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Ogbunugafor CB. The mutation effect reaction norm (mu-rn) highlights environmentally dependent mutation effects and epistatic interactions. Evolution 2022; 76:37-48. [PMID: 34989399 DOI: 10.1111/evo.14428] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/23/2021] [Indexed: 11/27/2022]
Abstract
Since the modern synthesis, the fitness effects of mutations and epistasis have been central yet provocative concepts in evolutionary and population genetics. Studies of how the interactions between parcels of genetic information can change as a function of environmental context have added a layer of complexity to these discussions. Here I introduce the "mutation effect reaction norm" (Mu-RN), a new instrument through which one can analyze the phenotypic consequences of mutations and interactions across environmental contexts. It embodies the fusion of measurements of genetic interactions with the reaction norm, a classic depiction of the performance of genotypes across environments. I demonstrate the utility of the Mu-RN through the signature of a "compensatory ratchet" mutation that undermines reverse evolution of antimicrobial resistance. More broadly, I argue that the mutation effect reaction norm may help us resolve the dynamism and unpredictability of evolution, with implications for theoretical biology, genetic modification technology, and public health. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- C Brandon Ogbunugafor
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
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2
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Martin LB, Hanson HE, Hauber ME, Ghalambor CK. Genes, Environments, and Phenotypic Plasticity in Immunology. Trends Immunol 2021; 42:198-208. [PMID: 33518415 DOI: 10.1016/j.it.2021.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 12/30/2022]
Abstract
For most of its history, immunology has sought to control environmental variation to establish genetic causality. As with all biological traits though, variation among individuals arises by three broad pathways: genetic (G), environmental (E), and the interactive between the two (GxE); and immunity is no different. Here, we review the value of applying the evolutionary frameworks of phenotypic plasticity and reaction norms to immunology. Because standardized laboratory environments are vastly different from the conditions under which populations evolved, we hypothesize that immunology might presently be missing important phenotypic variation and even focusing on dysregulated molecular and cellular processes. Modest adjustments to study designs could make model organism immunology more productive, reproducible, and reflective of human physiology.
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Affiliation(s)
- Lynn B Martin
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, USA.
| | - Haley E Hanson
- Center for Global Health and Infectious Disease Research, University of South Florida, Tampa, FL, USA
| | - Mark E Hauber
- Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois, Urbana-Champaign, IL, USA
| | - Cameron K Ghalambor
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Biology, Colorado State University, Fort Collins, CO, USA
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3
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Teigen LE, Sundberg CW, Kelly LJ, Hunter SK, Fitts RH. Ca 2+ dependency of limb muscle fiber contractile mechanics in young and older adults. Am J Physiol Cell Physiol 2020; 318:C1238-C1251. [PMID: 32348175 DOI: 10.1152/ajpcell.00575.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Age-induced declines in skeletal muscle contractile function have been attributed to multiple cellular factors, including lower peak force (Po), decreased Ca2+ sensitivity, and reduced shortening velocity (Vo). However, changes in these cellular properties with aging remain unresolved, especially in older women, and the effect of submaximal Ca2+ on contractile function is unknown. Thus, we compared contractile properties of muscle fibers from 19 young (24 ± 3 yr; 8 women) and 21 older adults (77 ± 7 yr; 7 women) under maximal and submaximal Ca2+ and assessed the abundance of three proteins thought to influence Ca2+ sensitivity. Fast fiber cross-sectional area was ~44% larger in young (6,479 ± 2,487 µm2) compared with older adults (4,503 ± 2,071 µm2, P < 0.001), which corresponded with a greater absolute Po (young = 1.12 ± 0.43 mN; old = 0.79 ± 0.33 mN, P < 0.001). There were no differences in fast fiber size-specific Po, indicating the age-related decline in force was explained by differences in fiber size. Except for fast fiber size and absolute Po, no age or sex differences were observed in Ca2+ sensitivity, rate of force development (ktr), or Vo in either slow or fast fibers. Submaximal Ca2+ depressed ktr and Vo, but the effects were not altered by age in either sex. Contrary to rodent studies, regulatory light chain (RLC) and myosin binding protein-C abundance and RLC phosphorylation were unaltered by age or sex. These data suggest the age-associated reductions in contractile function are primarily due to the atrophy of fast fibers and that caution is warranted when extending results from rodent studies to humans.
