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19
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McKenzie JL, Chung DJ, Healy TM, Brennan RS, Bryant HJ, Whitehead A, Schulte PM. Mitochondrial Ecophysiology: Assessing the Evolutionary Forces That Shape Mitochondrial Variation. Integr Comp Biol 2019; 59:925-937. [PMID: 31282925 DOI: 10.1093/icb/icz124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The mitonuclear species concept hypothesizes that incompatibilities between interacting gene products of the nuclear and mitochondrial genomes are a major factor establishing and maintaining species boundaries. However, most of the data available to test this concept come from studies of genetic variation in mitochondrial DNA, and clines in the mitochondrial genome across contact zones can be produced by a variety of forces. Here, we show that using a combination of population genomic analyses of the nuclear and mitochondrial genomes and studies of mitochondrial function can provide insight into the relative roles of neutral processes, adaptive evolution, and mitonuclear incompatibility in establishing and maintaining mitochondrial clines, using Atlantic killifish (Fundulus heteroclitus) as a case study. There is strong evidence for a role of secondary contact following the last glaciation in shaping a steep mitochondrial cline across a contact zone between northern and southern subspecies of killifish, but there is also evidence for a role of adaptive evolution in driving differentiation between the subspecies in a variety of traits from the level of the whole organism to the level of mitochondrial function. In addition, studies are beginning to address the potential for mitonuclear incompatibilities in admixed populations. However, population genomic studies have failed to detect evidence for a strong and pervasive influence of mitonuclear incompatibilities, and we suggest that polygenic selection may be responsible for the complex patterns observed. This case study demonstrates that multiple forces can act together in shaping mitochondrial clines, and illustrates the challenge of disentangling their relative roles.
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Affiliation(s)
- Jessica L McKenzie
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Dillon J Chung
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Timothy M Healy
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Reid S Brennan
- Department of Environmental Toxicology, University of California-Davis, 4138 Meyer Hall, 1 Shields Avenue, Davis, CA 95616, USA
| | - Heather J Bryant
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Andrew Whitehead
- Department of Environmental Toxicology, University of California-Davis, 4138 Meyer Hall, 1 Shields Avenue, Davis, CA 95616, USA
| | - Patricia M Schulte
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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20
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Healy TM, Brennan RS, Whitehead A, Schulte PM. Mitochondria, sex and variation in routine metabolic rate. Mol Ecol 2019; 28:4608-4619. [PMID: 31529542 DOI: 10.1111/mec.15244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/12/2019] [Indexed: 12/14/2022]
Abstract
Variation in the metabolic costs associated with organismal maintenance may play a key role in determining fitness, and thus these differences among individuals are likely to be subject to natural selection. Although the evolvability of maintenance metabolism depends on its underlying genetic architecture, relatively little is known about the nature of genetic variation that underlies this trait. To address this, we measured variation in routine metabolic rate (ṀO2 routine ), an index of maintenance metabolism, within and among three populations of Atlantic killifish, Fundulus heteroclitus, including a population from a region of genetic admixture between two subspecies. Polygenic association tests among individuals from the admixed population identified 54 single nucleotide polymorphisms (SNPs) that were associated with ṀO2 routine , and these SNPs accounted for 43% of interindividual variation in this trait. However, genetic associations with ṀO2 routine involved different SNPs if females and males were analysed separately, and there was a sex-dependent effect of mitochondrial genotype on variation in routine metabolism. These results imply that there are sex-specific genetic mechanisms, and potential mitonuclear interactions, that underlie variation in ṀO2 routine . Additionally, there was evidence for epistatic interactions between 17% of the possible pairs of trait-associated SNPs, suggesting that epistatic effects on ṀO2 routine are common. These data demonstrate not only that phenotypic variation in this ecologically important trait has a polygenic basis with considerable epistasis among loci, but also that these underlying genetic mechanisms, and particularly the role of mitochondrial genotype, may be sex-specific.
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Affiliation(s)
- Timothy M Healy
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Reid S Brennan
- Department of Environmental Toxicology, University of California Davis, Davis, CA, USA
| | - Andrew Whitehead
- Department of Environmental Toxicology, University of California Davis, Davis, CA, USA
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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21
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Weir LK, Barker MK, McDonnell LM, Schimpf NG, Rodela TM, Schulte PM. Small changes, big gains: A curriculum-wide study of teaching practices and student learning in undergraduate biology. PLoS One 2019; 14:e0220900. [PMID: 31461447 PMCID: PMC6713325 DOI: 10.1371/journal.pone.0220900] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/25/2019] [Indexed: 11/18/2022] Open
Abstract
A growing body of evidence has shown that active learning has a considerable advantage over traditional lecture for student learning in undergraduate STEM classes, but there have been few large-scale studies to identify the specific types of activities that have the greatest impact on learning. We therefore undertook a large-scale, curriculum-wide study to investigate the effects of time spent on a variety of classroom activities on learning gains. We quantified classroom practices and related these to student learning, assessed using diagnostic tests written by over 3700 students, across 31 undergraduate biology classes at a research-intensive university in the Pacific Northwest. The most significant positive predictor of learning gains was the use of group work, supporting the findings of previous studies. Strikingly, we found that the addition of worksheets as an active learning tool for in-class group activities had the strongest impact on diagnostic test scores. This particular low-tech activity promotes student collaboration, develops problem solving skills, and can be used to inform the instructor about what students are struggling with, thus providing opportunities for valuable and timely feedback. Overall, our results indicate that group activities with low barriers to entry, such as worksheets, can result in significant learning gains in undergraduate science.
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Affiliation(s)
- Laura K. Weir
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
| | - Megan K. Barker
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa M. McDonnell
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
| | - Natalie G. Schimpf
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tamara M. Rodela
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
| | - Patricia M. Schulte
- Carl Wieman Science Education Initiative, University of British Columbia, Vancouver, British Columbia, Canada
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22
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Brady SP, Bolnick DI, Barrett RDH, Chapman L, Crispo E, Derry AM, Eckert CG, Fraser DJ, Fussmann GF, Gonzalez A, Guichard F, Lamy T, Lane J, McAdam AG, Newman AEM, Paccard A, Robertson B, Rolshausen G, Schulte PM, Simons AM, Vellend M, Hendry A. Understanding Maladaptation by Uniting Ecological and Evolutionary Perspectives. Am Nat 2019; 194:495-515. [PMID: 31490718 DOI: 10.1086/705020] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Evolutionary biologists have long trained their sights on adaptation, focusing on the power of natural selection to produce relative fitness advantages while often ignoring changes in absolute fitness. Ecologists generally have taken a different tack, focusing on changes in abundance and ranges that reflect absolute fitness while often ignoring relative fitness. Uniting these perspectives, we articulate various causes of relative and absolute maladaptation and review numerous examples of their occurrence. This review indicates that maladaptation is reasonably common from both perspectives, yet often in contrasting ways. That is, maladaptation can appear strong from a relative fitness perspective, yet populations can be growing in abundance. Conversely, resident individuals can appear locally adapted (relative to nonresident individuals) yet be declining in abundance. Understanding and interpreting these disconnects between relative and absolute maladaptation, as well as the cases of agreement, is increasingly critical in the face of accelerating human-mediated environmental change. We therefore present a framework for studying maladaptation, focusing in particular on the relationship between absolute and relative fitness, thereby drawing together evolutionary and ecological perspectives. The unification of these ecological and evolutionary perspectives has the potential to bring together previously disjunct research areas while addressing key conceptual issues and specific practical problems.
