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Choppin M, Feldmeyer B, Foitzik S. Histone acetylation regulates the expression of genes involved in worker reproduction in the ant Temnothorax rugatulus. BMC Genomics 2021; 22:871. [PMID: 34861814 PMCID: PMC8642982 DOI: 10.1186/s12864-021-08196-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/12/2021] [Indexed: 12/29/2022] Open
Abstract
Background In insect societies, queens monopolize reproduction while workers perform tasks such as brood care or foraging. Queen loss leads to ovary development and lifespan extension in workers of many ant species. However, the underlying molecular mechanisms of this phenotypic plasticity remain unclear. Recent studies highlight the importance of epigenetics in regulating plastic traits in social insects. Thus, we investigated the role of histone acetylation in regulating worker reproduction in the ant Temnothorax rugatulus. We removed queens from their colonies to induce worker fecundity, and either fed workers with chemical inhibitors of histone acetylation (C646), deacetylation (TSA), or the solvent (DMSO) as control. We monitored worker number for six weeks after which we assessed ovary development and sequenced fat body mRNA. Results Workers survived better in queenless colonies. They also developed their ovaries after queen removal in control colonies as expected, but not in colonies treated with the chemical inhibitors. Both inhibitors affected gene expression, although the inhibition of histone acetylation using C646 altered the expression of more genes with immunity, fecundity, and longevity functionalities. Interestingly, these C646-treated workers shared many upregulated genes with infertile workers from queenright colonies. We also identified one gene with antioxidant properties commonly downregulated in infertile workers from queenright colonies and both C646 and TSA-treated workers from queenless colonies. Conclusion Our results suggest that histone acetylation is involved in the molecular regulation of worker reproduction, and thus point to an important role of histone modifications in modulating phenotypic plasticity of life history traits in social insects. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08196-8.
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Affiliation(s)
- Marina Choppin
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany.
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Molecular Ecology, Senckenberg, Frankfurt, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
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Portera M, Mandrioli M. Who's afraid of epigenetics? Habits, instincts, and Charles Darwin's evolutionary theory. HISTORY AND PHILOSOPHY OF THE LIFE SCIENCES 2021; 43:20. [PMID: 33569656 PMCID: PMC7875938 DOI: 10.1007/s40656-021-00376-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
Our paper aims at bringing to the fore the crucial role that habits play in Charles Darwin's theory of evolution by means of natural selection. We have organized the paper in two steps: first, we analyse value and functions of the concept of habit in Darwin's early works, notably in his Notebooks, and compare these views to his mature understanding of the concept in the Origin of Species and later works; second, we discuss Darwin's ideas on habits in the light of today's theories of epigenetic inheritance, which describe the way in which the functioning and expression of genes is modified by the environment, and how these modifications are transmitted over generations. We argue that Darwin's lasting and multifaceted interest in the notion of habit, throughout his intellectual life, is both conceptually and methodologically relevant. From a conceptual point of view, intriguing similarities can be found between Darwin's (early) conception of habit and contemporary views on epigenetic inheritance. From a methodological point of view, we suggest that Darwin's plastic approach to habits, from his early writings up to the mature works, can provide today's evolutionary scientists with a viable methodological model to address the challenging task of extending and expanding evolutionary theory, with particular reference to the integration of epigenetic mechanisms into existing models of evolutionary change. Over his entire life Darwin has modified and reassessed his views on habits as many times as required by evidence: his work on this notion may represent the paradigm of a habit of good scientific research methodology.
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Affiliation(s)
- Mariagrazia Portera
- Dipartimento di Lettere e Filosofia, University of Florence, Firenze, Italy.
| | - Mauro Mandrioli
- Dipartimento di Scienze della Vita, University of Modena e Reggio Emilia, Modena, Italy
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Ma R, Rangel J, Grozinger CM. Honey bee (Apis mellifera) larval pheromones may regulate gene expression related to foraging task specialization. BMC Genomics 2019; 20:592. [PMID: 31324147 PMCID: PMC6642498 DOI: 10.1186/s12864-019-5923-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/21/2019] [Indexed: 12/22/2022] Open
Abstract
Background Foraging behavior in honey bees (Apis mellifera) is a complex phenotype that is regulated by physiological state and social signals. How these factors are integrated at the molecular level to modulate foraging behavior has not been well characterized. The transition of worker bees from nursing to foraging behaviors is mediated by large-scale changes in brain gene expression, which are influenced by pheromones produced by the queen and larvae. Larval pheromones can also stimulate foragers to leave the colony to collect pollen. However, the mechanisms underpinning this rapid behavioral plasticity in foragers that specialize in collecting pollen over nectar, and how larval pheromones impact these different behavioral states, remains to be determined. Here, we investigated the patterns of gene expression related to rapid behavioral plasticity and task allocation among honey bee foragers exposed to two larval pheromones, brood pheromone (BP) and (E)-beta-ocimene (EBO). We hypothesized that both pheromones would alter expression of genes in the brain related to foraging and would differentially impact brain gene expression depending on foraging specialization. Results Combining data reduction, clustering, and network analysis methods, we found that foraging preference (nectar vs. pollen) and pheromone exposure are each associated with specific brain gene expression profiles. Furthermore, pheromone exposure has a strong transcriptional effect on genes that are preferentially expressed in nectar foragers. Representation factor analysis between our study and previous landmark honey bee transcriptome studies revealed significant overlaps for both pheromone communication and foraging task specialization. Conclusions Our results suggest that, as social signals, pheromones alter expression patterns of foraging-related genes in the bee’s brain to increase pollen foraging at both long and short time scales. These results provide new insights into how social signals and task specialization are potentially integrated at the molecular level, and highlights the possible role that brain gene expression may play in honey bee behavioral plasticity across time scales. Electronic supplementary material The online version of this article (10.1186/s12864-019-5923-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rong Ma
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA.
