1
|
Gómez‐Blanco D, Tobler M, Hasselquist D. Why and when should organisms elongate their telomeres? Elaborations on the 'excess resources elongation' and 'last resort elongation' hypotheses. Ecol Evol 2023; 13:e10825. [PMID: 38099139 PMCID: PMC10719541 DOI: 10.1002/ece3.10825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 10/31/2023] [Accepted: 11/28/2023] [Indexed: 12/17/2023] Open
Abstract
Telomere length and telomere shortening are thought to be critical cellular attributes and processes that are related to an individual's life span and fitness. The general pattern across most taxa is that after birth telomere length gradually decreases with age. Telomere protection and restoration mechanisms are usually assumed to reduce the rate of shortening or at most keep telomere length constant. However, here we have compiled a list of 26 articles showing that there is an increasing number of studies reporting apparent elongation of telomeres (i.e., a net increase in TL from timet to timet+1) often in a considerable proportion of the individuals studied. Moreover, the few studies which have studied telomere elongation in detail show that increases in telomere length are unlikely to be due to measurement error alone. In this article, we argue that episodes of telomere elongation deserve more attention as they could reflect individual strategies to optimise life histories and maximise fitness, which may not be reflected in the overall telomere dynamics patterns. We propose that patterns of telomere (net) elongation may be partly determined by other factors than those causing telomere shortening, and therefore deserve analyses specifically targeted to investigate the occurrence of telomere elongation. We elaborate on two ecological hypotheses that have been proposed to explain patterns of telomere elongation (the 'excess resources elongation' and the 'last resort elongation' hypothesis) and we discuss the current evidence for (or against) these hypotheses and propose ways to test them.
Collapse
|
2
|
Ryan K, Greenway R, Landers J, Arias-Rodriguez L, Tobler M, Kelley JL. Selection on standing genetic variation mediates convergent evolution in extremophile fish. Mol Ecol 2023; 32:5042-5054. [PMID: 37548336 DOI: 10.1111/mec.17081] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/23/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023]
Abstract
Hydrogen sulfide is a toxic gas that disrupts numerous biological processes, including energy production in the mitochondria, yet fish in the Poecilia mexicana species complex have independently evolved sulfide tolerance several times. Despite clear evidence for convergence at the phenotypic level in these fishes, it is unclear if the repeated evolution of hydrogen sulfide tolerance is the result of similar genomic changes. To address this gap, we used a targeted capture approach to sequence genes associated with sulfide processes and toxicity from five sulfidic and five nonsulfidic populations in the species complex. By comparing sequence variation in candidate genes to a reference set, we identified similar population structure and differentiation, suggesting that patterns of variation in most genes associated with sulfide processes and toxicity are due to demographic history and not selection. But the presence of tree discordance for a subset of genes suggests that several loci are evolving divergently between ecotypes. We identified two differentiation outlier genes that are associated with sulfide detoxification in the mitochondria that have signatures of selection in all five sulfidic populations. Further investigation into these regions identified long, shared haplotypes among sulfidic populations. Together, these results reveal that selection on standing genetic variation in putatively adaptive genes may be driving phenotypic convergence in this species complex.
Collapse
Affiliation(s)
- Kara Ryan
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Ryan Greenway
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Constance, Germany
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Jake Landers
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), Villahermosa, Mexico
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| |
Collapse
|
3
|
Xiong Y, Tobler M, Hegemann A, Hasselquist DL. Assessment of avian health status: suitability and constraints of the Zoetis VetScan VS2 blood analyser for ecological and evolutionary studies. Biol Open 2023; 12:bio060009. [PMID: 37485865 PMCID: PMC10399204 DOI: 10.1242/bio.060009] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Biochemical analyses of blood can decipher physiological conditions of living animals and unravel mechanistic underpinnings of life-history strategies and trade-offs. Yet, researchers in ecology and evolution often face constraints in which methods to apply, not least due to blood volume restrictions or field settings. Here, we test the suitability of a portable biochemical analyser (Zoetis VetScan VS2) for ecological and evolutionary studies that may help solve those problems. Using as little as 80 µl of whole-bird blood from free-living Jackdaws (Corvus monedula) and captive Zebra Finches (Taeniopygia guttata), we show that eight (out of 10) blood analytes show high repeatability after short-term storage (approximately 2 h) and six after 12 h storage time. Handling stress had a clear impact on all except two analytes by 16 min after catching. Finally, six analytes showed consistency within individuals over a period of 30 days, and three even showed individual consistency over a year. Taken together, we conclude that the VetScan VS2 captures biologically relevant variation in blood analytes using just 80 µl of whole blood and, thus, provides valuable physiological measurements of (small) birds sampled in semi-field and field conditions.
Collapse
Affiliation(s)
- Ye Xiong
- Department of Biology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Michael Tobler
- Department of Biology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Arne Hegemann
- Department of Biology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Dennis L Hasselquist
- Department of Biology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| |
Collapse
|
4
|
Tobler M, Gómez-Blanco D, Hegemann A, Lapa M, Neto JM, Tarka M, Xiong Y, Hasselquist D. Telomeres in ecology and evolution: A review and classification of hypotheses. Mol Ecol 2022; 31:5946-5965. [PMID: 34865259 DOI: 10.1111/mec.16308] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [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: 04/28/2021] [Revised: 11/19/2021] [Accepted: 12/01/2021] [Indexed: 01/31/2023]
Abstract
Research on telomeres in the fields of ecology and evolution has been rapidly expanding over the last two decades. This has resulted in the formulation of a multitude of, often name-given, hypotheses related to the associations between telomeres and life-history traits or fitness-facilitating processes (and the mechanisms underlying them). However, the differences (or similarities) between the various hypotheses, which can originate from different research fields, are often not obvious. Our aim here is therefore to give an overview of the hypotheses that are of interest in ecology and evolution and to provide two frameworks that help discriminate among them. We group the hypotheses (i) based on their association with different research questions, and (ii) using a hierarchical approach that builds on the assumptions they make, such as about causality of telomere length/shortening and/or the proposed functional consequences of telomere shortening on organism performance. Both our frameworks show that there exist parallel lines of thoughts in different research fields. Moreover, they also clearly illustrate that there are in many cases competing hypotheses within clusters, and that some of these even have contradictory assumptions and/or predictions. We also touch upon two topics in telomere research that would benefit from further conceptualization. This review should help researchers, both those familiar with and those new to the subject, to identify future avenues of research.
Collapse
Affiliation(s)
| | | | - Arne Hegemann
- Department of Biology, Lund University, Lund, Sweden
| | - Mariana Lapa
- Department of Biology, Lund University, Lund, Sweden
| | - Júlio M Neto
- Department of Biology, Lund University, Lund, Sweden
| | - Maja Tarka
- Department of Biology, Lund University, Lund, Sweden
| | - Ye Xiong
- Department of Biology, Lund University, Lund, Sweden
| | | |
Collapse
|
5
|
Coffin JL, Kelley JL, Jeyasingh PD, Tobler M. Impacts of heavy metal pollution on the ionomes and transcriptomes of Western mosquitofish (Gambusia affinis). Mol Ecol 2022; 31:1527-1542. [PMID: 35000238 DOI: 10.1111/mec.16342] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 05/04/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/26/2022]
Abstract
Our understanding of the mechanisms mediating the resilience of organisms to environmental change remains lacking. Heavy metals negatively affect processes at all biological scales, yet organisms inhabiting contaminated environments must maintain homeostasis to survive. Tar Creek in Oklahoma, USA, contains high concentrations of heavy metals and an abundance of Western mosquitofish (Gambusia affinis), though several fish species persist at lower frequency. To test hypotheses about the mechanisms mediating the persistence and abundance of mosquitofish in Tar Creek, we integrated ionomic data from seven resident fish species and transcriptomic data from mosquitofish to test hypotheses about the mechanisms mediating the persistence of mosquitofish in Tar Creek. We predicted that mosquitofish minimize uptake of heavy metals more than other Tar Creek fish inhabitants and induce transcriptional responses to detoxify metals that enter the body, allowing them to persist in Tar Creek at higher density than species that may lack these responses. Tar Creek populations of all seven fish species accumulated heavy metals, suggesting mosquitofish cannot block uptake more efficiently than other species. We found population-level gene expression changes between mosquitofish in Tar Creek and nearby unpolluted sites. Gene expression differences primarily occurred in the gill, where we found upregulation of genes involved with lowering transfer of metal ions from the blood into cells and mitigating free radicals. However, many differentially expressed genes were not in known metal response pathways, suggesting multifarious selective regimes and/or previously undocumented pathways could impact tolerance in mosquitofish. Our systems-level study identified well characterized and putatively new mechanisms that enable mosquitofish to inhabit heavy metal-contaminated environments.
Collapse
Affiliation(s)
- John L Coffin
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Punidan D Jeyasingh
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| |
Collapse
|
6
|
Owens GL, Veen T, Moxley DR, Arias-Rodriguez L, Tobler M, Rennison DJ. Parallel shifts of visual sensitivity and body coloration in replicate populations of extremophile fish. Mol Ecol 2021; 31:946-958. [PMID: 34784095 DOI: 10.1111/mec.16279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 06/17/2021] [Revised: 11/02/2021] [Accepted: 11/11/2021] [Indexed: 12/20/2022]
Abstract
Visual sensitivity and body pigmentation are often shaped by both natural selection from the environment and sexual selection from mate choice. One way of quantifying the impact of the environment is by measuring how traits have changed after colonization of a novel habitat. To do this, we studied Poecilia mexicana populations that have repeatedly adapted to extreme sulphidic (H2 S-containing) environments. We measured visual sensitivity using opsin gene expression, as well as body pigmentation, for populations in four independent drainages. Both visual sensitivity and body pigmentation showed significant parallel shifts towards greater medium-wavelength sensitivity and reflectance in sulphidic populations. Altogether we found that sulphidic habitats select for differences in visual sensitivity and pigmentation. Shifts between habitats may be due to both differences in the water's spectral properties and correlated ecological changes.
Collapse
Affiliation(s)
- Gregory L Owens
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Thor Veen
- Quest University, Squamish, British Columbia, Canada
| | - Dylan R Moxley
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Mexico
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Diana J Rennison
- Division of Biological Sciences, University of California San Diego, San Diego, California, USA
| |
Collapse
|
7
|
Hasselquist D, Tobler M. The Accumulating Costs Hypothesis—to Better Understand Delayed “Hidden” Costs of Seemingly Mild Disease and Other Moderate Stressors. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.685057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mild diseases and moderate stressors are seemingly harmless and are therefore often assumed to have negligible impact on Darwinian fitness. Here we argue that the effects of “benign” parasites and other moderate stressors may have a greater impact on lifespan and other fitness traits than generally thought. We outline the “accumulating costs” hypothesis which proposes that moderate strains on the body caused by mild diseases and other moderate stressors that occur throughout life will result in small irreversible “somatic lesions” that initially are invisible (i.e., induce “hidden” costs). However, over time these somatic lesions accumulate until their summed effect reaches a critical point when cell senescence and malfunction begin to affect organ functionality and lead to the onset of degenerative diseases and aging. We briefly discuss three potential mechanisms through which the effects of moderate strains (e.g., mild diseases) could accumulate: Accelerated telomere shortening, loss of repetitious cell compartments and other uncorrected DNA damage in the genome. We suggest that telomere shortening may be a key candidate for further research with respect to the accumulating costs hypothesis. Telomeres can acquire lesions from moderate strains without immediate negative effects, lesions can be accumulated over time and lead to a critically short telomere length, which may eventually cause severe somatic malfunctioning, including aging. If effects of mild diseases, benign parasites and moderate stressors accrued throughout life can have severe delayed consequences, this might contribute to our understanding of life history strategies and trade-offs, and have important implications for medicine, including consideration of treatment therapies for mild (chronic) infections such as malaria.