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23
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Brennan RS, Healy TM, Bryant HJ, La MV, Schulte PM, Whitehead A. Integrative Population and Physiological Genomics Reveals Mechanisms of Adaptation in Killifish. Mol Biol Evol 2019; 35:2639-2653. [PMID: 30102365 DOI: 10.1093/molbev/msy154] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Adaptive divergence between marine and freshwater (FW) environments is important in generating phyletic diversity within fishes, but the genetic basis of this process remains poorly understood. Genome selection scans can identify adaptive loci, but incomplete knowledge of genotype-phenotype connections makes interpreting their significance difficult. In contrast, association mapping (genome-wide association mapping [GWAS], random forest [RF] analyses) links genotype to phenotype, but offer limited insight into the evolutionary forces shaping variation. Here, we combined GWAS, RF, and selection scans to identify loci important in adaptation to FW environments. We utilized FW-native and brackish water (BW)-native populations of Atlantic killifish (Fundulus heteroclitus) as well as a naturally admixed population between the two. We measured morphology and multiple physiological traits that differ between populations and may contribute to osmotic adaptation (salinity tolerance, hypoxia tolerance, metabolic rate, body shape) and used a reduced representation approach for genome-wide genotyping. Our results show patterns of population divergence in physiological capabilities that are consistent with local adaptation. Population genomic scans between BW-native and FW-native populations identified genomic regions evolving by natural selection, whereas association mapping revealed loci that contribute to variation for each trait. There was substantial overlap in the genomic regions putatively under selection and loci associated with phenotypic traits, particularly for salinity tolerance, suggesting that these regions and genes are important for adaptive divergence between BW and FW environments. Together, these data provide insight into the mechanisms that enable diversification of fishes across osmotic boundaries.
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Affiliation(s)
- Reid S Brennan
- Department of Environmental Toxicology, University of California-Davis, Davis, CA.,Department of Biology, University of Vermont, Burlington, VT
| | - Timothy M Healy
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada.,Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, CA
| | - Heather J Bryant
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Man Van La
- Department of Environmental Toxicology, University of California-Davis, Davis, CA
| | - Patricia M Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada
| | - Andrew Whitehead
- Department of Environmental Toxicology, University of California-Davis, Davis, CA
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24
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Regan MD, Mandic M, Dhillon RS, Lau GY, Farrell AP, Schulte PM, Seibel BA, Speers-Roesch B, Ultsch GR, Richards JG. Don't throw the fish out with the respirometry water. J Exp Biol 2019; 222:222/6/jeb200253. [DOI: 10.1242/jeb.200253] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Matthew D. Regan
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Milica Mandic
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 6N5
| | - Rashpal S. Dhillon
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Gigi Y. Lau
- Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
| | - Anthony P. Farrell
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Brad A. Seibel
- College of Marine Science, University of South Florida, St Petersburg, FL 33701, USA
| | - Ben Speers-Roesch
- Department of Biological Sciences, University of New Brunswick-Saint John, PO Box 5050, Saint John, NB, Canada, E2L 4L5
| | - Gordon R. Ultsch
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Jeffrey G. Richards
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
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25
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Giacomin M, Dal Pont G, Eom J, Schulte PM, Wood CM. The effects of salinity and hypoxia exposure on oxygen consumption, ventilation, diffusive water exchange and ionoregulation in the Pacific hagfish (Eptatretus stoutii). Comp Biochem Physiol A Mol Integr Physiol 2019; 232:47-59. [PMID: 30878760 DOI: 10.1016/j.cbpa.2019.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/30/2019] [Accepted: 03/06/2019] [Indexed: 10/27/2022]
Abstract
Hagfishes (Class: Myxini) are marine jawless craniate fishes that are widely considered to be osmoconformers whose plasma [Na+], [Cl-] and osmolality closely resemble that of sea water, although they have the ability to regulate plasma [Ca2+] and [Mg2+] below seawater levels. We investigated the responses of Pacific hagfish to changes in respiratory and ionoregulatory demands imposed by a 48-h exposure to altered salinity (25 ppt, 30 ppt (control) and 35 ppt) and by an acute hypoxia exposure (30 Torr; 4 kPa). When hagfish were exposed to 25 ppt, oxygen consumption rate (MO2), ammonia excretion rate (Jamm) and unidirectional diffusive water flux rate (JH2O, measured with 3H2O) were all reduced, pointing to an interaction between ionoregulation and gas exchange. At 35 ppt, JH2O was reduced, though MO2 and Jamm did not change. As salinity increased, so did the difference between plasma and external water [Ca2+] and [Mg2+]. Notably, the same pattern was seen for plasma Cl-, which was kept below seawater [Cl-] at all salinities, while plasma [Na+] was regulated well above seawater [Na+], but plasma osmolality matched seawater values. MO2 was reduced by 49% and JH2O by 36% during hypoxia, despite a small elevation in overall ventilation. Our results depart from the "classical" osmorespiratory compromise but are in accord with responses in other hypoxia-tolerant fish; instead of an exacerbation of gill fluxes when gas transfer is upregulated, the opposite happens.
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Affiliation(s)
- Marina Giacomin
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada.
| | - Giorgi Dal Pont
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Integrated Group for Aquaculture and Environmental Studies, Department of Animal Science, Federal University of Paraná, Curitiba, Paraná 83035-050, Brazil
| | - Junho Eom
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada.
| | - Patricia M Schulte
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Chris M Wood
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia V0R 1B0, Canada; Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
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26
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Hood WR, Austad SN, Bize P, Jimenez AG, Montooth KL, Schulte PM, Scott GR, Sokolova I, Treberg JR, Salin K. The Mitochondrial Contribution to Animal Performance, Adaptation, and Life-History Variation. Integr Comp Biol 2019; 58:480-485. [PMID: 30239783 PMCID: PMC8502431 DOI: 10.1093/icb/icy089] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Animals display tremendous variation in their rates of growth, reproductive output, and longevity. While the physiological and molecular mechanisms that underlie this variation remain poorly understood, the performance of the mitochondrion has emerged as a key player. Mitochondria not only impact the performance of eukaryotes via their capacity to produce ATP, but they also play a role in producing heat and reactive oxygen species and function as a major signaling hub for the cell. The papers included in this special issue emerged from a symposium titled "Inside the Black Box: The Mitochondrial Basis of Life-history Variation and Animal Performance." Based on studies of diverse animal taxa, three distinct themes emerged from these papers. (1) When linking mitochondrial function to components of fitness, it is crucial that mitochondrial assays are performed in conditions as close as the intracellular conditions experienced by the mitochondria in vivo. (2) Functional plasticity allows mitochondria to retain their performance, as well as that of their host, over a range of exogenous conditions, and selection on mitochondrial and nuclear-derived proteins can optimize the match between the environment and the bioenergetic capacity of the mitochondrion. Finally, (3) studies of wild and wild-derived animals suggest that mitochondria play a central role in animal performance and life history strategy. Taken as a whole, we hope that these papers will foster discussion and inspire new hypotheses and innovations that will further our understanding of the mitochondrial processes that underlie variation in life history traits and animal performance.