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Affiliation(s)
- Laura E Teigen
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Christopher W Sundberg
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
| | - Lauren J Kelly
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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4
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Lane RM, Smith A, Baumann T, Gleichmann M, Norris D, Bennett CF, Kordasiewicz H. Translating Antisense Technology into a Treatment for Huntington's Disease. Methods Mol Biol 2019; 1780:497-523. [PMID: 29856033 DOI: 10.1007/978-1-4939-7825-0_23] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Advances in molecular biology and genetics have been used to elucidate the fundamental genetic mechanisms underlying central nervous system (CNS) diseases, yet disease-modifying therapies are currently unavailable for most CNS conditions. Antisense oligonucleotides (ASOs) are synthetic single stranded chains of nucleic acids that bind to a specific sequence on ribonucleic acid (RNA) and regulate posttranscriptional gene expression. Decreased gene expression with ASOs might be able to reduce production of the disease-causing protein underlying dominantly inherited neurodegenerative disorders. Huntington's disease (HD), which is caused by a CAG repeat expansion in exon 1 of the huntingtin (HTT) gene and leads to the pathogenic expansion of a polyglutamine (PolyQ ) tract in the N terminus of the huntingtin protein (Htt), is a prime candidate for ASO therapy.State-of-the art translational science techniques can be applied to the development of an ASO targeting HTT RNA, allowing for a data-driven, stepwise progression through the drug development process. A deep and wide-ranging understanding of the basic, preclinical, clinical, and epidemiologic components of drug development will improve the likelihood of success. This includes characterizing the natural history of the disease, including evolution of biomarkers indexing the underlying pathology; using predictive preclinical models to assess the putative gain-of-function of mutant Htt protein and any loss-of-function of the wild-type protein; characterizing toxicokinetic and pharmacodynamic effects of ASOs in predictive animal models; developing sensitive and reliable biomarkers to monitor target engagement and effects on pathology that translate from animal models to patients with HD; establishing a drug delivery method that ensures reliable distribution to relevant CNS tissue; and designing clinical trials that move expeditiously from proof of concept to proof of efficacy. This review focuses on the translational science techniques that allow for efficient and informed development of an ASO for the treatment of HD.
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Affiliation(s)
| | - Anne Smith
- Ionis Pharmaceuticals, Carlsbad, CA, USA
| | | | | | - Dan Norris
- Ionis Pharmaceuticals, Carlsbad, CA, USA
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5
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Shaw DK, Tate AT, Schneider DS, Levashina EA, Kagan JC, Pal U, Fikrig E, Pedra JHF. Vector Immunity and Evolutionary Ecology: The Harmonious Dissonance. Trends Immunol 2018; 39:862-873. [PMID: 30301592 PMCID: PMC6218297 DOI: 10.1016/j.it.2018.09.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Revised: 09/11/2018] [Accepted: 09/11/2018] [Indexed: 12/19/2022]
Abstract
Recent scientific breakthroughs have significantly expanded our understanding of arthropod vector immunity. Insights in the laboratory have demonstrated how the immune system provides resistance to infection, and in what manner innate defenses protect against a microbial assault. Less understood, however, is the effect of biotic and abiotic factors on microbial-vector interactions and the impact of the immune system on arthropod populations in nature. Furthermore, the influence of genetic plasticity on the immune response against vector-borne pathogens remains mostly elusive. Herein, we discuss evolutionary forces that shape arthropod vector immunity. We focus on resistance, pathogenicity and tolerance to infection. We posit that novel scientific paradigms should emerge when molecular immunologists and evolutionary ecologists work together.