| | - Juliana Rangel
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Center for Chemical Ecology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
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Cardoso-Júnior CAM, Guidugli-Lazzarini KR, Hartfelder K. DNA methylation affects the lifespan of honey bee (Apis mellifera L.) workers - Evidence for a regulatory module that involves vitellogenin expression but is independent of juvenile hormone function. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 92:21-29. [PMID: 29157677 DOI: 10.1016/j.ibmb.2017.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
The canonic regulatory module for lifespan of honey bee (Apis mellifera) workers involves a mutual repressor relationship between juvenile hormone (JH) and vitellogenin (Vg). Compared to vertebrates, however, little is known about a possible role of epigenetic factors. The full genomic repertoire of DNA methyltransferases (DNMTs) makes the honey bee an attractive emergent model for studying the role of epigenetics in the aging process of invertebrates, and especially so in social insects. We first quantified the transcript levels of the four DNMTs encoding genes in the head thorax and abdomens of workers of different age, showing that dnmt1a and dnmt3 expression is up-regulated in abdomens of old workers, whereas dnmt1b and dnmt2 are down-regulated in heads of old workers. Pharmacological genome demethylation by RG108 treatment caused an increase in worker lifespan. Next, we showed that the genomic DNA methylation status indirectly affects vitellogenin gene expression both in vitro and in vivo in young workers, and that this occurs independent of caloric restriction or JH levels, suggesting that a non-canonical circuitry may be acting in parallel with the JH/Vg module to regulate the adult life cycle of honey bee workers. Our data provide evidence that epigenetic factors play a role in regulatory networks associated with complex life history traits of a social insect.
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Affiliation(s)
- Carlos A M Cardoso-Júnior
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Karina R Guidugli-Lazzarini
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Klaus Hartfelder
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
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Frénoy A, Taddei F, Misevic D. Second-order cooperation: Cooperative offspring as a living public good arising from second-order selection on non-cooperative individuals. Evolution 2017; 71:1802-1814. [PMID: 28568812 DOI: 10.1111/evo.13279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 05/02/2017] [Indexed: 11/28/2022]
Abstract
Switching rate between cooperating and non-cooperating genotypes is a crucial social evolution factor, often neglected by game theory-inspired theoretical and experimental frameworks. We show that the evolution of alleles increasing the mutation or phenotypic switching rates toward cooperation is in itself a social dilemma. Although cooperative offspring are often unlikely to reproduce, due to high cost of cooperation, they can be seen both as a living public good and a part of the extended parental phenotype. The competition between individuals that generate cooperators and ones that do not is often more relevant than the competition between cooperators and non-cooperators. The dilemma of second-order cooperation we describe relates directly to eusociality, but can be also interpreted as a division of labor or a soma-germline distinction. The results of our simulations shine a new light on what Darwin had already termed a "special difficulty" of evolutionary theory and describe a novel type of cooperation dynamics.