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Affiliation(s)
- Wendy R Hood
- Department of Biological Sciences, Auburn University, AL 36849, USA
| | - Steven N Austad
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35294-1170, USA
| | - Pierre Bize
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK
| | - Ana Gabriela Jimenez
- Department of Biology, Colgate University, 13 Oak Drive, Hamilton, NY 13346, USA
| | - Kristi L Montooth
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Graham R Scott
- Department of Biology, McMaster University, Hamilton, Ontario, Canada L8S 4K1
| | - Inna Sokolova
- Department of Marine Biology, Institute for Biological Sciences, University of Rostock, Rostock 18055, Germany.,Department of the Maritime Systems, Interdisciplinary Faculty, University of Rostock, Rostock 18055, Germany
| | - Jason R Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.,Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.,Centre on Aging, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Karine Salin
- Ifremer, Unité de Physiologie Fonctionnelle des Organismes Marins-LEMAR UMR 6530, Plouzané 29280, France
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27
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Healy TM, Schulte PM. Patterns of alternative splicing in response to cold acclimation in fish. ACTA ACUST UNITED AC 2019; 222:jeb.193516. [PMID: 30692167 DOI: 10.1242/jeb.193516] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/23/2019] [Indexed: 12/26/2022]
Abstract
Phenotypic plasticity is an important aspect of an organism's response to environmental change that often requires the modulation of gene expression. These changes in gene expression can be quantitative, as a result of increases or decreases in the amounts of specific transcripts, or qualitative, as a result of the expression of alternative transcripts from the same gene (e.g. via alternative splicing of pre-mRNAs). Although the role of quantitative changes in gene expression in phenotypic plasticity is well known, relatively few studies have examined the role of qualitative changes. Here, we use skeletal muscle RNA-seq data from Atlantic killifish (Fundulus heteroclitus), threespine stickleback (Gasterosteus aculeatus) and zebrafish (Danio rerio) to investigate the extent of qualitative changes in gene expression in response to cold acclimation. Fewer genes demonstrated alternative splicing than differential expression as a result of cold acclimation; however, differences in splicing were detected for 426 to 866 genes depending on species, indicating that large numbers of qualitative changes in gene expression are associated with cold acclimation. Many of these alternatively spliced genes were also differentially expressed, and there was functional enrichment for involvement in muscle contraction among the genes demonstrating qualitative changes in response to cold acclimation. Additionally, there was a common group of 29 genes with cold-acclimation-mediated changes in splicing in all three species, suggesting that there may be a set of genes with expression patterns that respond qualitatively to prolonged exposure to cold temperatures across fishes.
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Affiliation(s)
- Timothy M Healy
- The University of British Columbia, Department of Zoology, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
| | - Patricia M Schulte
- The University of British Columbia, Department of Zoology, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
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28
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Giacomin M, Eom J, Schulte PM, Wood CM. Acute temperature effects on metabolic rate, ventilation, diffusive water exchange, osmoregulation, and acid–base status in the Pacific hagfish (Eptatretus stoutii). J Comp Physiol B 2018; 189:17-35. [DOI: 10.1007/s00360-018-1191-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 12/21/2022]
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29
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Healy TM, Brennan RS, Whitehead A, Schulte PM. Tolerance traits related to climate change resilience are independent and polygenic. Glob Chang Biol 2018; 24:5348-5360. [PMID: 29995321 DOI: 10.1111/gcb.14386] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 06/06/2018] [Indexed: 05/21/2023]
Abstract
The resilience of organisms to climate change through adaptive evolution is dependent on the extent of genetically based variation in key phenotypic traits and the nature of genetic associations between them. For aquatic animals, upper thermal tolerance and hypoxia tolerance are likely to be a important determinants of sensitivity to climate change. To determine the genetic basis of these traits and to detect associations between them, we compared naturally occurring populations of two subspecies of Atlantic killifish, Fundulus heteroclitus, that differ in both thermal and hypoxia tolerance. Multilocus association mapping demonstrated that 47 and 35 single nucleotide polymorphisms (SNPs) explained 43.4% and 51.9% of variation in thermal and hypoxia tolerance, respectively, suggesting that genetic mechanisms underlie a substantial proportion of variation in each trait. However, no explanatory SNPs were shared between traits, and upper thermal tolerance varied approximately linearly with latitude, whereas hypoxia tolerance exhibited a steep phenotypic break across the contact zone between the subspecies. These results suggest that upper thermal tolerance and hypoxia tolerance are neither phenotypically correlated nor genetically associated, and thus that rates of adaptive change in these traits can be independently fine-tuned by natural selection. This modularity of important traits can underpin the evolvability of organisms to complex future environmental change.