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Affiliation(s)
- Dana K Shaw
- Department of Veterinary Microbiology and Pathology, Washington State, Pullman, WA, USA.
| | - Ann T Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.
| | - David S Schneider
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, USA
| | - Elena A Levashina
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Jonathan C Kagan
- Division of Gastroenterology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park, MD, USA
| | - Erol Fikrig
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Joao H F Pedra
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
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6
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Leung JM, Budischak SA, Chung The H, Hansen C, Bowcutt R, Neill R, Shellman M, Loke P, Graham AL. Rapid environmental effects on gut nematode susceptibility in rewilded mice. PLoS Biol 2018. [PMID: 29518091 PMCID: PMC5843147 DOI: 10.1371/journal.pbio.2004108] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Genetic and environmental factors shape host susceptibility to infection, but how and how rapidly environmental variation might alter the susceptibility of mammalian genotypes remains unknown. Here, we investigate the impacts of seminatural environments upon the nematode susceptibility profiles of inbred C57BL/6 mice. We hypothesized that natural exposure to microbes might directly (e.g., via trophic interactions) or indirectly (e.g., via microbe-induced immune responses) alter the hatching, growth, and survival of nematodes in mice housed outdoors. We found that while C57BL/6 mice are resistant to high doses of nematode (Trichuris muris) eggs under clean laboratory conditions, exposure to outdoor environments significantly increased their susceptibility to infection, as evidenced by increased worm burdens and worm biomass. Indeed, mice kept outdoors harbored as many worms as signal transducer and activator of transcription 6 (STAT6) knockout mice, which are genetically deficient in the type 2 immune response essential for clearing nematodes. Using 16S ribosomal RNA sequencing of fecal samples, we discovered enhanced microbial diversity and specific bacterial taxa predictive of nematode burden in outdoor mice. We also observed decreased type 2 and increased type 1 immune responses in lamina propria and mesenteric lymph node (MLN) cells from infected mice residing outdoors. Importantly, in our experimental design, different groups of mice received nematode eggs either before or after moving outdoors. This contrasting timing of rewilding revealed that enhanced hatching of worms was not sufficient to explain the increased worm burdens; instead, microbial enhancement and type 1 immune facilitation of worm growth and survival, as hypothesized, were also necessary to explain our results. These findings demonstrate that environment can rapidly and significantly shape gut microbial communities and mucosal responses to nematode infections, leading to variation in parasite expulsion rates among genetically similar hosts. The environment in which an individual resides is likely to change how she or he responds to infection. However, most of our understanding about host responses to infection arises from experimental studies conducted under uniform environmental conditions in the laboratory. We wished to investigate whether findings in the laboratory translate into the wild. Therefore, in this study, we placed common strains of laboratory mice into large, outdoor enclosures to investigate how a more natural environment might impact their ability to combat intestinal worm infections. We found that while mice are able to clear worm infections in the laboratory, mice residing outdoors harbored higher worm burdens and larger worms than their laboratory cousins. The longer the mice lived outdoors, the greater the number and size of worms in their guts. We found that outdoor mice harbored more diverse gut microbes and even specific bacteria that may have impacted worm growth and survival inside the mice. Mice kept outdoors also produced decreased immune responses of the type essential for worm expulsion. Together, these results demonstrate that the external environment significantly alters how a host responds to worms and germs in her or his gut, thereby leading to variation in the outcome of infections.