Collapse
|
8
|
Kelley JL, Desvignes T, McGowan KL, Perez M, Rodriguez LA, Brown AP, Culumber Z, Tobler M. microRNA expression variation as a potential molecular mechanism contributing to adaptation to hydrogen sulphide. J Evol Biol 2020; 34:977-988. [PMID: 33124163 DOI: 10.1111/jeb.13727] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/18/2020] [Accepted: 10/19/2020] [Indexed: 12/28/2022]
Abstract
microRNAs (miRNAs) are post-transcriptional regulators of gene expression and can play an important role in modulating organismal development and physiology in response to environmental stress. However, the role of miRNAs in mediating adaptation to diverse environments in natural study systems remains largely unexplored. Here, we characterized miRNAs and their expression in Poecilia mexicana, a species of small fish that inhabits both normal streams and extreme environments in the form of springs rich in toxic hydrogen sulphide (H2 S). We found that P. mexicana has a similar number of miRNA genes as other teleosts. In addition, we identified a large population of mature miRNAs that were differentially expressed between locally adapted populations in contrasting habitats, indicating that miRNAs may contribute to P. mexicana adaptation to sulphidic environments. In silico identification of differentially expressed miRNA-mRNA pairs revealed, in the sulphidic environment, the downregulation of miRNAs predicted to target mRNAs involved in sulphide detoxification and cellular homeostasis, which are pathways essential for life in H2 S-rich springs. In addition, we found that predicted targets of upregulated miRNAs act in the mitochondria (16.6% of predicted annotated targets), which is the main site of H2 S toxicity and detoxification, possibly modulating mitochondrial function. Together, the differential regulation of miRNAs between these natural populations suggests that miRNAs may be involved in H2 S adaptation by promoting functions needed for survival and reducing functions affected by H2 S. This study lays the groundwork for further research to directly demonstrate the role of miRNAs in adaptation to H2 S. Overall, this study provides a critical stepping-stone towards a comprehensive understanding of the regulatory mechanisms underlying the adaptive variation in gene expression in a natural system.
Collapse
Affiliation(s)
- Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Thomas Desvignes
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Kerry L McGowan
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Marcos Perez
- School of Molecular Biosciences, Washington State University, Pullman, WA, USA
| | - Lenin Arias Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), Villahermosa, México
| | - Anthony P Brown
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Zach Culumber
- Biological Sciences Department, University of Alabama in Huntsville, Huntsville, AL, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| |
Collapse
|
9
|
Greenway R, Barts N, Henpita C, Brown AP, Arias Rodriguez L, Rodríguez Peña CM, Arndt S, Lau GY, Murphy MP, Wu L, Lin D, Tobler M, Kelley JL, Shaw JH. Convergent evolution of conserved mitochondrial pathways underlies repeated adaptation to extreme environments. Proc Natl Acad Sci U S A 2020; 117:16424-16430. [PMID: 32586956 PMCID: PMC7368198 DOI: 10.1073/pnas.2004223117] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [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: 03/09/2020] [Accepted: 05/21/2020] [Indexed: 02/07/2023] Open
Abstract
Extreme environments test the limits of life; yet, some organisms thrive in harsh conditions. Extremophile lineages inspire questions about how organisms can tolerate physiochemical stressors and whether the repeated colonization of extreme environments is facilitated by predictable and repeatable evolutionary innovations. We identified the mechanistic basis underlying convergent evolution of tolerance to hydrogen sulfide (H2S)-a toxicant that impairs mitochondrial function-across evolutionarily independent lineages of a fish (Poecilia mexicana, Poeciliidae) from H2S-rich springs. Using comparative biochemical and physiological analyses, we found that mitochondrial function is maintained in the presence of H2S in sulfide spring P. mexicana but not ancestral lineages from nonsulfidic habitats due to convergent adaptations in the primary toxicity target and a major detoxification enzyme. Genome-wide local ancestry analyses indicated that convergent evolution of increased H2S tolerance in different populations is likely caused by a combination of selection on standing genetic variation and de novo mutations. On a macroevolutionary scale, H2S tolerance in 10 independent lineages of sulfide spring fishes across multiple genera of Poeciliidae is correlated with the convergent modification and expression changes in genes associated with H2S toxicity and detoxification. Our results demonstrate that the modification of highly conserved physiological pathways associated with essential mitochondrial processes mediates tolerance to physiochemical stress. In addition, the same pathways, genes, and-in some instances-codons are implicated in H2S adaptation in lineages that span 40 million years of evolution.
Collapse
Affiliation(s)
- Ryan Greenway
- Division of Biology, Kansas State University, Manhattan, KS 66506
| | - Nick Barts
- Division of Biology, Kansas State University, Manhattan, KS 66506
| | - Chathurika Henpita
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK 74078
| | - Anthony P Brown
- School of Biological Sciences, Washington State University, Pullman, WA 99163
| | - Lenin Arias Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, 86150, Mexico
| | - Carlos M Rodríguez Peña
- Instituto de Investigaciones Botánicas y Zoológicas, Universidad Autónoma de Santo Domingo, Santo Domingo, 10105, Dominican Republic
| | - Sabine Arndt
- Medical Research Council - Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, United Kingdom
| | - Gigi Y Lau
- Department of Biosciences, University of Oslo, 0315 Oslo, Norway
| | - Michael P Murphy
- Medical Research Council - Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, United Kingdom
| | - Lei Wu
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK 74078
| | - Dingbo Lin
- Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK 74078
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS 66506;
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA 99163;
| | - Jennifer H Shaw
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK 74078;
| |
Collapse
|
10
|
Tobler M, Barts N, Greenway R. Mitochondria and the Origin of Species: Bridging Genetic and Ecological Perspectives on Speciation Processes. Integr Comp Biol 2020; 59:900-911. [PMID: 31004483 DOI: 10.1093/icb/icz025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Mitochondria have been known to be involved in speciation through the generation of Dobzhansky-Muller incompatibilities, where functionally neutral co-evolution between mitochondrial and nuclear genomes can cause dysfunction when alleles are recombined in hybrids. We propose that adaptive mitochondrial divergence between populations can not only produce intrinsic (Dobzhansky-Muller) incompatibilities, but could also contribute to reproductive isolation through natural and sexual selection against migrants, post-mating prezygotic isolation, as well as by causing extrinsic reductions in hybrid fitness. We describe how these reproductive isolating barriers can potentially arise through adaptive divergence of mitochondrial function in the absence of mito-nuclear coevolution, a departure from more established views. While a role for mitochondria in the speciation process appears promising, we also highlight critical gaps of knowledge: (1) many systems with a potential for mitochondrially-mediated reproductive isolation lack crucial evidence directly linking reproductive isolation and mitochondrial function; (2) it often remains to be seen if mitochondrial barriers are a driver or a consequence of reproductive isolation; (3) the presence of substantial gene flow in the presence of mito-nuclear incompatibilities raises questions whether such incompatibilities are strong enough to drive speciation to completion; and (4) it remains to be tested how mitochondrial effects on reproductive isolation compare when multiple mechanisms of reproductive isolation coincide. We hope this perspective and the proposed research plans help to inform future studies of mitochondrial adaptation in a manner that links genotypic changes to phenotypic adaptations, fitness, and reproductive isolation in natural systems, helping to clarify the importance of mitochondria in the formation and maintenance of biological diversity.
Collapse
Affiliation(s)
- M Tobler
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - N Barts
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - R Greenway
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| |
Collapse
|
11
|
Camarillo H, Arias Rodriguez L, Tobler M. Functional consequences of phenotypic variation between locally adapted populations: Swimming performance and ventilation in extremophile fish. J Evol Biol 2020; 33:512-523. [DOI: 10.1111/jeb.13586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 01/06/2020] [Accepted: 01/09/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Henry Camarillo
- Division of Biology Kansas State University Manhattan KS USA
| | - Lenin Arias Rodriguez
- División Académica de Ciencias Biológicas Universidad Juárez Autónoma de Tabasco Villahermosa México
| | - Michael Tobler
- Division of Biology Kansas State University Manhattan KS USA
| |
Collapse
|
12
|
McGowan KL, Passow CN, Arias-Rodriguez L, Tobler M, Kelley JL. Expression analyses of cave mollies ( Poecilia mexicana) reveal key genes involved in the early evolution of eye regression. Biol Lett 2019; 15:20190554. [PMID: 31640527 DOI: 10.1098/rsbl.2019.0554] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Eye regression occurs across cave-dwelling populations of many species and is often coupled with a decrease or loss in eye function. Teleost fishes are among the few vertebrates to undergo widespread colonization of caves and often exhibit eye regression with blindness. Cave populations of the poeciliid fish Poecilia mexicana (cave molly) exhibit reduced-albeit functional-eyes, offering the opportunity to investigate partial eye regression. We sequenced eye transcriptomes of cave and surface populations of P. mexicana to identify differentially expressed genes that potentially underlie eye regression in cave mollies. We identified 28 significantly differentially expressed genes, 20 of which were directly related to light sensitivity, eye structure and visual signaling. Twenty-six of these genes were downregulated in cave compared to surface populations. Functional enrichment analysis revealed eye-related gene ontologies that were under-represented in cave mollies. In addition, a set of co-expressed genes related to vision and circadian rhythm was correlated with habitat type (cave versus surface). Our study suggests that differential gene expression plays a key role in the beginning evolutionary stages of eye regression in P. mexicana, shedding further light on regressive evolution in cavefish.
Collapse
Affiliation(s)
- Kerry L McGowan
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| | - Courtney N Passow
- Department of Ecology, Evolution and Behavior, University of Minnesota-Twin Cities, St. Paul, MN 55108, USA.,Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco 86150, Mexico
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA
| |
Collapse
|
13
|
Brown AP, McGowan KL, Schwarzkopf EJ, Greenway R, Rodriguez LA, Tobler M, Kelley JL. Local ancestry analysis reveals genomic convergence in extremophile fishes. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180240. [PMID: 31154969 DOI: 10.1098/rstb.2018.0240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The molecular basis of convergent phenotypes is often unknown. However, convergence at a genomic level is predicted when there are large population sizes, gene flow among diverging lineages or strong genetic constraints. We used whole-genome resequencing to investigate genomic convergence in fishes ( Poecilia spp.) that have repeatedly colonized hydrogen sulfide (H2S)-rich environments in Mexico. We identified genomic similarities in both single nucleotide polymorphisms (SNPs) and structural variants (SVs) among independently derived sulfide spring populations, with approximately 1.2% of the genome being shared among sulfidic ecotypes. We compared these convergent genomic regions to candidate genes for H2S adaptation identified from transcriptomic analyses and found that a significant proportion of these candidate genes (8%) were also in regions where sulfidic individuals had similar SNPs, while only 1.7% were in regions where sulfidic individuals had similar SVs. Those candidate genes included genes involved in sulfide detoxification, the electron transport chain (the main toxicity target of H2S) and other processes putatively important for adaptation to sulfidic environments. Regional genomic similarity across independent populations exposed to the same source of selection is consistent with selection on standing variation or introgression of adaptive alleles across divergent lineages. However, combined with previous analyses, our data also support that adaptive changes in mitochondrially encoded subunits arose independently via selection on de novo mutations. Pressing questions remain on what conditions ultimately facilitate the independent rise of adaptive alleles at the same loci in separate populations, and thus, the degree to which evolution is repeatable or predictable. This article is part of the theme issue 'Convergent evolution in the genomics era: new insights and directions'.