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Affiliation(s)
- Timothy M Healy
- The University of British Columbia, Department of Zoology, Vancouver, British Columbia, Canada
| | - Reid S Brennan
- Department of Environmental Toxicology, University of California-Davis, Davis, California
| | - Andrew Whitehead
- Department of Environmental Toxicology, University of California-Davis, Davis, California
| | - Patricia M Schulte
- The University of British Columbia, Department of Zoology, Vancouver, British Columbia, Canada
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Metzger DCH, Schulte PM. The DNA Methylation Landscape of Stickleback Reveals Patterns of Sex Chromosome Evolution and Effects of Environmental Salinity. Genome Biol Evol 2018; 10:775-785. [PMID: 29420714 PMCID: PMC5841383 DOI: 10.1093/gbe/evy034] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2018] [Indexed: 12/12/2022] Open
Abstract
Epigenetic mechanisms such as DNA methylation are a key component of dosage compensation on sex chromosomes and have been proposed as an important source of phenotypic variation influencing plasticity and adaptive evolutionary processes, yet little is known about the role of DNA methylation in an ecological or evolutionary context in vertebrates. The threespine stickleback (Gasterosteus aculeatus) is an ecological and evolutionary model system that has been used to study mechanisms involved in the evolution of adaptive phenotypes in novel environments as well as the evolution heteromorphic sex chromosomes and dosage compensation in vertebrates. Using whole genome bisulfite sequencing, we compared genome-wide DNA methylation patterns between threespine stickleback males and females and between stickleback reared at different environmental salinities. Apparent hypermethylation of the younger evolutionary stratum of the stickleback X chromosome in females relative to males suggests a potential role of DNA methylation in the evolution of heteromorphic sex chromosomes. We also demonstrate that rearing salinity has genome-wide effects on DNA methylation levels, which has the potential to lead to the accumulation of epigenetic variation between natural populations in different environments.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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31
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Schulte PM, Hall JG. ECHOES ACROSS GENERATIONS. Memory 2018. [DOI: 10.2307/j.ctvbtzpfm.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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32
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Gibbons TC, McBryan TL, Schulte PM. Interactive effects of salinity and temperature acclimation on gill morphology and gene expression in threespine stickleback. Comp Biochem Physiol A Mol Integr Physiol 2018; 221:55-62. [DOI: 10.1016/j.cbpa.2018.03.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 03/16/2018] [Accepted: 03/21/2018] [Indexed: 02/08/2023]
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33
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Metzger DCH, Schulte PM. Persistent and plastic effects of temperature on DNA methylation across the genome of threespine stickleback ( Gasterosteus aculeatus). Proc Biol Sci 2018; 284:rspb.2017.1667. [PMID: 28978736 DOI: 10.1098/rspb.2017.1667] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 08/31/2017] [Indexed: 12/27/2022] Open
Abstract
Epigenetic mechanisms such as changes in DNA methylation have the potential to affect the resilience of species to climate change, but little is known about the response of the methylome to changes in environmental temperature in animals. Using reduced representation bisulfite sequencing, we assessed the effects of development temperature and adult acclimation temperature on DNA methylation levels in threespine stickleback (Gasterosteus aculeatus). Across all treatments, we identified 2130 differentially methylated cytosines distributed across the genome. Both increases and decreases in temperature during development and with thermal acclimation in adults increased global DNA methylation levels. Approximately 25% of the differentially methylated regions (DMRs) responded to both developmental temperature and adult thermal acclimation, and 50 DMRs were common to all treatments, demonstrating a core response of the epigenome to thermal change at multiple time scales. We also identified differentially methylated loci that were specific to a particular developmental or adult thermal response, which could facilitate the accumulation of epigenetic variation between natural populations that experience different thermal regimes. These data demonstrate that thermal history can have long-lasting effects on the epigenome, highlighting the role of epigenetic modifications in the response to temperature change across multiple time scales.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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Chung DJ, Healy TM, McKenzie JL, Chicco AJ, Sparagna GC, Schulte PM. Mitochondria, Temperature, and the Pace of Life. Integr Comp Biol 2018; 58:578-590. [DOI: 10.1093/icb/icy013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Dillon J Chung
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Timothy M Healy
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, CA 92037, USA
| | - Jessica L McKenzie
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Adam J Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1680, USA
| | - Genevieve C Sparagna
- Anschutz Medical Campus, Division of Cardiology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Patricia M Schulte
- Department of Zoology and Biodiversity Research Centre, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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35
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Metzger DCH, Schulte PM. Similarities in temperature-dependent gene expression plasticity across timescales in threespine stickleback (Gasterosteus aculeatus). Mol Ecol 2018; 27:2381-2396. [PMID: 29654710 DOI: 10.1111/mec.14591] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/16/2018] [Accepted: 03/26/2018] [Indexed: 12/22/2022]
Abstract
Phenotypic plasticity occurs at a variety of timescales, but little is known about the degree to which plastic responses at different timescales are associated with similar underlying molecular processes, which is critical for assessing the effects of plasticity on evolutionary trajectories. To address this issue, we identified differential gene expression in response to developmental temperature in the muscle transcriptome of adult threespine stickleback (Gasterosteus aculeatus) exposed to 12, 18 and 24°C until hatch and then held at 18°C for 9 months and compared these results to differential gene expression in response to adult thermal acclimation in stickleback developed at 18°C and then acclimated to 5 and 25°C as adults. Adult thermal acclimation affected the expression of 7,940 and 7,015 genes in response to cold and warm acclimation, respectively, and 4,851 of these genes responded in both treatments. In contrast, the expression of only 33 and 29 genes was affected by cold and warm development, respectively. The majority of the genes affected by developmental temperature were also affected by adult acclimation temperature. Many genes that were differentially expressed as a result of adult acclimation were associated with previously identified temperature-dependent effects on DNA methylation patterns, suggesting a role of epigenetic mechanisms in regulating gene expression plasticity during acclimation. Taken together, these results demonstrate similarities between the persistent effects of developmental plasticity on gene expression and the effects of adult thermal acclimation, emphasizing the potential for mechanistic links between plasticity acting at these different life stages.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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36
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Chung DJ, Sparagna GC, Chicco AJ, Schulte PM. Patterns of mitochondrial membrane remodeling parallel functional adaptations to thermal stress. J Exp Biol 2018; 221:221/7/jeb174458. [DOI: 10.1242/jeb.174458] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/14/2018] [Indexed: 01/07/2023]
Abstract
ABSTRACT
The effect of temperature on mitochondrial performance is thought to be partly due to its effect on mitochondrial membranes. Numerous studies have shown that thermal acclimation and adaptation can alter the amount of inner-mitochondrial membrane (IMM), but little is known about the capacity of organisms to modulate mitochondrial membrane composition. Using northern and southern subspecies of Atlantic killifish (Fundulus heteroclitus) that are locally adapted to different environmental temperatures, we assessed whether thermal acclimation altered liver mitochondrial respiratory capacity or the composition and amount of IMM. We measured changes in phospholipid headgroups and headgroup-specific fatty acid (FA) remodeling, and used respirometry to assess mitochondrial respiratory capacity. Acclimation to 5°C and 33°C altered mitochondrial respiratory capacity in both subspecies. Northern F. heteroclitus exhibited greater mitochondrial respiratory capacity across acclimation temperatures, consistent with previously observed subspecies differences in whole-organism aerobic metabolism. Mitochondrial phospholipids were altered following thermal acclimation, and the direction of these changes was largely consistent between subspecies. These effects were primarily driven by remodeling of specific phospholipid classes and were associated with shifts in metabolic phenotypes. There were also differences in membrane composition between subspecies that were driven largely by differences in phospholipid classes. Changes in respiratory capacity between subspecies and with acclimation were largely but not completely accounted for by alterations in the amount of IMM. Taken together, these results support a role for changes in liver mitochondrial function in the ectothermic response to thermal stress during both acclimation and adaptation, and implicate lipid remodeling as a mechanism contributing to these changes.
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Affiliation(s)
- Dillon J. Chung
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Genevieve C. Sparagna
- Department of Medicine/Division of Cardiology, University of Colorado Anschutz Medical Center, Aurora, CO 80045, USA
| | - Adam J. Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1680, USA
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
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37
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Stains M, Harshman J, Barker MK, Chasteen SV, Cole R, DeChenne-Peters SE, Eagan MK, Esson JM, Knight JK, Laski FA, Levis-Fitzgerald M, Lee CJ, Lo SM, McDonnell LM, McKay TA, Michelotti N, Musgrove A, Palmer MS, Plank KM, Rodela TM, Sanders ER, Schimpf NG, Schulte PM, Smith MK, Stetzer M, Van Valkenburgh B, Vinson E, Weir LK, Wendel PJ, Wheeler LB, Young AM. Anatomy of STEM teaching in North American universities. Science 2018; 359:1468-1470. [PMID: 29599232 PMCID: PMC6310123 DOI: 10.1126/science.aap8892] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
National and local initiatives focused on the transformation of STEM teaching in higher education have multiplied over the last decade. These initiatives often focus on measuring change in instructional practices, but it is difficult to monitor such change without a national picture of STEM educational practices, especially as characterized by common observational instruments. We characterized a snapshot of this landscape by conducting the first large scale observation-based study. We found that lecturing was prominent throughout the undergraduate STEM curriculum, even in classrooms with infrastructure designed to support active learning, indicating that further work is required to reform STEM education. Additionally, we established that STEM faculty’s instructional practices can vary substantially within a course, invalidating the commonly-used teaching evaluations based on a one-time observation. Although lecture is prominent throughout the undergraduate STEM curriculum, STEM faculty employ varied teaching practices within the same course.