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Affiliation(s)
- Antoine Frénoy
- Institute for Integrative Biology, ETH Zürich, Switzerland.,INSERM UMR 1001, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - François Taddei
- INSERM UMR 1001, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Dusan Misevic
- INSERM UMR 1001, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
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DUPRAS CHARLES. RAPPROCHEMENT DES PÔLES NATURE ET CULTURE PAR LA RECHERCHE EN ÉPIGÉNÉTIQUE : DISSECTION D’UN BOULEVERSEMENT ÉPISTÉMOLOGIQUE ATTENDU. ATELIERS DE L ETHIQUE-THE ETHICS FORUM 2017. [DOI: 10.7202/1051278ar] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Libbrecht R, Oxley PR, Keller L, Kronauer DJC. Robust DNA Methylation in the Clonal Raider Ant Brain. Curr Biol 2016; 26:391-5. [PMID: 26804553 PMCID: PMC5067136 DOI: 10.1016/j.cub.2015.12.040] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 10/30/2015] [Accepted: 12/09/2015] [Indexed: 12/20/2022]
Abstract
Social insects are promising model systems for epigenetics due to their immense morphological and behavioral plasticity. Reports that DNA methylation differs between the queen and worker castes in social insects [1-4] have implied a role for DNA methylation in regulating division of labor. To better understand the function of DNA methylation in social insects, we performed whole-genome bisulfite sequencing on brains of the clonal raider ant Cerapachys biroi, whose colonies alternate between reproductive (queen-like) and brood care (worker-like) phases [5]. Many cytosines were methylated in all replicates (on average 29.5% of the methylated cytosines in a given replicate), indicating that a large proportion of the C. biroi brain methylome is robust. Robust DNA methylation occurred preferentially in exonic CpGs of highly and stably expressed genes involved in core functions. Our analyses did not detect any differences in DNA methylation between the queen-like and worker-like phases, suggesting that DNA methylation is not associated with changes in reproduction and behavior in C. biroi. Finally, many cytosines were methylated in one sample only, due to either biological or experimental variation. By applying the statistical methods used in previous studies [1-4, 6] to our data, we show that such sample-specific DNA methylation may underlie the previous findings of queen- and worker-specific methylation. We argue that there is currently no evidence that genome-wide variation in DNA methylation is associated with the queen and worker castes in social insects, and we call for a more careful interpretation of the available data.
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Affiliation(s)
- Romain Libbrecht
- Laboratory of Social Evolution and Behavior, The Rockefeller University, New York, NY 10065, USA; Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Peter Robert Oxley
- Laboratory of Social Evolution and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
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Ruden DM, Cingolani PE, Sen A, Qu W, Wang L, Senut MC, Garfinkel MD, Sollars VE, Lu X. Epigenetics as an answer to Darwin's "special difficulty," Part 2: natural selection of metastable epialleles in honeybee castes. Front Genet 2015; 6:60. [PMID: 25759717 PMCID: PMC4338822 DOI: 10.3389/fgene.2015.00060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 02/08/2015] [Indexed: 11/15/2022] Open
Abstract
In a recent perspective in this journal, Herb (2014) discussed how epigenetics is a possible mechanism to circumvent Charles Darwin's "special difficulty" in using natural selection to explain the existence of the sterile-fertile dimorphism in eusocial insects. Darwin's classic book "On the Origin of Species by Means of Natural Selection" explains how natural selection of the fittest individuals in a population can allow a species to adapt to a novel or changing environment. However, in bees and other eusocial insects, such as ants and termites, there exist two or more castes of genetically similar females, from fertile queens to multiple sub-castes of sterile workers, with vastly different phenotypes, lifespans, and behaviors. This necessitates the selection of groups (or kin) rather than individuals in the evolution of honeybee hives, but group and kin selection theories of evolution are controversial and mechanistically uncertain. Also, group selection would seem to be prohibitively inefficient because the effective population size of a colony is reduced from thousands to a single breeding queen. In this follow-up perspective, we elaborate on possible mechanisms for how a combination of both epigenetics, specifically, the selection of metastable epialleles, and genetics, the selection of mutations generated by the selected metastable epialleles, allows for a combined means for selection amongst the fertile members of a species to increase colony fitness. This "intra-caste evolution" hypothesis is a variation of the epigenetic directed genetic error hypothesis, which proposes that selected metastable epialleles increase genetic variability by directing mutations specifically to the epialleles. Natural selection of random metastable epialleles followed by a second round of natural selection of random mutations generated by the metastable epialleles would allow a way around the small effective population size of eusocial insects.
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Affiliation(s)
- Douglas M. Ruden
- Department of Obstetrics and Gynecology, C. S. Mott Center for Human Growth and Development and Center for Urban Responses to Environmental Stressors, Institute of Environmental Health Sciences, Wayne State UniversityDetroit, MI, USA
| | - Pablo E. Cingolani
- School of Computer Science and Genome Quebec Innovation Centre, McGill UniversityMontreal, QC, Canada
| | - Arko Sen
- Department of Pharmacology, Wayne State UniversityDetroit, MI, USA
| | - Wen Qu
- Department of Pharmacology, Wayne State UniversityDetroit, MI, USA
| | - Luan Wang
- Institute of Environmental Health Sciences, Wayne State UniversityDetroit, MI, USA
| | - Marie-Claude Senut
- Institute of Environmental Health Sciences, Wayne State UniversityDetroit, MI, USA
| | - Mark D. Garfinkel
- Department of Biological Sciences, University of Alabama in HuntsvilleHuntsville, AL, USA
| | - Vincent E. Sollars
- Department of Biochemistry and Microbiology, Joan C. Edwards School of Medicine, Marshall UniversityHuntington, WV, USA
| | - Xiangyi Lu
- Institute of Environmental Health Sciences, Wayne State UniversityDetroit, MI, USA
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