Collapse
Affiliation(s)
- Anthony P Brown
- 1 School of Biological Sciences, Washington State University , 100 Dairy Road, Pullman, WA 99164 , USA
| | - Kerry L McGowan
- 1 School of Biological Sciences, Washington State University , 100 Dairy Road, Pullman, WA 99164 , USA
| | - Enrique J Schwarzkopf
- 1 School of Biological Sciences, Washington State University , 100 Dairy Road, Pullman, WA 99164 , USA
| | - Ryan Greenway
- 2 Division of Biology, Kansas State University , 116 Ackert Hall, Manhattan, KS 66506 , USA
| | - Lenin Arias Rodriguez
- 3 División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT) , CP 86150 Villahermosa, Tabasco , México
| | - Michael Tobler
- 2 Division of Biology, Kansas State University , 116 Ackert Hall, Manhattan, KS 66506 , USA
| | - Joanna L Kelley
- 1 School of Biological Sciences, Washington State University , 100 Dairy Road, Pullman, WA 99164 , USA
| |
Collapse
|
14
|
Lau GY, Barts N, Hartley RC, Tobler M, Richards JG, Murphy MP, Arndt S. Detection of changes in mitochondrial hydrogen sulfide i n vivo in the fish model Poecilia mexicana (Poeciliidae). Biol Open 2019; 8:8/5/bio041467. [PMID: 31072908 PMCID: PMC6550084 DOI: 10.1242/bio.041467] [Citation(s) in RCA: 5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In this paper, we outline the use of a mitochondria-targeted ratiometric mass spectrometry probe, MitoA, to detect in vivo changes in mitochondrial hydrogen sulfide (H2S) in Poecilia mexicana (family Poeciliidae). MitoA is introduced via intraperitoneal injection into the animal and is taken up by mitochondria, where it reacts with H2S to form the product MitoN. The MitoN/MitoA ratio can be used to assess relative changes in the amounts of mitochondrial H2S produced over time. We describe the use of MitoA in the fish species P. mexicana to illustrate the steps for adopting the use of MitoA in a new organism, including extraction and purification of MitoA and MitoN from tissues followed by tandem mass spectrometry. In this proof-of-concept study we exposed H2S tolerant P. mexicana to 59 µM free H2S for 5 h, which resulted in increased MitoN/MitoA in brain and gills, but not in liver or muscle, demonstrating increased mitochondrial H2S levels in select tissues following whole-animal H2S exposure. This is the first time that accumulation of H2S has been observed in vivo during whole-animal exposure to free H2S using MitoA. This article has an associated First Person interview with the first author of the paper.
Collapse
Affiliation(s)
- Gigi Y. Lau
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada,Authors for correspondence (, )
| | - Nicholas Barts
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| | - Richard C. Hartley
- WestCHEM School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| | - Jeffrey G. Richards
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - Michael P. Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - Sabine Arndt
- MRC Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK .,Institute for Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstr. 1, Mainz 55131, Germany
| |
Collapse
|
15
|
Greenway R, McNemee R, Okamoto A, Plath M, Arias‐Rodriguez L, Tobler M. Correlated divergence of female and male genitalia in replicated lineages with ongoing ecological speciation. Evolution 2019; 73:1200-1212. [DOI: 10.1111/evo.13742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 03/28/2019] [Accepted: 04/03/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Ryan Greenway
- Division of Biology Kansas State University Manhattan Kansas 66506
| | - Rachel McNemee
- Division of Biology Kansas State University Manhattan Kansas 66506
| | - Alexander Okamoto
- Division of Biology Kansas State University Manhattan Kansas 66506
- Department of Organismal Biology and Anatomy The University of Chicago Chicago Illinois 60637
| | - Martin Plath
- College of Animal Science and Technology Northwest A&F University Yangling Shaanxi PR China
| | - Lenin Arias‐Rodriguez
- División Académica de Ciencias Biológicas Universidad Juárez Autónoma de Tabasco Villahermosa Tabasco México
| | - Michael Tobler
- Division of Biology Kansas State University Manhattan Kansas 66506
| |
Collapse
|
16
|
Hotaling S, Quackenbush CR, Bennett-Ponsford J, New DD, Arias-Rodriguez L, Tobler M, Kelley JL. Bacterial Diversity in Replicated Hydrogen Sulfide-Rich Streams. Microb Ecol 2019; 77:559-573. [PMID: 30105506 DOI: 10.1007/s00248-018-1237-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 01/13/2018] [Accepted: 07/23/2018] [Indexed: 06/08/2023]
Abstract
Extreme environments typically require costly adaptations for survival, an attribute that often translates to an elevated influence of habitat conditions on biotic communities. Microbes, primarily bacteria, are successful colonizers of extreme environments worldwide, yet in many instances, the interplay between harsh conditions, dispersal, and microbial biogeography remains unclear. This lack of clarity is particularly true for habitats where extreme temperature is not the overarching stressor, highlighting a need for studies that focus on the role other primary stressors (e.g., toxicants) play in shaping biogeographic patterns. In this study, we leveraged a naturally paired stream system in southern Mexico to explore how elevated hydrogen sulfide (H2S) influences microbial diversity. We sequenced a portion of the 16S rRNA gene using bacterial primers for water sampled from three geographically proximate pairings of streams with high (> 20 μM) or low (~ 0 μM) H2S concentrations. After exploring bacterial diversity within and among sites, we compared our results to a previous study of macroinvertebrates and fish for the same sites. By spanning multiple organismal groups, we were able to illuminate how H2S may differentially affect biodiversity. The presence of elevated H2S had no effect on overall bacterial diversity (p = 0.21), a large effect on community composition (25.8% of variation explained, p < 0.0001), and variable influence depending upon the group-whether fish, macroinvertebrates, or bacteria-being considered. For bacterial diversity, we recovered nine abundant operational taxonomic units (OTUs) that comprised a core H2S-rich stream microbiome in the region. Many H2S-associated OTUs were members of the Epsilonproteobacteria and Gammaproteobacteria, which both have been implicated in endosymbiotic relationships between sulfur-oxidizing bacteria and eukaryotes, suggesting the potential for symbioses that remain to be discovered in these habitats.
Collapse
Affiliation(s)
- Scott Hotaling
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Corey R Quackenbush
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | | | - Daniel D New
- Institute for Bioinformatics and Evolutionary Studies (IBEST), University of Idaho, Moscow, ID, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA.
| |
Collapse
|
17
|
Frenette BD, Bruckerhoff LA, Tobler M, Gido KB. Temperature effects on performance and physiology of two prairie stream minnows. Conserv Physiol 2019; 7:coz063. [PMID: 31687142 PMCID: PMC6822539 DOI: 10.1093/conphys/coz063] [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] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 04/10/2019] [Accepted: 07/28/2019] [Indexed: 05/10/2023]
Abstract
Earth's atmosphere has warmed by ~1°C over the past century and continues to warm at an increasing rate. Effects of atmospheric warming are already visible in most major ecosystems and are evident across all levels of biological organization. Linking functional responses of individuals to temperature is critical for predicting responses of populations and communities to global climate change. The southern redbelly dace Chrosomus erythrogaster and the central stoneroller Campostoma anomalum are two minnows (Cyprinidae) that commonly occur in the Flint Hills region of the USA but show different patterns of occurrence, with dace largely occupying headwater reaches and stonerollers persisting in both headwater and intermediate-sized streams. We tested for differences between species in critical thermal maximum, energy metabolism, sustained swimming and activity over an ecologically relevant temperature gradient of acclimation temperatures. Typically, metrics increased with acclimation temperature for both species, although stoneroller activity decreased with temperature. We observed a significant interaction between species and temperature for critical thermal maxima, where stonerollers only had higher critical thermal maxima at the coldest temperature and at warm temperatures compared to the dace. We did not find evidence suggesting differences in the energy metabolism of dace and stonerollers. We detected interspecific differences in sustained swimming performance, with dace having higher swimming speed than stonerollers regardless of acclimation temperature. Finally, there was a significant interaction between temperature and species for activity; dace activity was higher at intermediate and warm temperatures compared to stonerollers. We observed subtle interspecific differences in how performance metrics responded to temperature that did not always align with observed patterns of distribution for these species. Thus, other ecological factors likely are important drivers of distributional patterns in these species.
Collapse
Affiliation(s)
- Bryan D Frenette
- Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA
- Corresponding author: Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA.
| | - Lindsey A Bruckerhoff
- Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA
| | - Keith B Gido
- Division of Biology, Kansas State University, 166 Ackert Hall, Manhattan, KS 66506, USA
| |
Collapse
|
18
|
Brown AP, Arias-Rodriguez L, Yee MC, Tobler M, Kelley JL. Concordant Changes in Gene Expression and Nucleotides Underlie Independent Adaptation to Hydrogen-Sulfide-Rich Environments. Genome Biol Evol 2018; 10:2867-2881. [PMID: 30215710 PMCID: PMC6225894 DOI: 10.1093/gbe/evy198] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2018] [Indexed: 12/23/2022] Open
Abstract
The colonization of novel environments often involves changes in gene expression, protein coding sequence, or both. Studies of how populations adapt to novel conditions, however, often focus on only one of these two processes, potentially missing out on the relative importance of different parts of the evolutionary process. In this study, our objectives were 1) to better understand the qualitative concordance between conclusions drawn from analyses of differential expression and changes in genic sequence and 2) to quantitatively test whether differentially expressed genes were enriched for sites putatively under positive selection within gene regions. To achieve this, we compared populations of fish (Poecilia mexicana) that have independently adapted to hydrogen-sulfide-rich environments in southern Mexico to adjacent populations residing in nonsulfidic waters. Specifically, we used RNA-sequencing data to compare both gene expression and DNA sequence differences between populations. Analyzing these two different data types led to similar conclusions about which biochemical pathways (sulfide detoxification and cellular respiration) were involved in adaptation to sulfidic environments. Additionally, we found a greater overlap between genes putatively under selection and differentially expressed genes than expected by chance. We conclude that considering both differential expression and changes in DNA sequence led to a more comprehensive understanding of how these populations adapted to extreme environmental conditions. Our results imply that changes in both gene expression and DNA sequence-sometimes at the same loci-may be involved in adaptation.
Collapse
Affiliation(s)
- Anthony P Brown
- School of Biological Sciences, Washington State University, 100 Dairy Road, Pullman, WA 99164
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), C.P. 86150, Villahermosa, Tabasco, México
| | - Muh-Ching Yee
- Stanford Functional Genomics Facility, CCSR 0120, Stanford, CA 94305
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, 100 Dairy Road, Pullman, WA 99164
| |
Collapse
|
19
|
von Wolff M, Nakas CT, Tobler M, Merz TM, Hilty MP, Veldhuis JD, Huber AR, Pichler Hefti J. Adrenal, thyroid and gonadal axes are affected at high altitude. Endocr Connect 2018; 7:1081-1089. [PMID: 30352395 PMCID: PMC6198189 DOI: 10.1530/ec-18-0242] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 08/29/2018] [Indexed: 11/08/2022]
Abstract
Humans cannot live at very high altitude for reasons, which are not completely understood. Since these reasons are not restricted to cardiorespiratory changes alone, changes in the endocrine system might also be involved. Therefore, hormonal changes during prolonged hypobaric hypoxia were comprehensively assessed to determine effects of altitude and hypoxia on stress, thyroid and gonadal hypothalamus-pituitary hormone axes. Twenty-one male and 19 female participants were examined repetitively during a high-altitude expedition. Cortisol, prolactin, thyroid-stimulating hormone (TSH), fT4 and fT3 and in males follicle-stimulating hormone (FSH), luteinizing hormone (LH) and total testosterone were analysed as well as parameters of hypoxemia, such as SaO2 and paO2 at 550 m (baseline) (n = 40), during ascent at 4844 m (n = 38), 6022 m (n = 31) and 7050 m (n = 13), at 4844 m (n = 29) after acclimatization and after the expedition (n = 38). Correlation analysis of hormone concentrations with oxygen parameters and with altitude revealed statistical association in most cases only with altitude. Adrenal, thyroid and gonadal axes were affected by increasing altitude. Adrenal axis and prolactin were first supressed at 4844 m and then activated with increasing altitude; thyroid and gonadal axes were directly activated or suppressed respectively with increasing altitude. Acclimatisation at 4844 m led to normalization of adrenal and gonadal but not of thyroid axes. In conclusion, acclimatization partly leads to a normalization of the adrenal, thyroid and gonadal axes at around 5000 m. However, at higher altitude, endocrine dysregulation is pronounced and might contribute to the physical degradation found at high altitude.