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Affiliation(s)
- M Stains
- The list of author affiliations is provided in the supplementary materials.
| | - J Harshman
- The list of author affiliations is provided in the supplementary materials
| | - M K Barker
- The list of author affiliations is provided in the supplementary materials
| | - S V Chasteen
- The list of author affiliations is provided in the supplementary materials
| | - R Cole
- The list of author affiliations is provided in the supplementary materials
| | | | - M K Eagan
- The list of author affiliations is provided in the supplementary materials
| | - J M Esson
- The list of author affiliations is provided in the supplementary materials
| | - J K Knight
- The list of author affiliations is provided in the supplementary materials
| | - F A Laski
- The list of author affiliations is provided in the supplementary materials
| | - M Levis-Fitzgerald
- The list of author affiliations is provided in the supplementary materials
| | - C J Lee
- The list of author affiliations is provided in the supplementary materials
| | - S M Lo
- The list of author affiliations is provided in the supplementary materials
| | - L M McDonnell
- The list of author affiliations is provided in the supplementary materials
| | - T A McKay
- The list of author affiliations is provided in the supplementary materials
| | - N Michelotti
- The list of author affiliations is provided in the supplementary materials
| | - A Musgrove
- The list of author affiliations is provided in the supplementary materials
| | - M S Palmer
- The list of author affiliations is provided in the supplementary materials
| | - K M Plank
- The list of author affiliations is provided in the supplementary materials
| | - T M Rodela
- The list of author affiliations is provided in the supplementary materials
| | - E R Sanders
- The list of author affiliations is provided in the supplementary materials
| | - N G Schimpf
- The list of author affiliations is provided in the supplementary materials
| | - P M Schulte
- The list of author affiliations is provided in the supplementary materials
| | - M K Smith
- The list of author affiliations is provided in the supplementary materials
| | - M Stetzer
- The list of author affiliations is provided in the supplementary materials
| | - B Van Valkenburgh
- The list of author affiliations is provided in the supplementary materials
| | - E Vinson
- The list of author affiliations is provided in the supplementary materials
| | - L K Weir
- The list of author affiliations is provided in the supplementary materials
| | - P J Wendel
- The list of author affiliations is provided in the supplementary materials
| | - L B Wheeler
- The list of author affiliations is provided in the supplementary materials
| | - A M Young
- The list of author affiliations is provided in the supplementary materials
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38
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Zhang Y, Healy TM, Vandersteen W, Schulte PM, Farrell AP. A rainbow trout Oncorhynchus mykiss strain with higher aerobic scope in normoxia also has superior tolerance of hypoxia. J Fish Biol 2018; 92:487-503. [PMID: 29431223 DOI: 10.1111/jfb.13530] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/05/2017] [Indexed: 06/08/2023]
Abstract
This study compared parr from three strains of rainbow trout Oncorhynchus mykiss to examine intraspecific variation in metabolic traits, hypoxia tolerance and upper thermal tolerance in this species. At the strain level, variation in absolute aerobic scope (AAS), critical oxygen level (O2crit ), incipient lethal oxygen saturation (ILOS) and critical thermal maximum (CTmax ) generally exhibited consistent differences among the strains, suggesting the possibility of functional associations among these traits. This possibility was further supported at the individual level by a positive correlation between ILOS and O2crit and a negative correlation between O2crit and AAS. These results indicate that intraspecific differences in hypoxia tolerance among strains of O. mykiss may be primarily determined by differences in the ability to maintain oxygen uptake in hypoxia and that variation in aerobic scope in normoxia probably plays a role in determining the ability of these fish to sustain metabolism aerobically as water oxygen saturation is reduced.
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Affiliation(s)
- Y Zhang
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - T M Healy
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - W Vandersteen
- Miracle Springs Inc., Fraser Valley, British Columbia V2V 0A6, Canada
| | - P M Schulte
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - A P Farrell
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Marshall WS, Breves JP, Doohan EM, Tipsmark CK, Kelly SP, Robertson GN, Schulte PM. claudin-10 isoform expression and cation selectivity change with salinity in salt-secreting epithelia of Fundulusheteroclitus. ACTA ACUST UNITED AC 2018; 221:jeb.168906. [PMID: 29150449 DOI: 10.1242/jeb.168906] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 11/13/2017] [Indexed: 12/11/2022]
Abstract
To provide insight into claudin (Cldn) tight junction (TJ) protein contributions to branchial salt secretion in marine teleost fishes, this study examined cldn-10 TJ protein isoforms of a euryhaline teleost (mummichog; Fundulus heteroclitus) in association with salinity change and measurements of transepithelial cation selectivity. Mummichogs were transferred from freshwater (FW) to seawater (SW, 35‰) and from SW to hypersaline SW (2SW, 60‰) in a time course with transfer control groups (FW to FW, and SW to SW). FW to SW transfer increased mRNA abundance of cldn-10d and cldn-10e twofold, whilst cldn-10c and cldn-10f transcripts were unchanged. Transfer from SW to 2SW did not alter cldn-10d, and transiently altered cldn-10e abundance, but increased cldn-10c and cldn-10f fourfold. This was coincident with an increased number of single-stranded junctions (observed by transmission electron microscopy). For both salinity transfers, (1) cldn-10e mRNA was acutely responsive (i.e. after 24 h), (2) other responsive cldn-10 isoforms increased later (3-7 days), and (3) cystic fibrosis transmembrane conductance regulator (cftr) mRNA was elevated in accordance with established changes in transcellular Cl- movement. Changes in mRNA encoding cldn-10c and -10f appeared linked, consistent with the tandem repeat locus in the Fundulus genome, whereas mRNA for tandem cldn-10d and cldn-10e seemed independent of each other. Cation selectivity sequence measured by voltage and conductance responses to artificial SW revealed Eisenman sequence VII: Na+>K+>Rb+∼Cs+>Li+ Collectively, these data support the idea that Cldn-10 TJ proteins create and maintain cation-selective pore junctions in salt-secreting tissues of teleost fishes.