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Affiliation(s)
- Jacqueline M. Leung
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- * E-mail: (JML); (ALG)
| | - Sarah A. Budischak
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Hao Chung The
- Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Vo Van Kiet, Ho Chi Minh City, Viet Nam
| | - Christina Hansen
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Rowann Bowcutt
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Rebecca Neill
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Mitchell Shellman
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - P’ng Loke
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Andrea L. Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- * E-mail: (JML); (ALG)
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7
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Brekke TD, Steele KA, Mulley JF. Inbred or Outbred? Genetic Diversity in Laboratory Rodent Colonies. G3 (BETHESDA, MD.) 2018; 8:679-686. [PMID: 29242387 PMCID: PMC5919727 DOI: 10.1534/g3.117.300495] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 12/12/2017] [Indexed: 12/15/2022]
Abstract
Nonmodel rodents are widely used as subjects for both basic and applied biological research, but the genetic diversity of the study individuals is rarely quantified. University-housed colonies tend to be small and subject to founder effects and genetic drift; so they may be highly inbred or show substantial genetic divergence from other colonies, even those derived from the same source. Disregard for the levels of genetic diversity in an animal colony may result in a failure to replicate results if a different colony is used to repeat an experiment, as different colonies may have fixed alternative variants. Here we use high throughput sequencing to demonstrate genetic divergence in three isolated colonies of Mongolian gerbil (Meriones unguiculatus) even though they were all established recently from the same source. We also show that genetic diversity in allegedly "outbred" colonies of nonmodel rodents (gerbils, hamsters, house mice, deer mice, and rats) varies considerably from nearly no segregating diversity to very high levels of polymorphism. We conclude that genetic divergence in isolated colonies may play an important role in the "replication crisis." In a more positive light, divergent rodent colonies represent an opportunity to leverage genetically distinct individuals in genetic crossing experiments. In sum, awareness of the genetic diversity of an animal colony is paramount as it allows researchers to properly replicate experiments and also to capitalize on other genetically distinct individuals to explore the genetic basis of a trait.
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Affiliation(s)
- Thomas D Brekke
- School of Biological Sciences, Bangor University, LL57 2DG, United Kingdom
| | - Katherine A Steele
- School of Environment, Natural Resources and Geography, Bangor University, LL57 2DG, United Kingdom
| | - John F Mulley
- School of Biological Sciences, Bangor University, LL57 2DG, United Kingdom
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8
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Coakley CM, Nestoros E, Little TJ. Testing hypotheses for maternal effects in Daphnia magna. J Evol Biol 2017; 31:211-216. [PMID: 29117456 PMCID: PMC6849578 DOI: 10.1111/jeb.13206] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 01/20/2023]
Abstract
Maternal effects are widely observed, but their adaptive nature remains difficult to describe and interpret. We investigated adaptive maternal effects in a clone of the crustacean Daphnia magna, experimentally varying both maternal age and maternal food and subsequently varying food available to offspring. We had two main predictions: that offspring in a food environment matched to their mothers should fare better than offspring in unmatched environments, and that offspring of older mothers would fare better in low food environments. We detected numerous maternal effects, for example offspring of poorly fed mothers were large, whereas offspring of older mothers were both large and showed an earlier age at first reproduction. However, these maternal effects did not clearly translate into the predicted differences in reproduction. Thus, our predictions about adaptive maternal effects in response to food variation were not met in this genotype of Daphnia magna.
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Affiliation(s)
- C M Coakley
- Institute of Global Change, School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - E Nestoros
- Institute of Global Change, School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - T J Little
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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9
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Clark J, Garbutt JS, McNally L, Little TJ. Disease spread in age structured populations with maternal age effects. Ecol Lett 2017; 20:445-451. [PMID: 28266095 PMCID: PMC6849612 DOI: 10.1111/ele.12745] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 10/24/2016] [Accepted: 01/09/2017] [Indexed: 12/23/2022]
Abstract
Fundamental ecological processes, such as extrinsic mortality, determine population age structure. This influences disease spread when individuals of different ages differ in susceptibility or when maternal age determines offspring susceptibility. We show that Daphnia magna offspring born to young mothers are more susceptible than those born to older mothers, and consider this alongside previous observations that susceptibility declines with age in this system. We used a susceptible‐infected compartmental model to investigate how age‐specific susceptibility and maternal age effects on offspring susceptibility interact with demographic factors affecting disease spread. Our results show a scenario where an increase in extrinsic mortality drives an increase in transmission potential. Thus, we identify a realistic context in which age effects and maternal effects produce conditions favouring disease transmission.