Collapse
Affiliation(s)
- M von Wolff
- Division of Gynaecological Endocrinology and Reproductive MedicineUniversity Women’s Hospital, Bern University Hospital, University of Bern, Bern, Switzerland
- Correspondence should be addressed to M von Wolff:
| | - C T Nakas
- University Institute of Clinical ChemistryInselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Laboratory of BiometryUniversity of Thessaly, Volos, Greece
| | - M Tobler
- Division of Gynaecological Endocrinology and Reproductive MedicineUniversity Women’s Hospital, Bern University Hospital, University of Bern, Bern, Switzerland
- Division of PneumologyInselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - T M Merz
- Division of Intensive Care MedicineInselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - M P Hilty
- Intensive Care UnitUniversity Hospital, Zurich, Switzerland
| | - J D Veldhuis
- Endocrine Research UnitDepartment of Internal Medicine, Mayo School of Graduate Medical Education, Centre for Translational Science Activities, Mayo Clinic, Rochester, New York, USA
| | - A R Huber
- Centre for Laboratory MedicineCantonal Hospital, Aarau, Switzerland
| | - J Pichler Hefti
- Division of PneumologyInselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| |
Collapse
|
20
|
Barts N, Greenway R, Passow CN, Arias-Rodriguez L, Kelley JL, Tobler M. Molecular evolution and expression of oxygen transport genes in livebearing fishes (Poeciliidae) from hydrogen sulfide rich springs. Genome 2018; 61:273-286. [DOI: 10.1139/gen-2017-0051] [Citation(s) in RCA: 12] [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] [Indexed: 12/30/2022]
Abstract
Hydrogen sulfide (H2S) is a natural toxicant in some aquatic environments that has diverse molecular targets. It binds to oxygen transport proteins, rendering them non-functional by reducing oxygen-binding affinity. Hence, organisms permanently inhabiting H2S-rich environments are predicted to exhibit adaptive modifications to compensate for the reduced capacity to transport oxygen. We investigated 10 lineages of fish of the family Poeciliidae that have colonized freshwater springs rich in H2S—along with related lineages from non-sulfidic environments—to test hypotheses about the expression and evolution of oxygen transport genes in a phylogenetic context. We predicted shifts in the expression of and signatures of positive selection on oxygen transport genes upon colonization of H2S-rich habitats. Our analyses indicated significant shifts in gene expression for multiple hemoglobin genes in lineages that have colonized H2S-rich environments, and three hemoglobin genes exhibited relaxed selection in sulfidic compared to non-sulfidic lineages. However, neither changes in gene expression nor signatures of selection were consistent among all lineages in H2S-rich environments. Oxygen transport genes may consequently be predictable targets of selection during adaptation to sulfidic environments, but changes in gene expression and molecular evolution of oxygen transport genes in H2S-rich environments are not necessarily repeatable across replicated lineages.
Collapse
Affiliation(s)
- Nicholas Barts
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| | - Ryan Greenway
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| | - Courtney N. Passow
- Ecology, Evolution and Behavior, University of Minnesota St. Paul, 205 Cargill Building, St. Paul, MN 55108, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), C.P. 86150, Villahermosa, Tabasco, México
| | - Joanna L. Kelley
- Department of Biological Sciences, Washington State University, 431 Heald Hall, Pullman, WA 99164, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| |
Collapse
|
21
|
Culumber ZW, Tobler M. Correlated evolution of thermal niches and functional physiology in tropical freshwater fishes. J Evol Biol 2018; 31:722-734. [DOI: 10.1111/jeb.13260] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/13/2018] [Accepted: 02/23/2018] [Indexed: 11/30/2022]
Affiliation(s)
| | - Michael Tobler
- Division of Biology Kansas State University Manhattan KS USA
| |
Collapse
|
22
|
Tobler M, Kelley JL, Plath M, Riesch R. Extreme environments and the origins of biodiversity: Adaptation and speciation in sulphide spring fishes. Mol Ecol 2018; 27:843-859. [DOI: 10.1111/mec.14497] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Michael Tobler
- Division of Biology Kansas State University Manhattan KS USA
| | - Joanna L. Kelley
- School of Biological Sciences Washington State University Pullman WA USA
| | - Martin Plath
- Shaanxi Key Laboratory of Molecular Biology for Agriculture College of Animal Science and Technology Northwest A&F University Yangling Shaanxi China
| | - Rüdiger Riesch
- School of Biological Sciences Centre for Ecology, Evolution and Behaviour Royal Holloway University of London Egham Surrey UK
| |
Collapse
|
23
|
Abstract
Convergent evolution in organismal function can arise from nonconvergent changes in traits that contribute to that function. Theory predicts that low resource availability and high maintenance costs in extreme environments select for reductions in organismal energy demands, which could be attained through modifications of body size or metabolic rate. We tested for convergence in energy demands and underlying traits by investigating livebearing fish (genus Poecilia) that have repeatedly colonized toxic, hydrogen sulphide-rich springs. We quantified variation in body size and routine metabolism across replicated sulphidic and non-sulphidic populations in nature, modelled total organismal energy demands, and conducted a common-garden experiment to test whether population differences had a genetic basis. Sulphidic populations generally exhibited smaller body sizes and lower routine metabolic rates compared to non-sulphidic populations, which together caused significant reductions in total organismal energy demands in extremophile populations. Although both mechanisms contributed to variation in organismal energy demands, variance partitioning indicated reductions of body size overall had a greater effect than reductions of routine metabolism. Finally, population differences in routine metabolism documented in natural populations were maintained in common-garden reared individuals, indicating evolved differences. In combination with other studies, these results suggest that reductions in energy demands may represent a common theme in adaptation to physiochemical stressors. Selection for reduced energy demand may particularly affect body size, which has implications for life history evolution in extreme environments.
Collapse
Affiliation(s)
- Courtney N. Passow
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| |
Collapse
|
24
|
Passow CN, Henpita C, Shaw JH, Quackenbush CR, Warren WC, Schartl M, Arias-Rodriguez L, Kelley JL, Tobler M. The roles of plasticity and evolutionary change in shaping gene expression variation in natural populations of extremophile fish. Mol Ecol 2017; 26:6384-6399. [PMID: 28926156 DOI: 10.1111/mec.14360] [Citation(s) in RCA: 23] [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: 11/15/2016] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 12/22/2022]
Abstract
The notorious plasticity of gene expression responses and the complexity of environmental gradients complicate the identification of adaptive differences in gene regulation among populations. We combined transcriptome analyses in nature with common-garden and exposure experiments to establish cause-effect relationships between the presence of a physiochemical stressor and expression differences, as well as to test how evolutionary change and plasticity interact to shape gene expression variation in natural systems. We studied two evolutionarily independent population pairs of an extremophile fish (Poecilia mexicana) living in toxic, hydrogen sulphide (H2 S)-rich springs and adjacent nontoxic habitats and assessed genomewide expression patterns of wild-caught and common-garden-raised individuals exposed to different concentrations of H2 S. We found that 7.7% of genes that were differentially expressed between sulphidic and nonsulphidic ecotypes remained differentially expressed in the laboratory, indicating that sources of selection other than H2 S-or plastic responses to other environmental factors-contribute substantially to gene expression patterns observed in the wild. Concordantly differentially expressed genes in the wild and the laboratory were primarily associated with H2 S detoxification, sulphur processing and metabolic physiology. While shared, ancestral plasticity played a minor role in shaping gene expression variation observed in nature, we documented evidence for evolved population differences in the constitutive expression as well as the H2 S inducibility of candidate genes. Mechanisms underlying gene expression variation also varied substantially across the two ecotype pairs. These results provide a springboard for studying evolutionary modifications of gene regulatory mechanisms that underlie expression variation in locally adapted populations.
Collapse
Affiliation(s)
| | - Chathurika Henpita
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Jennifer H Shaw
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Corey R Quackenbush
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Wesley C Warren
- McDonnell Genome Institute, Washington University, St. Louis, MO, USA
| | - Manfred Schartl
- Physiological Chemistry, University of Würzburg, Würzburg, Germany.,Comprehensive Cancer Center Mainfranken, University Clinic Würzburg, Würzburg, Germany.,Hagler Institute for Advanced Studies and Department of Biology, Texas A&M University, College Station, TX, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, México
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| |
Collapse
|
25
|
Brown AP, Greenway R, Morgan S, Quackenbush CR, Giordani L, Arias-Rodriguez L, Tobler M, Kelley JL. Genome-scale data reveal that endemic Poecilia populations from small sulphidic springs display no evidence of inbreeding. Mol Ecol 2017; 26:4920-4934. [PMID: 28731545 DOI: 10.1111/mec.14249] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 11/22/2016] [Revised: 04/04/2017] [Accepted: 06/21/2017] [Indexed: 12/27/2022]
Abstract
Populations with limited ranges can be highly vulnerable to changes in their environment and are, thus, of high conservation concern. Populations that experience human-induced range reductions are often highly inbred and lack genetic diversity, but it is unknown whether this is also the case for populations with naturally small ranges. The fishes Poecilia sulphuraria (listed as critically endangered) and Poecilia thermalis, which are endemic to small hydrogen sulphide-rich springs in southern Mexico, are examples of such populations with inherently small habitats. We used geometric morphometrics and population genetics to quantify phenotypic and genetic variation within and among two populations of P. sulphuraria and one population of P. thermalis. Principal component analyses revealed phenotypic and genetic differences among the populations. Evidence for inbreeding was low compared to populations that have undergone habitat reduction. The genetic data were also used to infer the demographic history of these populations to obtain estimates for effective population sizes and migration rates. Effective population sizes were large given the small habitats of these populations. Our results imply that these three endemic extremophile populations should each be considered separately for conservation purposes. Additionally, this study suggests that populations in naturally small habitats may have lower rates of inbreeding and higher genetic diversity than expected, and therefore may be better equipped to handle environmental perturbations than anticipated. We caution, however, that the inferred lack of inbreeding and the large effective population sizes could potentially be a result of colonization by genetically diverse ancestors.