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Affiliation(s)
- William S Marshall
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Jason P Breves
- Department of Biology, Skidmore College, Saratoga Springs, NY 12866, USA
| | - Ellen M Doohan
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Christian K Tipsmark
- Department of Biological Sciences, University of Arkansas, Fayetteville, AK 72701, USA
| | - Scott P Kelly
- Department of Biology, York University, Toronto, ON, Canada M3J 1P3
| | - George N Robertson
- Department of Biology, St Francis Xavier University, Antigonish, NS, Canada B2G 2W5
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
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Jutfelt F, Norin T, Ern R, Overgaard J, Wang T, McKenzie DJ, Lefevre S, Nilsson GE, Metcalfe NB, Hickey AJR, Brijs J, Speers-Roesch B, Roche DG, Gamperl AK, Raby GD, Morgan R, Esbaugh AJ, Gräns A, Axelsson M, Ekström A, Sandblom E, Binning SA, Hicks JW, Seebacher F, Jørgensen C, Killen SS, Schulte PM, Clark TD. Oxygen- and capacity-limited thermal tolerance: blurring ecology and physiology. ACTA ACUST UNITED AC 2018; 221:221/1/jeb169615. [PMID: 29321291 DOI: 10.1242/jeb.169615] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Fredrik Jutfelt
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
| | - Tommy Norin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Rasmus Ern
- Department of Chemistry and Bioscience - Section for Environmental Technology, Aalborg University, 9220 Aalborg, Denmark
| | - Johannes Overgaard
- Department of Bioscience, Zoophysiology, Aarhus University, 8000 Aarhus, Denmark
| | - Tobias Wang
- Department of Bioscience, Zoophysiology, Aarhus University, 8000 Aarhus, Denmark
| | - David J McKenzie
- UMR9190 Centre for Marine Biodiversity Exploitation and Conservation, Université Montpellier, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Sjannie Lefevre
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Göran E Nilsson
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Anthony J R Hickey
- School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Jeroen Brijs
- Department of Biological and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Ben Speers-Roesch
- Department of Biological Sciences, University of New Brunswick, Saint John, NB, Canada, E2L 4L5
| | - Dominique G Roche
- Département d'Éco-Éthologie, Institut de Biologie, Universite de Neuchatel, 2000 Neuchatel, Switzerland
| | - A Kurt Gamperl
- Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada, A1C 5S7
| | - Graham D Raby
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada, N9B 3P4
| | - Rachael Morgan
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Andrew J Esbaugh
- University of Texas at Austin, Marine Science Institute, Port Aransas, TX 78373, USA
| | - Albin Gräns
- Department of Animal Environment and Health, Swedish University of Agricultural Sciences, 532 31 Skara, Sweden
| | - Michael Axelsson
- Department of Biological and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Andreas Ekström
- Department of Biological and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Erik Sandblom
- Department of Biological and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Sandra A Binning
- Département d'Éco-Éthologie, Institut de Biologie, Universite de Neuchatel, 2000 Neuchatel, Switzerland.,Département de Sciences Biologiques, Universite de Montreal, Montreal, QC, Canada, H2V 2S9
| | - James W Hicks
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697-2525, USA
| | - Frank Seebacher
- School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW 2006, Australia
| | | | - Shaun S Killen
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Patricia M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - Timothy D Clark
- Deakin University, School of Life and Environmental Sciences, Geelong, Victoria 3216, Australia
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41
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Bryant HJ, Chung DJ, Schulte PM. Subspecies differences in thermal acclimation of mitochondrial function and the role of uncoupling proteins in killifish. J Exp Biol 2018; 221:jeb.186320. [DOI: 10.1242/jeb.186320] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 10/18/2018] [Indexed: 01/08/2023]
Abstract
Thermal effects on mitochondrial efficiency and ATP production can influence whole-animal thermal tolerance and performance. Thus, organisms may have the capacity to alter mitochondrial processes through acclimation or adaptation to mitigate these effects. One possible mechanism is through the action of uncoupling proteins (UCPs) which can decrease the proton motive force independent of the production of ATP. To test this hypothesis, we examined the mRNA expression patterns of UCP isoforms and characterized the effects of thermal acclimation and putative local thermal adaptation on mitochondrial capacity, proton leak, and P/O ratios in two subspecies of Atlantic killifish (Fundulus heteroclitus). Ucp1 was the dominant isoform in liver and was more highly expressed in northern killifish. We found that cold acclimation increased mitochondrial capacity (state III and maximum substrate oxidation capacity), state II membrane potential, proton leak, and P/O ratios in northern, but not southern killifish liver mitochondria. Palmitate-induced mitochondrial uncoupling was detected in northern, but not southern, killifish liver mitochondria, consistent with the differences in mRNA expression between the subspecies. Taken together, our data suggest that mitochondrial function is more plastic in response to thermal acclimation in northern killifish than southern killifish and that UCP1 may play a role in regulating the proton motive force in northern, but not southern killifish in response to thermal acclimation. These data demonstrate the potential for adaptive variation in mitochondrial plasticity in response to cold.
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Affiliation(s)
- Heather J. Bryant
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4
| | - Dillon J. Chung
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, British Columbia, Canada V6T 1Z4
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42
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Giacomin M, Schulte PM, Wood CM. Differential Effects of Temperature on Oxygen Consumption and Branchial Fluxes of Urea, Ammonia, and Water in the Dogfish Shark (Squalus acanthias suckleyi). Physiol Biochem Zool 2017; 90:627-637. [DOI: 10.1086/694296] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Macqueen DJ, Primmer CR, Houston RD, Nowak BF, Bernatchez L, Bergseth S, Davidson WS, Gallardo-Escárate C, Goldammer T, Guiguen Y, Iturra P, Kijas JW, Koop BF, Lien S, Maass A, Martin SAM, McGinnity P, Montecino M, Naish KA, Nichols KM, Ólafsson K, Omholt SW, Palti Y, Plastow GS, Rexroad CE, Rise ML, Ritchie RJ, Sandve SR, Schulte PM, Tello A, Vidal R, Vik JO, Wargelius A, Yáñez JM. Functional Annotation of All Salmonid Genomes (FAASG): an international initiative supporting future salmonid research, conservation and aquaculture. BMC Genomics 2017; 18:484. [PMID: 28655320 PMCID: PMC5488370 DOI: 10.1186/s12864-017-3862-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 06/14/2017] [Indexed: 11/21/2022] Open
Abstract
We describe an emerging initiative - the 'Functional Annotation of All Salmonid Genomes' (FAASG), which will leverage the extensive trait diversity that has evolved since a whole genome duplication event in the salmonid ancestor, to develop an integrative understanding of the functional genomic basis of phenotypic variation. The outcomes of FAASG will have diverse applications, ranging from improved understanding of genome evolution, to improving the efficiency and sustainability of aquaculture production, supporting the future of fundamental and applied research in an iconic fish lineage of major societal importance.