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Affiliation(s)
- Jessica Clark
- Institute of Evolutionary Biology, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland
| | - Jennie S Garbutt
- Institute of Evolutionary Biology, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland
| | - Luke McNally
- Institute of Evolutionary Biology, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland.,Centre for Immunity, Infection and Evolution, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland
| | - Tom J Little
- Institute of Evolutionary Biology, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland.,Centre for Immunity, Infection and Evolution, The University of Edinburgh, Ashworth Laboratories, Kings Buildings, Charlotte Auerbach Road, Edinburgh, EH9 3FL, Scotland
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10
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Garbutt JS, Little TJ. Bigger is better: changes in body size explain a maternal effect of food on offspring disease resistance. Ecol Evol 2017; 7:1403-1409. [PMID: 28261452 PMCID: PMC5330872 DOI: 10.1002/ece3.2709] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 11/16/2016] [Accepted: 12/17/2016] [Indexed: 11/08/2022] Open
Abstract
Maternal effects triggered by changes in the environment (e.g., nutrition or crowding) can influence the outcome of offspring–parasite interactions, with fitness consequences for the host and parasite. Outside of the classic example of antibody transfer in vertebrates, proximate mechanisms have been little studied, and thus, the adaptive significance of maternal effects on infection is not well resolved. We sought to determine why food‐stressed mothers give birth to offspring that show a low rate of infection when the crustacean Daphnia magna is exposed to an orally infective bacterial pathogen. These more‐resistant offspring are also larger at birth and feed at a lower rate. Thus, reduced disease resistance could result from slow‐feeding offspring ingesting fewer bacterial spores or because their larger size allows for greater immune investment. To distinguish between these theories, we performed an experiment in which we measured body size, feeding rate, and susceptibility, and were able to show that body size is the primary mechanism causing altered susceptibility: Larger Daphnia were less likely to become infected. Contrary to our predictions, there was also a trend that fast‐feeding Daphnia were less likely to become infected. Thus, our results explain how a maternal environmental effect can alter offspring disease resistance (though body size), and highlight the potential complexity of relationship between feeding rate and susceptibility in a host that encounters a parasite whilst feeding.
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Affiliation(s)
- Jennie S Garbutt
- Ashworth Laboratories Institute of Evolutionary Biology The University of Edinburgh Edinburgh UK
| | - Tom J Little
- Ashworth Laboratories Institute of Evolutionary Biology The University of Edinburgh Edinburgh UK
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11
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Sittig LJ, Carbonetto P, Engel KA, Krauss KS, Barrios-Camacho CM, Palmer AA. Genetic Background Limits Generalizability of Genotype-Phenotype Relationships. Neuron 2016; 91:1253-1259. [PMID: 27618673 PMCID: PMC5033712 DOI: 10.1016/j.neuron.2016.08.013] [Citation(s) in RCA: 162] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/11/2016] [Accepted: 08/08/2016] [Indexed: 01/16/2023]
Abstract
Genome-wide association studies (GWASs) have identified numerous loci that influence risk for psychiatric diseases. Genetically engineered mice are often used to characterize genes implicated by GWASs. These studies are based on the assumption that observed genotype-phenotype relationships will generalize to humans, implying that the results would at least generalize to other inbred mouse strains. Given current concerns about reproducibility, we sought to directly test this assumption. We produced F1 crosses between male C57BL/6J mice heterozygous for null alleles of Cacna1c and Tcf7l2 and wild-type females from 30 inbred laboratory strains. We found extremely strong interactions with genetic background that sometimes supported diametrically opposing conclusions. These results do not negate the invaluable contributions of mouse genetics to biomedical science, but they do show that genotype-phenotype relationships cannot be reliably inferred by studying a single genetic background, and thus constitute a major challenge to the status quo. VIDEO ABSTRACT.
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Affiliation(s)
- Laura J Sittig
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA; Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Peter Carbonetto
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA
| | - Kyle A Engel
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA
| | - Kathleen S Krauss
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA
| | - Camila M Barrios-Camacho
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA
| | - Abraham A Palmer
- Department of Human Genetics, University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA; Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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