Collapse
Affiliation(s)
- Anthony P Brown
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Ryan Greenway
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Samuel Morgan
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Corey R Quackenbush
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | | | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), Villahermosa, Tabasco, México
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| |
Collapse
|
26
|
Passow CN, Brown AP, Arias-Rodriguez L, Yee MC, Sockell A, Schartl M, Warren WC, Bustamante C, Kelley JL, Tobler M. Complexities of gene expression patterns in natural populations of an extremophile fish (Poecilia mexicana, Poeciliidae). Mol Ecol 2017; 26:4211-4225. [PMID: 28598519 DOI: 10.1111/mec.14198] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 01/30/2017] [Revised: 05/18/2017] [Accepted: 05/24/2017] [Indexed: 12/31/2022]
Abstract
Variation in gene expression can provide insights into organismal responses to environmental stress and physiological mechanisms mediating adaptation to habitats with contrasting environmental conditions. We performed an RNA-sequencing experiment to quantify gene expression patterns in fish adapted to habitats with different combinations of environmental stressors, including the presence of toxic hydrogen sulphide (H2 S) and the absence of light in caves. We specifically asked how gene expression varies among populations living in different habitats, whether population differences were consistent among organs, and whether there is evidence for shared expression responses in populations exposed to the same stressors. We analysed organ-specific transcriptome-wide data from four ecotypes of Poecilia mexicana (nonsulphidic surface, sulphidic surface, nonsulphidic cave and sulphidic cave). The majority of variation in gene expression was correlated with organ type, and the presence of specific environmental stressors elicited unique expression differences among organs. Shared patterns of gene expression between populations exposed to the same environmental stressors increased with levels of organismal organization (from transcript to gene to physiological pathway). In addition, shared patterns of gene expression were more common between populations from sulphidic than populations from cave habitats, potentially indicating that physiochemical stressors with clear biochemical consequences can constrain the diversity of adaptive solutions that mitigate their adverse effects. Overall, our analyses provided insights into transcriptional variation in a unique system, in which adaptation to H2 S and darkness coincide. Functional annotations of differentially expressed genes provide a springboard for investigating physiological mechanisms putatively underlying adaptation to extreme environments.
Collapse
Affiliation(s)
| | - Anthony P Brown
- Department of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México
| | - Muh-Ching Yee
- Department of Genetics, Stanford University, Stanford, CA, USA
| | | | - Manfred Schartl
- Physiological Chemistry, Biozentrum, University of Würzburg, Würzburg, Germany.,Comprehensive Cancer Center Mainfranken, University Clinic Würzburg, Würzburg, Germany.,Texas A&M Institute for Advanced Study and Department of Biology, Texas A&M University, College Station, TX, USA
| | - Wesley C Warren
- McDonnell Genome Institute, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Joanna L Kelley
- Department of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, USA
| |
Collapse
|
27
|
Husemann M, Tobler M, McCauley C, Ding B, Danley PD. Body shape differences in a pair of closely related Malawi cichlids and their hybrids: Effects of genetic variation, phenotypic plasticity, and transgressive segregation. Ecol Evol 2017. [PMID: 28649345 PMCID: PMC5478046 DOI: 10.1002/ece3.2823] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [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] [Indexed: 12/20/2022] Open
Abstract
Phenotypic differences may have genetic and plastic components. Here, we investigated the contributions of both for differences in body shape in two species of Lake Malawi cichlids using wild-caught specimens and a common garden experiment. We further hybridized the two species to investigate the mode of gene action influencing body shape differences and to examine the potential for transgressive segregation. We found that body shape differences between the two species observed in the field are maintained after more than 10 generations in a standardized environment. Nonetheless, both species experienced similar changes in the laboratory environment. Our hybrid cross experiment confirmed that substantial variation in body shape appears to be genetically determined. The data further suggest that the underlying mode of gene action is complex and cannot be explained by simple additive or additive-dominance models. Transgressive phenotypes were found in the hybrid generations, as hybrids occupied significantly more morphospace than both parentals combined. Further, the body shapes of transgressive individuals resemble the body shapes observed in other Lake Malawi rock-dwelling genera. Our findings indicate that body shape can respond to selection immediately, through plasticity, and over longer timescales through adaptation. In addition, our results suggest that hybridization may have played an important role in the diversification of Lake Malawi cichlids through creating new phenotypic variation.
Collapse
Affiliation(s)
- Martin Husemann
- Centrum für Naturkunde University of Hamburg Hamburg Germany.,Biology Department Baylor University Waco TX USA
| | - Michael Tobler
- Division of Biology Kansas State University Manhattan KS USA
| | - Cagney McCauley
- Biology Department Baylor University Waco TX USA.,Department of Biological Sciences Institute of Applied Sciences University of North Texas 282 Cr 332 Rosebud Denton TX USA
| | - Baoqing Ding
- Biology Department Baylor University Waco TX USA.,Department of Ecology and Evolutionary Biology University of Connecticut Storrs CT USA
| | | |
Collapse
|
28
|
Griffith SC, Crino OL, Andrew SC, Nomano FY, Adkins-Regan E, Alonso-Alvarez C, Bailey IE, Bittner SS, Bolton PE, Boner W, Boogert N, Boucaud ICA, Briga M, Buchanan KL, Caspers BA, Cichoń M, Clayton DF, Derégnaucourt S, Forstmeier W, Guillette LM, Hartley IR, Healy SD, Hill DL, Holveck MJ, Hurley LL, Ihle M, Tobias Krause E, Mainwaring MC, Marasco V, Mariette MM, Martin-Wintle MS, McCowan LSC, McMahon M, Monaghan P, Nager RG, Naguib M, Nord A, Potvin DA, Prior NH, Riebel K, Romero-Haro AA, Royle NJ, Rutkowska J, Schuett W, Swaddle JP, Tobler M, Trompf L, Varian-Ramos CW, Vignal C, Villain AS, Williams TD. Variation in Reproductive Success Across Captive Populations: Methodological Differences, Potential Biases and Opportunities. Ethology 2016. [DOI: 10.1111/eth.12576] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Simon C. Griffith
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Ondi L. Crino
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Samuel C. Andrew
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Fumiaki Y. Nomano
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Elizabeth Adkins-Regan
- Department of Psychology and Department of Neurobiology and Behavior; Cornell University; Ithaca NY USA
| | - Carlos Alonso-Alvarez
- Instituto de Investigación en Recursos Cinegéticos (IREC) - CSIC-UCLM-JCCM; Ciudad Real Spain
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales - CSIC; Madrid Spain
| | - Ida E. Bailey
- School of Biology; University of St Andrews; St Andrews, Fife UK
| | | | - Peri E. Bolton
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Winnie Boner
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - Neeltje Boogert
- School of Psychology; University of St Andrews; St Andrews, Fife UK
| | - Ingrid C. A. Boucaud
- CNRS UMR 9197 NeuroPSI/ENES; Université de Lyon/Saint-Etienne; Saint-Etienne France
| | - Michael Briga
- Behavioural Biology; University of Groningen; Groningen The Netherlands
| | | | | | - Mariusz Cichoń
- Institute of Environmental Sciences; Jagiellonian University; Cracow Poland
| | - David F. Clayton
- Department of Biological and Experimental Psychology; Queen Mary University of London; London UK
| | | | - Wolfgang Forstmeier
- Department of Behavioural Ecology and Evolutionary Genetics; Max Planck Institute for Ornithology; Seewiesen Germany
| | | | - Ian R. Hartley
- Lancaster Environment Centre; Lancaster University; Lancaster UK
| | - Susan D. Healy
- School of Biology; University of St Andrews; St Andrews, Fife UK
| | - Davina L. Hill
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - Marie-Jeanne Holveck
- Institute of Biology; University of Leiden; Leiden The Netherlands
- Biodiversity Research Centre; Earth and Life Institute; Université Catholique de Louvain (UCL); Louvain-la-Neuve Belgium
| | - Laura L. Hurley
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Malika Ihle
- Department of Behavioural Ecology and Evolutionary Genetics; Max Planck Institute for Ornithology; Seewiesen Germany
| | - E. Tobias Krause
- Department of Animal Behaviour; Bielefeld University; Bielefeld Germany
- Institute of Animal Welfare and Animal Husbandry; Friedrich-Loeffler-Institut; Celle Germany
| | - Mark C. Mainwaring
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
- Lancaster Environment Centre; Lancaster University; Lancaster UK
| | - Valeria Marasco
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - Mylene M. Mariette
- CNRS UMR 9197 NeuroPSI/ENES; Université de Lyon/Saint-Etienne; Saint-Etienne France
- School of Life and Environmental Sciences; Deakin University; Geelong VIC Australia
| | - Meghan S. Martin-Wintle
- Conservation and Research Department; PDXWildlife; Portland OR USA
- Applied Animal Ecology; Institute for Conservation Research; San Diego Zoo Global; Escondido CA USA
| | - Luke S. C. McCowan
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Maeve McMahon
- Department of Biological and Experimental Psychology; Queen Mary University of London; London UK
| | - Pat Monaghan
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - Ruedi G. Nager
- Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow UK
| | - Marc Naguib
- Behavioural Ecology Group; Department of Animal Sciences; Wageningen The Netherlands
| | - Andreas Nord
- Department of Biology; Lund University; Lund Sweden
- Department of Arctic and Marine Biology; University of Tromsø; Tromsø Norway
| | - Dominique A. Potvin
- Advanced Facility for Avian Research; University of Western Ontario; London ON Canada
| | - Nora H. Prior
- Zoology Department; University of British Columbia; Vancouver BC Canada
| | - Katharina Riebel
- Lancaster Environment Centre; Lancaster University; Lancaster UK
| | - Ana A. Romero-Haro
- Instituto de Investigación en Recursos Cinegéticos (IREC) - CSIC-UCLM-JCCM; Ciudad Real Spain
| | - Nick J. Royle
- Centre for Ecology and Conservation; University of Exeter; Penryn UK
| | - Joanna Rutkowska
- Institute of Environmental Sciences; Jagiellonian University; Cracow Poland
| | - Wiebke Schuett
- Zoological Institute; University of Hamburg; Hamburg Germany
| | - John P. Swaddle
- Biology Department; Institute for Integrative Bird Behaviour Studies; The College of William and Mary; Williamsburg VA USA
| | | | - Larissa Trompf
- Department of Biological Sciences; Macquarie University; Sydney NSW Australia
| | - Claire W. Varian-Ramos
- Biology Department; Institute for Integrative Bird Behaviour Studies; The College of William and Mary; Williamsburg VA USA
| | - Clémentine Vignal
- CNRS UMR 9197 NeuroPSI/ENES; Université de Lyon/Saint-Etienne; Saint-Etienne France
| | - Avelyne S. Villain
- CNRS UMR 9197 NeuroPSI/ENES; Université de Lyon/Saint-Etienne; Saint-Etienne France
| | - Tony D. Williams
- Department of Biological Sciences; Simon Fraser University; Burnaby BC Canada
| |
Collapse
|
29
|
Affiliation(s)
- Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| | - Zachary W. Culumber
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| |
Collapse
|
30
|
Greenway R, Drexler S, Arias‐Rodriguez L, Tobler M. Adaptive, but not condition‐dependent, body shape differences contribute to assortative mating preferences during ecological speciation. Evolution 2016; 70:2809-2822. [DOI: 10.1111/evo.13087] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 02/05/2023]
Affiliation(s)
- Ryan Greenway
- Division of Biology Kansas State University Manhattan Kansas 66506
| | - Shannon Drexler
- Department of Biology University of Wisconsin‐Platteville 1 University Plaza Platteville Wisconsin 53818
| | - Lenin Arias‐Rodriguez
- División Académica de Ciencias Biológicas Universidad Juárez Autónoma de Tabasco Villahermosa Tabasco México
| | - Michael Tobler
- Division of Biology Kansas State University Manhattan Kansas 66506
| |
Collapse
|
31
|
Tobler M, Passow CN, Greenway R, Kelley JL, Shaw JH. The Evolutionary Ecology of Animals Inhabiting Hydrogen Sulfide–Rich Environments. Annu Rev Ecol Evol Syst 2016. [DOI: 10.1146/annurev-ecolsys-121415-032418] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hydrogen sulfide (H2S) is a respiratory toxicant that creates extreme environments tolerated by few organisms. H2S is also produced endogenously by metazoans and plays a role in cell signaling. The mechanisms of H2S toxicity and its physiological functions serve as a basis to discuss the multifarious strategies that allow animals to survive in H2S-rich environments. Despite their toxicity, H2S-rich environments also provide ecological opportunities, and complex selective regimes of covarying abiotic and biotic factors drive trait evolution in organisms inhabiting H2S-rich environments. Furthermore, adaptation to H2S-rich environments can drive speciation, giving rise to biodiversity hot spots with high levels of endemism in deep-sea hydrothermal vents, cold seeps, and freshwater sulfide springs. The diversity of H2S-rich environments and their inhabitants provides ideal systems for comparative studies of the effects of a clear-cut source of selection across vast geographic and phylogenetic scales, ultimately informing our understanding of how environmental stressors affect ecological and evolutionary processes.