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Affiliation(s)
- Daniel J. Macqueen
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ UK
| | - Craig R. Primmer
- Department of Biology, University of Turku, 20014 Turku, Finland
| | - Ross D. Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian, EH25 9RG UK
| | - Barbara F. Nowak
- Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, TAS Australia
| | - Louis Bernatchez
- Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, G1V 0A6 Canada
| | - Steinar Bergseth
- The Research Council of Norway, Drammensveien 288, P.O. Box 564, NO-1327 Lysaker, Norway
| | - William S. Davidson
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6 Canada
| | - Cristian Gallardo-Escárate
- Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research, Department of Oceanography, Universidad de Concepción, 4030000 Concepción, Chile
| | - Tom Goldammer
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Fish Genetics Unit, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Yann Guiguen
- INRA, UR1037 Fish Physiology and Genomics, Rennes, France
| | - Patricia Iturra
- Human Genetics Program ICBM Faculty of Medicine, University of Chile, Santiago, Chile
| | | | - Ben F. Koop
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5 Canada
| | - Sigbjørn Lien
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Alejandro Maass
- Center for Mathematical Modelling, Department of Mathematical Engineering, University of Chile, 8370456 Santiago, Chile
- Center for Genome Regulation, University of Chile, 8370456 Santiago, Chile
| | - Samuel A. M. Martin
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ UK
| | - Philip McGinnity
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Martin Montecino
- Center for Biomedical Research, Universidad Andres Bello, 8370146 Santiago, Chile
- FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, 8370146 Santiago, Chile
| | - Kerry A. Naish
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195 USA
| | - Krista M. Nichols
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd E, Seattle, WA 98112 USA
| | | | - Stig W. Omholt
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Yniv Palti
- National Center for Cool and Cold Water Aquaculture, USDA ARS, 11861 Leetown Road, Kearneysville, WV 25430 USA
| | - Graham S. Plastow
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB Canada
| | - Caird E. Rexroad
- Office of National Programs, USDA ARS, 5601 Sunnyside Avenue, Beltsville, MD 20705-5148 USA
| | - Matthew L. Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, 1 Marine Lab Road, St. John’s, NL A1C 5S7 Canada
| | - Rachael J. Ritchie
- Genome British Columbia, Suite 400 – 575, West 8th Avenue, Vancouver, BC V5Z 0C4 Canada
| | - Simen R. Sandve
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4 Canada
| | - Alfredo Tello
- Instituto Tecnológico del Salmón S.A., INTESAL de SalmonChile, Puerto Montt, Chile
| | - Rodrigo Vidal
- Laboratory of Molecular Ecology, Genomics, and Evolutionary Studies, Department of Biology, University of Santiago, 9170022 Santiago, Chile
| | - Jon Olav Vik
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - José Manuel Yáñez
- Faculty of Veterinary and Animal Sciences, University of Chile, Av. Santa Rosa 11735, Santiago, Chile & Aquainnovo, Cardonal s/n, Puerto Montt, Chile
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44
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Gibbons TC, Metzger DCH, Healy TM, Schulte PM. Gene expression plasticity in response to salinity acclimation in threespine stickleback ecotypes from different salinity habitats. Mol Ecol 2017; 26:2711-2725. [DOI: 10.1111/mec.14065] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/01/2017] [Accepted: 02/06/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Taylor C. Gibbons
- Biodiversity Research Centre and Department of Zoology; University of British Columbia; 6270 University Blvd Vancouver BC V6T 1Z4 Canada
| | - David C. H. Metzger
- Biodiversity Research Centre and Department of Zoology; University of British Columbia; 6270 University Blvd Vancouver BC V6T 1Z4 Canada
| | - Timothy M. Healy
- Biodiversity Research Centre and Department of Zoology; University of British Columbia; 6270 University Blvd Vancouver BC V6T 1Z4 Canada
| | - Patricia M. Schulte
- Biodiversity Research Centre and Department of Zoology; University of British Columbia; 6270 University Blvd Vancouver BC V6T 1Z4 Canada
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45
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McKenzie JL, Bucking C, Moreira A, Schulte PM. Intrinsic reproductive isolating mechanisms in the maintenance of a hybrid zone between ecologically divergent subspecies. J Evol Biol 2017; 30:848-864. [PMID: 28190270 DOI: 10.1111/jeb.13055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/24/2017] [Accepted: 02/06/2017] [Indexed: 11/29/2022]
Abstract
Understanding factors involved in maintaining stable hybrid zones is important for predicting the ultimate fate of the interacting taxa, but the relative importance of mechanisms such as ecological selection and intrinsic reproductive isolation remains unclear. Most studies of reproductive isolation in hybrid zones have focused either on zones with strongly bimodal patterns in genotype or phenotype frequencies, with relatively strong isolation, or unimodal zones with relatively weak isolation, whereas less is known about more intermediate classes of hybrid zone. Here, we utilize a hybrid zone of this intermediate type occurring between northern and southern subspecies of Atlantic killifish, Fundulus heteroclitus, to identify isolating mechanisms playing a role in maintaining this type of zone. The two subspecies differ in environmental tolerance, and we found some evidence of microhabitat preference between subspecies within a small tidal creek at the centre of the hybrid zone. There was also an association between sex, mitochondrial genotype and habitat within this creek. Fertilization success did not differ between consubspecific and heterosubspecific crosses, but hatching success was significantly lower for crosses involving southern males and northern females, and crosses between southern females and northern males had altered developmental rates. Southern females and northern males showed patterns consistent with positive assortative mating. Together, these results indicate a role for a combination of factors including assortative mating and/or early hybrid inviability in the maintenance of this hybrid zone and suggest that hybrid zones with intermediate levels of reproductive isolation are likely to be maintained by multiple interacting isolating mechanisms.
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Affiliation(s)
- J L McKenzie
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.,Centre for Aquaculture and Environmental Research, Fisheries and Oceans Canada, West Vancouver, BC, Canada
| | - C Bucking
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - A Moreira
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - P M Schulte
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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Abstract
Human activities are increasing both the frequency of hypoxic episodes and the mean temperature of aquatic ecosystems, but few studies have considered the possibility that acclimation to one of these stressors could improve the ability to cope with the other stressor. Here, we used Atlantic killifish, Fundulus heteroclitus, to test this hypothesis. Hypoxia tolerance was measured as time to loss of equilibrium in hypoxia (LOEhyp) at 0.4 kPa oxygen. Time to LOEhyp declined from 73.3 ± 6.9 min at 15 °C to 2.6 ± 3.8 min at 23 °C, and at 30 °C no fish could withstand this level of hypoxia. Prior acclimation to warm temperatures significantly increased time to LOEhyp. Hypoxia tolerance of the southern subspecies of killifish, F. heteroclitus heteroclitus, was greater than that of the northern subspecies, F. heteroclitus macrolepidotus, measured both as critical oxygen tension (Pcrit) and as time to LOEhyp. Warm acclimation offset the negative effects of temperature on time to LOEhyp to a similar extent in the two subspecies. Warm acclimation increased total lamellar surface area of the gill in both subspecies as a result of regression of an interlamellar cell mass (ILCM). However, differences in total lamellar surface area could not explain differences in time to LOEhyp between the subspecies, suggesting that the lower time to LOEhyp of northern fish is related to their higher routine metabolic rate. These data suggest that thermal plasticity in gill morphology can improve the capacity of this species to tolerate hypoxia, and shows how existing plasticity may help organisms to cope with the complex interacting stressors that they will encounter with increasing frequency as our climate changes.