Collapse
Affiliation(s)
- Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas 66506
| | | | - Ryan Greenway
- Division of Biology, Kansas State University, Manhattan, Kansas 66506
| | - Joanna L. Kelley
- School of Biological Sciences, Washington State University, Pullman, Washington 99164
| | - Jennifer H. Shaw
- Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma 74078
| |
Collapse
|
32
|
Voelker G, Tobler M, Prestridge HL, Duijm E, Groenenberg D, Hutchinson MR, Martin AD, Nieman A, Roselaar CS, Huntley JW. Three new species of Stiphrornis (Aves: Muscicapidae) from the Afro-tropics, with a molecular phylogenetic assessment of the genus. SYST BIODIVERS 2016. [DOI: 10.1080/14772000.2016.1226978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Gary Voelker
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Heather L. Prestridge
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Elza Duijm
- Naturalis Biodiversity Center, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Dick Groenenberg
- Naturalis Biodiversity Center, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Mark R. Hutchinson
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Alyssa D. Martin
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Aline Nieman
- Naturalis Biodiversity Center, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Cees S. Roselaar
- Naturalis Biodiversity Center, Vertebrate Department, PO Box 9517, 2300 RA Leiden, the Netherlands
| | - Jerry W. Huntley
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| |
Collapse
|
33
|
Bagley JC, Matamoros WA, McMahan CD, Tobler M, Chakrabarty P, Johnson JB. Phylogeography and species delimitation in convict cichlids (Cichlidae:Amatitlania): implications for taxonomy and Plio-Pleistocene evolutionary history in Central America. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12845] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Justin C. Bagley
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
| | - Wilfredo A. Matamoros
- Facultad de Ciencias Biológicas, Museo de Zoología; Colección de Ictiología; Universidad de Ciencias y Artes de Chiapas; CP 29039 Tuxtla Gutierrez Chiapas México
| | - Caleb D. McMahan
- Museum of Natural Science (Ichthyology); Department of Biological Sciences; Louisiana State University; Baton Rouge LA 70803 USA
- The Field Museum of Natural History; 1400 S. Lake Shore Drive Chicago IL 60605 USA
| | - Michael Tobler
- Division of Biology; Kansas State University; Manhattan KS 66506 USA
| | - Prosanta Chakrabarty
- Museum of Natural Science (Ichthyology); Department of Biological Sciences; Louisiana State University; Baton Rouge LA 70803 USA
| | - Jerald B. Johnson
- Evolutionary Ecology Laboratories; Department of Biology; Brigham Young University; Provo UT 84602 USA
- Monte L. Bean Life Science Museum; Brigham Young University; Provo UT 84602 USA
| |
Collapse
|
34
|
Palacios M, Voelker G, Arias Rodriguez L, Mateos M, Tobler M. Phylogenetic analyses of the subgenus Mollienesia (Poecilia, Poeciliidae, Teleostei) reveal taxonomic inconsistencies, cryptic biodiversity, and spatio-temporal aspects of diversification in Middle America. Mol Phylogenet Evol 2016; 103:230-244. [PMID: 27472959 DOI: 10.1016/j.ympev.2016.07.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 09/14/2015] [Revised: 07/16/2016] [Accepted: 07/22/2016] [Indexed: 01/19/2023]
Abstract
The subgenus Mollienesia is a diverse group of freshwater fishes, including species that have served as important models across multiple biological disciplines. Nonetheless, the taxonomic history of this group has been conflictive and convoluted, in part because the evolutionary relationships have not been rigorously resolved. We conducted a comprehensive molecular phylogenetic analysis of the subgenus Mollienesia to identify taxonomic discrepancies and potentially identify undescribed species, estimate ancestral areas of origin and estimate dates of divergence, as well as explore biogeographical patterns. Our findings confirm the presence of three main clades composed of the P. latipinna, P. sphenops, and P. mexicana species complexes. Unlike previously hypothesized morphology-based analyses, species found on the Caribbean Islands are not part of Mollienesia, but are more closely related to species of the subgenus Limia. Our study also revealed several taxonomic inconsistencies and distinct lineages in the P. mexicana species complex that may represent undescribed species. The diversity in the subgenus Mollienesia is a result of dynamic geologic activity leading to vicariant events, dispersal across geologic blocks, and ecological speciation.
Collapse
Affiliation(s)
- Maura Palacios
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, TX 77843, USA.
| | - Gary Voelker
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, TX 77843, USA
| | - Lenin Arias Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), C.P. 86150 Villahermosa, Tabasco, Mexico
| | - Mariana Mateos
- Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, TX 77843, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506, USA
| |
Collapse
|
35
|
Fitzgerald DB, Tobler M, Winemiller KO. From richer to poorer: successful invasion by freshwater fishes depends on species richness of donor and recipient basins. Glob Chang Biol 2016; 22:2440-2450. [PMID: 26582547 DOI: 10.1111/gcb.13165] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 07/07/2015] [Accepted: 11/09/2015] [Indexed: 06/05/2023]
Abstract
Evidence for the theory of biotic resistance is equivocal, with experiments often finding a negative relationship between invasion success and native species richness, and large-scale comparative studies finding a positive relationship. Biotic resistance derives from local species interactions, yet global and regional studies often analyze data at coarse spatial grains. In addition, differences in competitive environments across regions may confound tests of biotic resistance based solely on native species richness of the invaded community. Using global and regional data sets for fishes in river and stream reaches, we ask two questions: (1) does a negative relationship exist between native and non-native species richness and (2) do non-native species originate from higher diversity systems. A negative relationship between native and non-native species richness in local assemblages was found at the global scale, while regional patterns revealed the opposite trend. At both spatial scales, however, nearly all non-native species originated from river basins with higher native species richness than the basin of the invaded community. Together, these findings imply that coevolved ecological interactions in species-rich systems inhibit establishment of generalist non-native species from less diverse communities. Consideration of both the ecological and evolutionary aspects of community assembly is critical to understanding invasion patterns. Distinct evolutionary histories in different regions strongly influence invasion of intact communities that are relatively unimpacted by human actions, and may explain the conflicting relationship between native and non-native species richness found at different spatial scales.
Collapse
Affiliation(s)
- Daniel B Fitzgerald
- Program in Ecology and Evolutionary Biology and Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, 77843-2258, USA
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Kirk O Winemiller
- Program in Ecology and Evolutionary Biology and Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, 77843-2258, USA
| |
Collapse
|
36
|
Riesch R, Tobler M, Lerp H, Jourdan J, Doumas T, Nosil P, Langerhans RB, Plath M. Extremophile Poeciliidae: multivariate insights into the complexity of speciation along replicated ecological gradients. BMC Evol Biol 2016; 16:136. [PMID: 27334284 PMCID: PMC4918007 DOI: 10.1186/s12862-016-0705-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [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: 04/18/2016] [Accepted: 06/08/2016] [Indexed: 11/30/2022] Open
Abstract
Background Replicate population pairs that diverge in response to similar selective regimes allow for an investigation of (a) whether phenotypic traits diverge in a similar and predictable fashion, (b) whether there is gradual variation in phenotypic divergence reflecting variation in the strength of natural selection among populations, (c) whether the extent of this divergence is correlated between multiple character suites (i.e., concerted evolution), and (d) whether gradual variation in phenotypic divergence predicts the degree of reproductive isolation, pointing towards a role for adaptation as a driver of (ecological) speciation. Here, we use poeciliid fishes of the genera Gambusia and Poecilia that have repeatedly evolved extremophile lineages able to tolerate high and sustained levels of toxic hydrogen sulfide (H2S) to answer these questions. Results We investigated evolutionary divergence in response to H2S in Gambusia spp. (and to a lesser extent Poecilia spp.) using a multivariate approach considering the interplay of life history, body shape, and population genetics (nuclear miscrosatellites to infer population genetic differentiation as a proxy for reproductive isolation). We uncovered both shared and unique patterns of evolution: most extremophile Gambusia predictably evolved larger heads and offspring size, matching a priori predictions for adaptation to sulfidic waters, while variation in adult life histories was idiosyncratic. When investigating patterns for both genera (Gambusia and Poecilia), we found that divergence in offspring-related life histories and body shape were positively correlated across populations, but evidence for individual-level associations between the two character suites was limited, suggesting that genetic linkage, developmental interdependencies, or pleiotropic effects do not explain patterns of concerted evolution. We further found that phenotypic divergence was positively correlated with both environmental H2S-concentration and neutral genetic differentiation (a proxy for gene flow). Conclusions Our results suggest that higher toxicity exerts stronger selection, and that divergent selection appears to constrain gene flow, supporting a scenario of ecological speciation. Nonetheless, progress toward ecological speciation was variable, partially reflecting variation in the strength of divergent selection, highlighting the complexity of selective regimes even in natural systems that are seemingly governed by a single, strong selective agent. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0705-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Rüdiger Riesch
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK. .,Department of Biological Sciences & W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Labs, Raleigh, NC, 27695-7617, USA.
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS, 66506, USA
| | - Hannes Lerp
- Natural History Collections, Museum Wiesbaden, Friedrich-Ebert-Allee 2, 65185, Wiesbaden, Germany
| | - Jonas Jourdan
- J. W. Goethe-University Frankfurt/M., Evolutionary Ecology Group, Max-von-Laue Str. 13, 60438, Frankfurt a. M., Germany
| | - Tess Doumas
- Department of Biology and Biochemistry, University of Houston, 4800 Calhoun Rd., Houston, TX, 77004, USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - R Brian Langerhans
- Department of Biological Sciences & W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Labs, Raleigh, NC, 27695-7617, USA
| | - Martin Plath
- College of Animal Science and Technology, Northwest A&F University, Xinong Road 22, Yangling, 712100, People's Republic of China
| |
Collapse
|
37
|
Schulz‐Mirbach T, Eifert C, Riesch R, Farnworth MS, Zimmer C, Bierbach D, Klaus S, Tobler M, Streit B, Indy JR, Arias‐Rodriguez L, Plath M. Toxic hydrogen sulphide shapes brain anatomy: a comparative study of sulphide‐adapted ecotypes in the
Poecilia mexicana
complex. J Zool (1987) 2016. [DOI: 10.1111/jzo.12366] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- T. Schulz‐Mirbach
- Department Biology II Ludwig‐Maximilians‐University Munich Planegg‐Martinsried Germany
| | - C. Eifert
- Ecology and Evolution J. W. Goethe University Frankfurt Frankfurt am Main Germany
| | - R. Riesch
- School of Biological Sciences Royal Holloway University of London Egham UK
| | - M. S. Farnworth
- Göttingen Center for Molecular Biosciences Georg‐August‐University Göttingen Göttingen Germany
| | - C. Zimmer
- Ecology and Evolution J. W. Goethe University Frankfurt Frankfurt am Main Germany
| | - D. Bierbach
- Department of Biology and Ecology of Fishes Leibniz‐Institute of Freshwater Ecology and Inland Fisheries Berlin Germany
| | - S. Klaus
- Ecology and Evolution J. W. Goethe University Frankfurt Frankfurt am Main Germany
| | - M. Tobler
- Division of Biology Kansas State University Manhattan KS USA
| | - B. Streit
- Ecology and Evolution J. W. Goethe University Frankfurt Frankfurt am Main Germany
| | - J. R. Indy
- División Académica de Ciencias Biológicas Universidad Juárez Autónoma de Tabasco (UJAT) Villahermosa Tabasco México
| | - L. Arias‐Rodriguez
- División Académica de Ciencias Biológicas Universidad Juárez Autónoma de Tabasco (UJAT) Villahermosa Tabasco México
| | - M. Plath
- College of Animal Science and Technology Northwest A&F University Yangling China
| |
Collapse
|
38
|
Culumber ZW, Tobler M. Ecological divergence and conservatism: spatiotemporal patterns of niche evolution in a genus of livebearing fishes (Poeciliidae: Xiphophorus). BMC Evol Biol 2016; 16:44. [PMID: 26895994 PMCID: PMC4761163 DOI: 10.1186/s12862-016-0593-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [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] [Received: 07/02/2015] [Accepted: 01/13/2016] [Indexed: 01/23/2023] Open
Abstract
Background Ecological factors often have a strong impact on spatiotemporal patterns of biodiversity. The integration of spatial ecology and phylogenetics allows for rigorous tests of whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence. We address this question in a genus of livebearing fishes for which the role of sexual selection in speciation has long been studied, but in which the potential role of ecological divergence during speciation has not been tested. Results By combining reconstruction of ancestral climate tolerances and disparity indices, we show that the earliest evolutionary split in Xiphophorus was associated with significant divergence for temperature variables. Niche evolution and present day niches were most closely associated with each species’ geographic distribution relative to a biogeographic barrier, the Trans-Mexican Volcanic Belt. Tests for similarity of the environmental backgrounds of closely related species suggested that the relative importance of niche conservatism and divergence during speciation varied among the primary clades of Xiphophorus. Closely related species in the two swordtail clades exhibited higher levels of niche overlap than expected given environmental background similarity indicative of niche conservatism. In contrast, almost all species of platyfish had significantly divergent niches compared to environmental backgrounds, which is indicative of niche divergence. Conclusion The results suggest that the relative importance of niche conservatism and divergence differed among the clades of Xiphophorus and that traits associated with niche evolution may be more evolutionarily labile in the platyfishes. Our results ultimately suggest that the taxonomic scale of tests for conservatism and divergence could greatly influence inferences of their relative importance in the speciation process. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0593-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Zachary W Culumber
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA.