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Affiliation(s)
- Tara L McBryan
- Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Timothy M Healy
- Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Kristen L Haakons
- Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Patricia M Schulte
- Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
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47
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Healy TM, Bryant HJ, Schulte PM. Mitochondrial genotype and phenotypic plasticity of gene expression in response to cold acclimation in killifish. Mol Ecol 2017; 26:814-830. [DOI: 10.1111/mec.13945] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 11/11/2016] [Accepted: 11/16/2016] [Indexed: 01/07/2023]
Affiliation(s)
- Timothy M. Healy
- Department of Zoology; The University of British Columbia; 6270 University Blvd Vancouver BC Canada V6T 1Z4
| | - Heather J. Bryant
- Department of Zoology; The University of British Columbia; 6270 University Blvd Vancouver BC Canada V6T 1Z4
| | - Patricia M. Schulte
- Department of Zoology; The University of British Columbia; 6270 University Blvd Vancouver BC Canada V6T 1Z4
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48
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Chung DJ, Bryant HJ, Schulte PM. Thermal acclimation and subspecies-specific effects on heart and brain mitochondrial performance in a eurythermal teleost (Fundulus heteroclitus). J Exp Biol 2017; 220:1459-1471. [DOI: 10.1242/jeb.151217] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/30/2017] [Indexed: 01/09/2023]
Abstract
Mitochondrial performance may play a role in setting whole-animal thermal tolerance limits and their plasticity, but the relative roles of adjustments in mitochondrial performance across different highly aerobic tissues remain poorly understood. We compared heart and brain mitochondrial responses to acute thermal challenges and to thermal acclimation using high-resolution respirometry in two locally adapted subspecies of Atlantic killifish (Fundulus heteroclitus). We predicted that 5°C acclimation to would result in compensatory increases in mitochondrial performance, while 33°C acclimation would cause suppression of mitochondrial function to minimize the effects of high temperature on mitochondrial metabolism. In contrast, acclimation to both 33 and 5°C decreased mitochondrial performance compared to fish acclimated to 15°C. These adjustments could represent an energetic cost saving mechanism at temperature extremes. Acclimation responses were similar in both heart and brain; however, this effect was smaller in the heart which might indicate its importance in maintaining whole-animal thermal performance. Alternatively, larger acclimation effects in the brain might indicate greater thermal sensitivity compared to the heart. We detected only modest differences between subspecies that were dependent on the tissue assayed. These data demonstrate extensive plasticity in mitochondrial performance following thermal acclimation in killifish, and indicate that the extent of these responses differs between tissues, highlighting the importance and complexity of mitochondrial regulation in thermal acclimation in eurytherms.
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Affiliation(s)
- Dillon James Chung
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Heather J. Bryant
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, British Columbia, Canada V6T 1Z4
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Metzger DCH, Schulte PM. Maternal stress has divergent effects on gene expression patterns in the brains of male and female threespine stickleback. Proc Biol Sci 2016; 283:rspb.2016.1734. [PMID: 27683372 DOI: 10.1098/rspb.2016.1734] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/05/2016] [Indexed: 11/12/2022] Open
Abstract
Maternal stress can have long-term effects on neurodevelopment that can influence offspring performance and population evolutionary trajectories. To examine the mechanistic basis for these neurodevelopmental effects of maternal stress, we used RNA-seq to assess differential gene expression across the brain transcriptome of adult male and female threespine stickleback (Gasterosteus aculeatus) from stressed and unstressed mothers. We identified sexually divergent effects of maternal stress on the brain transcriptome. In males, genes that were upregulated by maternal stress were enriched for processes involved in synaptic function and organization and steroid hormone-mediated signalling pathways, whereas in females genes that were upregulated by maternal stress were enriched for processes involved in protein translation and metabolic functions. The expression of several genes involved in the hypothalamic-pituitary-interrenal response to stress and epigenetic processes such as the regulation of DNA methylation patterns and miRNAs increased in males and not in females. These data suggest that maternal stress has markedly different effects on cellular pathways in the brains of male and female offspring of mothers that are exposed to stress, which could have important implications when assessing the long-term ecological and evolutionary impacts of stress across generations.
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Affiliation(s)
- David C H Metzger
- Department of Zoology, 6270 University Boulevard, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
| | - Patricia M Schulte
- Department of Zoology, 6270 University Boulevard, University of British Columbia, Vancouver, BC, Canada V6T 1Z4
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50
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McKenzie JL, Dhillon RS, Schulte PM. Steep, coincident, and concordant clines in mitochondrial and nuclear-encoded genes in a hybrid zone between subspecies of Atlantic killifish, Fundulus heteroclitus. Ecol Evol 2016; 6:5771-87. [PMID: 27547353 PMCID: PMC4983590 DOI: 10.1002/ece3.2324] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/23/2016] [Accepted: 06/27/2016] [Indexed: 01/15/2023] Open
Abstract
Steep genetic clines resulting from recent secondary contact between previously isolated taxa can either gradually erode over time or be stabilized by factors such as ecological selection or selection against hybrids. We used patterns of variation in 30 nuclear and two mitochondrial SNPs to examine the factors that could be involved in stabilizing clines across a hybrid zone between two subspecies of the Atlantic killifish, Fundulus heteroclitus. Increased heterozygote deficit and cytonuclear disequilibrium in populations near the center of the mtDNA cline suggest that some form of reproductive isolation such as assortative mating or selection against hybrids may be acting in this hybrid zone. However, only a small number of loci exhibited these signatures, suggesting locus-specific, rather than genomewide, factors. Fourteen of the 32 loci surveyed had cline widths inconsistent with neutral expectations, with two SNPs in the mitochondrial genome exhibiting the steepest clines. Seven of the 12 putatively non-neutral nuclear clines were for SNPs in genes related to oxidative metabolism. Among these putatively non-neutral nuclear clines, SNPs in two nuclear-encoded mitochondrial genes (SLC25A3 and HDDC2), as well as SNPs in the myoglobin, 40S ribosomal protein S17, and actin-binding LIM protein genes, had clines that were coincident and concordant with the mitochondrial clines. When hybrid index was calculated using this subset of loci, the frequency distribution of hybrid indices for a population located at the mtDNA cline center was non-unimodal, suggesting selection against advanced-generation hybrids, possibly due to effects on processes involved in oxidative metabolism.
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Affiliation(s)
- Jessica L McKenzie
- Department of Zoology University of British Columbia Vancouver British Columbia Canada; Centre for Aquaculture and Environmental Research Fisheries and Oceans Canada West Vancouver British Columbia Canada
| | - Rashpal S Dhillon
- Department of Zoology University of British Columbia Vancouver British Columbia Canada; Present address: Department of Biomolecular Chemistry Epigenetics Theme Wisconsin Institute for Discovery University of Wisconsin Madison Wisconsin
| | - Patricia M Schulte
- Department of Zoology University of British Columbia Vancouver British Columbia Canada
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