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| |
Collapse
|
39
|
Kelley JL, Arias-Rodriguez L, Patacsil Martin D, Yee MC, Bustamante CD, Tobler M. Mechanisms Underlying Adaptation to Life in Hydrogen Sulfide-Rich Environments. Mol Biol Evol 2016; 33:1419-34. [PMID: 26861137 PMCID: PMC4868117 DOI: 10.1093/molbev/msw020] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [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] [Indexed: 01/07/2023] Open
Abstract
Hydrogen sulfide (H2S) is a potent toxicant interfering with oxidative phosphorylation in mitochondria and creating extreme environmental conditions in aquatic ecosystems. The mechanistic basis of adaptation to perpetual exposure to H2S remains poorly understood. We investigated evolutionarily independent lineages of livebearing fishes that have colonized and adapted to springs rich in H2S and compared their genome-wide gene expression patterns with closely related lineages from adjacent, nonsulfidic streams. Significant differences in gene expression were uncovered between all sulfidic and nonsulfidic population pairs. Variation in the number of differentially expressed genes among population pairs corresponded to differences in divergence times and rates of gene flow, which is consistent with neutral drift driving a substantial portion of gene expression variation among populations. Accordingly, there was little evidence for convergent evolution shaping large-scale gene expression patterns among independent sulfide spring populations. Nonetheless, we identified a small number of genes that was consistently differentially expressed in the same direction in all sulfidic and nonsulfidic population pairs. Functional annotation of shared differentially expressed genes indicated upregulation of genes associated with enzymatic H2S detoxification and transport of oxidized sulfur species, oxidative phosphorylation, energy metabolism, and pathways involved in responses to oxidative stress. Overall, our results suggest that modification of processes associated with H2S detoxification and toxicity likely complement each other to mediate elevated H2S tolerance in sulfide spring fishes. Our analyses allow for the development of novel hypotheses about biochemical and physiological mechanisms of adaptation to extreme environments.
Collapse
Affiliation(s)
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México
| | | | - Muh-Ching Yee
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA
| | | | | |
Collapse
|
40
|
Culumber ZW, Tobler M. Spatiotemporal environmental heterogeneity and the maintenance of the tailspot polymorphism in the variable platyfish (Xiphophorus variatus). Evolution 2016; 70:408-19. [PMID: 26748941 DOI: 10.1111/evo.12852] [Citation(s) in RCA: 5] [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: 08/18/2015] [Revised: 10/29/2015] [Accepted: 12/08/2015] [Indexed: 11/28/2022]
Abstract
Genetic variation is critical for adaptive evolution. Despite its importance, there is still limited evidence in support of some prominent theoretical models explaining the maintenance of genetic polymorphism within populations. We examined 84 populations of Xiphophorus variatus, a livebearing fish with a genetic polymorphism associated with physiological performance, to test: (1) whether niche differentiation explains broad-scale maintenance of polymorphism, (2) whether polymorphism is maintained among populations by local adaptation and migration, or (3) whether heterogeneity in explicit environmental variables could be linked to levels of polymorphism within populations. We found no evidence of climatic niche differentiation that could generate or maintain broad geographic variation in polymorphism. Subsequently, hierarchical partitioning of genetic richness and partial mantel tests revealed that 76% of the observed genetic richness was partitioned within populations with no effect of geographic distance on polymorphism. These results strongly suggest a lack of migration-selection balance in the maintenance of polymorphism, and model selection confirmed a significant relationship between environmental heterogeneity and genetic richness within populations. Few studies have demonstrated such effects at this scale, and additional studies in other taxa should examine the generality of gene-by-environment interactions across populations to better understand the dynamics and scale of balancing selection.
Collapse
Affiliation(s)
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, 66506
| |
Collapse
|
41
|
Speakman JR, Blount JD, Bronikowski AM, Buffenstein R, Isaksson C, Kirkwood TBL, Monaghan P, Ozanne SE, Beaulieu M, Briga M, Carr SK, Christensen LL, Cochemé HM, Cram DL, Dantzer B, Harper JM, Jurk D, King A, Noguera JC, Salin K, Sild E, Simons MJP, Smith S, Stier A, Tobler M, Vitikainen E, Peaker M, Selman C. Oxidative stress and life histories: unresolved issues and current needs. Ecol Evol 2015; 5:5745-57. [PMID: 26811750 PMCID: PMC4717350 DOI: 10.1002/ece3.1790] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 09/20/2015] [Indexed: 12/12/2022] Open
Abstract
Life‐history theory concerns the trade‐offs that mold the patterns of investment by animals between reproduction, growth, and survival. It is widely recognized that physiology plays a role in the mediation of life‐history trade‐offs, but the details remain obscure. As life‐history theory concerns aspects of investment in the soma that influence survival, understanding the physiological basis of life histories is related, but not identical, to understanding the process of aging. One idea from the field of aging that has gained considerable traction in the area of life histories is that life‐history trade‐offs may be mediated by free radical production and oxidative stress. We outline here developments in this field and summarize a number of important unresolved issues that may guide future research efforts. The issues are as follows. First, different tissues and macromolecular targets of oxidative stress respond differently during reproduction. The functional significance of these changes, however, remains uncertain. Consequently there is a need for studies that link oxidative stress measurements to functional outcomes, such as survival. Second, measurements of oxidative stress are often highly invasive or terminal. Terminal studies of oxidative stress in wild animals, where detailed life‐history information is available, cannot generally be performed without compromising the aims of the studies that generated the life‐history data. There is a need therefore for novel non‐invasive measurements of multi‐tissue oxidative stress. Third, laboratory studies provide unrivaled opportunities for experimental manipulation but may fail to expose the physiology underpinning life‐history effects, because of the benign laboratory environment. Fourth, the idea that oxidative stress might underlie life‐history trade‐offs does not make specific enough predictions that are amenable to testing. Moreover, there is a paucity of good alternative theoretical models on which contrasting predictions might be based. Fifth, there is an enormous diversity of life‐history variation to test the idea that oxidative stress may be a key mediator. So far we have only scratched the surface. Broadening the scope may reveal new strategies linked to the processes of oxidative damage and repair. Finally, understanding the trade‐offs in life histories and understanding the process of aging are related but not identical questions. Scientists inhabiting these two spheres of activity seldom collide, yet they have much to learn from each other.
Collapse
Affiliation(s)
- John R Speakman
- Institute of Biological and Environmental Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK; State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Jonathan D Blount
- Centre for Ecology and Conservation University of Exeter Penryn Campus Cornwall TR10 9FE UK
| | - Anne M Bronikowski
- Department of Ecology, Evolution and Organismal Biology Iowa State University 251 Bessey Hall Ames Iowa 50011
| | - Rochelle Buffenstein
- Physiology, Barshop Institute for Aging and Longevity Research UTHSCSA 15355 Lambda Drive San Antonio Texas 78245
| | - Caroline Isaksson
- Department of Biology Lund University Solvegatan 37 Lund 223 62 Sweden
| | - Tom B L Kirkwood
- The Newcastle University Institute for Ageing Institute for Cell & Molecular Biosciences Campus for Ageing and Vitality Newcastle upon Tyne NE4 5PL UK
| | - Pat Monaghan
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Graham Kerr Building Glasgow G12 8QQ UK
| | - Susan E Ozanne
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Level 4 Wellcome Trust-MRC Institute of Metabolic Science Addenbrooke's Hospital Cambridge CB2 0QQ UK
| | - Michaël Beaulieu
- Zoological Institute and Museum University of Greifswald Johann-Sebastian Bach Str. 11/12 Greifswald 17489 Germany
| | - Michael Briga
- Behavioral Biology University of Groningen Nijenborgh 7 Groningen 9747 AG The Netherlands
| | - Sarah K Carr
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Level 4 Wellcome Trust-MRC Institute of Metabolic Science Addenbrooke's Hospital Cambridge CB2 0QQ UK
| | - Louise L Christensen
- Institute of Biological and Environmental Sciences University of Aberdeen Tillydrone Avenue Aberdeen AB24 2TZ UK
| | - Helena M Cochemé
- MRC Clinical Sciences Centre Imperial College London Hammersmith Hospital Campus Du Cane Road London W12 0NN UK
| | - Dominic L Cram
- Department of Zoology University of Cambridge Cambridge CB2 3EJ UK
| | - Ben Dantzer
- Department of Psychology University of Michigan Ann Arbor Michigan 48109
| | - Jim M Harper
- Department of Biological Sciences Sam Houston State University 1900 Avenue I LDB 100B Huntsville Texas 77341
| | - Diana Jurk
- The Newcastle University Institute for Ageing Institute for Cell & Molecular Biosciences Campus for Ageing and Vitality Newcastle upon Tyne NE4 5PL UK
| | - Annette King
- The Newcastle University Institute for Ageing Institute for Cell & Molecular Biosciences Campus for Ageing and Vitality Newcastle upon Tyne NE4 5PL UK
| | - Jose C Noguera
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Graham Kerr Building Glasgow G12 8QQ UK
| | - Karine Salin
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Graham Kerr Building Glasgow G12 8QQ UK
| | - Elin Sild
- Department of Biology Lund University Solvegatan 37 Lund 223 62 Sweden
| | - Mirre J P Simons
- Department of Animal and Plant Sciences University of Sheffield Alfred Denny Building, Western Bank Sheffield S10 2TN UK
| | - Shona Smith
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Graham Kerr Building Glasgow G12 8QQ UK
| | - Antoine Stier
- Department Ecology, Physiology et Ethology University of Strasbourg - IPHC (UMR7178) 23, rue Becquerel Strasbourg 67087 France
| | - Michael Tobler
- Department of Biology Lund University Solvegatan 37 Lund 223 62 Sweden
| | - Emma Vitikainen
- Centre for Ecology and Conservation University of Exeter Penryn Campus Cornwall TR10 9FE UK
| | | | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Graham Kerr Building Glasgow G12 8QQ UK
| |
Collapse
|
42
|
Sköld-Chiriac S, Nord A, Tobler M, Nilsson JÅ, Hasselquist D. Body temperature changes during simulated bacterial infection in a songbird: fever at night and hypothermia during the day. ACTA ACUST UNITED AC 2015; 218:2961-9. [PMID: 26232416 DOI: 10.1242/jeb.122150] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [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: 03/12/2015] [Accepted: 07/17/2015] [Indexed: 01/01/2023]
Abstract
Although fever (a closely regulated increase in body temperature in response to infection) typically is beneficial, it is energetically costly and may induce detrimentally high body temperatures. This can increase the susceptibility to energetic bottlenecks and risks of overheating in some organisms. Accordingly, it could be particularly interesting to study fever in small birds, which have comparatively high metabolic rates and high, variable body temperatures. We therefore investigated two aspects of fever and other sickness behaviours (circadian variation, dose dependence) in a small songbird, the zebra finch. We injected lipopolysaccharide (LPS) at the beginning of either the day or the night, and subsequently monitored body temperature, body mass change and food intake for the duration of the response. We found pronounced circadian variation in the body temperature response to LPS injection, manifested by (dose-dependent) hypothermia during the day but fever at night. This resulted in body temperature during the peak response being relatively similar during the day and night. Day-to-night differences might be explained in the context of circadian variation in body temperature: songbirds have a high daytime body temperature that is augmented by substantial heat production peaks during activity. This might require a trade-off between the benefit of fever and the risk of overheating. In contrast, at night, when body temperature is typically lower and less variable, fever can be used to mitigate infection. We suggest that the change in body temperature during infection in small songbirds is context dependent and regulated to promote survival according to individual demands at the time of infection.
Collapse
Affiliation(s)
- Sandra Sköld-Chiriac
- Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden
| | - Andreas Nord
- Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden
| | - Michael Tobler
- Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden
| | - Jan-Åke Nilsson
- Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden
| | - Dennis Hasselquist
- Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden
| |
Collapse
|
43
|
Abstract
Immune system functioning and maintenance entails costs which may limit investment into other processes such as reproduction. Yet, the proximate mechanisms and ‘currencies’ mediating the costs of immune responses remain elusive. In vertebrates, up-regulation of the innate immune system is associated with rapid phagocytic production of pro-oxidant molecules (so-called ‘oxidative burst’ responses). Oxidative burst responses are intended to eliminate pathogens but may also constitute an immunopathological risk as they may induce oxidative damage to self cells. To minimize the risk of infection and, at the same time, damage to self, oxidative burst activity must be carefully balanced. The current levels of pro- and antioxidants (i.e. the individual oxidative state) is likely to be a critical factor affecting this balance, but this has not yet been evaluated. Here, we perform an experiment on wild-caught painted dragon lizards (Ctenophorus pictus) to examine how the strength of immune-stimulated oxidative burst responses of phagocytes in whole blood relates to individual oxidative status under control conditions and during an in vivo immune challenge with Escherichia coli lipopolysaccharide (LPS). Under control conditions, oxidative burst responses were not predicted by the oxidative status of the lizards. LPS-injected individuals showed a strong increase in pro-oxidant levels and a strong decrease in antioxidant levels compared to control individuals demonstrating a shift in the pro-/antioxidant balance. Oxidative burst responses in LPS-injected lizards were positively related to post-challenge extracellular pro-oxidants (reflecting the level of cell activation) and negatively related to pre-challenge levels of mitochondrial superoxide (suggesting an immunoregulatory effect of this pro-oxidant). LPS-challenged males had higher oxidative burst responses than females, and in females oxidative burst responses seemed to depend more strongly on antioxidant status than in males. Our results confirm the idea that oxidative state may constrain the activity of the innate immune system. These constraints may have important consequences for the way selection acts on pro-oxidant generating processes.
Collapse
Affiliation(s)
- Michael Tobler
- University of Sydney, School of Biological Sciences, Sydney, NSW, Australia
- Department of Biology, Lund University, Ecology Building, SE-223 62, Lund, Sweden
- * E-mail:
| | - Cissy Ballen
- University of Sydney, School of Biological Sciences, Sydney, NSW, Australia
| | - Mo Healey
- University of Sydney, School of Biological Sciences, Sydney, NSW, Australia
| | - Mark Wilson
- University of Wollongong, School of Biological Sciences, Wollongong, NSW, Australia
| | - Mats Olsson
- University of Sydney, School of Biological Sciences, Sydney, NSW, Australia
| |
Collapse
|
44
|
Shaw J, Henpita C, Tobler M. H
2
S‐tolerant Fish Differentially Express Genes and Modify Mitochondrial Function to Maintain H
2
S Homeostasis. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.640.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jennifer Shaw
- ZoologyOklahoma State UniversityStillwaterOklahomaUnited States
| | | | - Michael Tobler
- BiologyKansas State UniversityManhattanKansasUnited States
| |
Collapse
|
45
|
Passow CN, Greenway R, Arias-Rodriguez L, Jeyasingh PD, Tobler M. Reduction of Energetic Demands through Modification of Body Size and Routine Metabolic Rates in Extremophile Fish. Physiol Biochem Zool 2015; 88:371-83. [PMID: 26052634 DOI: 10.1086/681053] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Variation in energy availability or maintenance costs in extreme environments can exert selection for efficient energy use, and reductions in organismal energy demand can be achieved in two ways: reducing body mass or metabolic suppression. Whether long-term exposure to extreme environmental conditions drives adaptive shifts in body mass or metabolic rates remains an open question. We studied body size variation and variation in routine metabolic rates in locally adapted populations of extremophile fish (Poecilia mexicana) living in toxic, hydrogen sulfide-rich springs and caves. We quantified size distributions and routine metabolic rates in wild-caught individuals from four habitat types. Compared with ancestral populations in nonsulfidic surface habitats, extremophile populations were characterized by significant reductions in body size. Despite elevated metabolic rates in cave fish, the body size reduction precipitated in significantly reduced energy demands in all extremophile populations. Laboratory experiments on common garden-raised fish indicated that elevated routine metabolic rates in cave fish likely have a genetic basis. The results of this study indicate that adaptation to extreme environments directly impacts energy metabolism, with fish living in cave and sulfide spring environments expending less energy overall during routine metabolism.
Collapse
Affiliation(s)
- Courtney N Passow
- Department of Zoology, Oklahoma State University, 501 Life Sciences West, Stillwater, Oklahoma 74078; 2División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, Mexico
| | | | | | | | | |
Collapse
|
46
|
Culumber ZW, Schumer M, Monks S, Tobler M. Environmental heterogeneity generates opposite gene-by-environment interactions for two fitness-related traits within a population. Evolution 2015; 69:541-50. [PMID: 25496554 DOI: 10.1111/evo.12574] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [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: 07/03/2014] [Accepted: 10/27/2014] [Indexed: 12/17/2022]
Abstract
Theory predicts that environmental heterogeneity offers a potential solution to the maintenance of genetic variation within populations, but empirical evidence remains sparse. The live-bearing fish Xiphophorus variatus exhibits polymorphism at a single locus, with different alleles resulting in up to five distinct melanistic "tailspot" patterns within populations. We investigated the effects of heterogeneity in two ubiquitous environmental variables (temperature and food availability) on two fitness-related traits (upper thermal limits and body condition) in two different tailspot types (wild-type and upper cut crescent). We found gene-by-environment (G × E) interactions between tailspot type and food level affecting upper thermal limits (UTL), as well as between tailspot type and thermal environment affecting body condition. Exploring mechanistic bases underlying these G × E patterns, we found no differences between tailspot types in hsp70 gene expression despite significant overall increases in expression under both thermal and food stress. Similarly, there was no difference in routine metabolic rates between the tailspot types. The reversal of relative performance of the two tailspot types under different environmental conditions revealed a mechanism by which environmental heterogeneity can balance polymorphism within populations through selection on different fitness-related traits.
Collapse
Affiliation(s)
- Zachary W Culumber
- Centro de Investigaciones Cientificas de las Huastecas "Aguazarca", 392 Colonia Aguazarca, Calnali, Hidalgo, 43230, Mexico; Division of Biology, Kansas State University, Manhattan, Kansas, 66506.
| | | | | | | |
Collapse
|
47
|
Eifert C, Farnworth M, Schulz-Mirbach T, Riesch R, Bierbach D, Klaus S, Wurster A, Tobler M, Streit B, Indy JR, Arias-Rodriguez L, Plath M. Brain size variation in extremophile fish: local adaptation versus phenotypic plasticity. J Zool (1987) 2014. [DOI: 10.1111/jzo.12190] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- C. Eifert
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
| | - M. Farnworth
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
| | - T. Schulz-Mirbach
- Department Biology II; Ludwig-Maximilians-University; Planegg Germany
| | - R. Riesch
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
- School of Biological Sciences; Centre for Ecology, Evolution and Behaviour; Royal Holloway University of London; Egham Surrey UK
| | - D. Bierbach
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
- Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Berlin Germany
| | - S. Klaus
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
| | - A. Wurster
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
| | - M. Tobler
- Department of Zoology; Oklahoma State University; Stillwater OK USA
| | - B. Streit
- Department of Ecology and Evolution; J.W. Goethe University Frankfurt; Frankfurt am Main Germany
| | - J. R. Indy
- División Académica de Ciencias Biológicas; Universidad Juárez Autónoma de Tabasco (UJAT); Villahermosa Tabasco México
| | - L. Arias-Rodriguez
- División Académica de Ciencias Biológicas; Universidad Juárez Autónoma de Tabasco (UJAT); Villahermosa Tabasco México
| | - M. Plath
- College of Animal Science and Technology; Northwest A&F University; Yangling China
| |
Collapse
|
48
|
Culumber ZW, Bautista-Hernández CE, Monks S, Arias-Rodriguez L, Tobler M. Variation in Melanism and Female Preference in Proximate but Ecologically Distinct Environments. Ethology 2014. [DOI: 10.1111/eth.12282] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Zachary W. Culumber
- Centro de Investigaciones Cientificas de las Huastecas “Aguazarca”; Calnali Hidalgo Mexico
- Centro de Investigaciones Biologicas; Universidad Autónoma del Estado de Hidalgo; Pachuca Hidalgo Mexico
| | - Christian E. Bautista-Hernández
- Centro de Investigaciones Cientificas de las Huastecas “Aguazarca”; Calnali Hidalgo Mexico
- Centro de Investigaciones Biologicas; Universidad Autónoma del Estado de Hidalgo; Pachuca Hidalgo Mexico
| | - Scott Monks
- Centro de Investigaciones Biologicas; Universidad Autónoma del Estado de Hidalgo; Pachuca Hidalgo Mexico
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas; Universidad Juárez Autónoma de Tabasco (UJAT); Villahermosa Tabasco Mexico
| | - Michael Tobler
- Department of Zoology; Oklahoma State University; Stillwater OK USA
| |
Collapse
|
49
|
Sanchez JL, Boutwell BB, Hamontree ST, Garrett GP, Lewis RH, Ragan AN, Tobler M, Haynes RD. Reproductive characteristics of two Gambusiacongeners in west Texas. SOUTHWEST NAT 2014. [DOI: 10.1894/lw-05.1] [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: 11/20/2022]
|
50
|
|