1
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Geens B, Goossens S, Li J, Van de Peer Y, Vanden Broeck J. Untangling the gordian knot: The intertwining interactions between developmental hormone signaling and epigenetic mechanisms in insects. Mol Cell Endocrinol 2024; 585:112178. [PMID: 38342134 DOI: 10.1016/j.mce.2024.112178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/30/2024] [Accepted: 02/04/2024] [Indexed: 02/13/2024]
Abstract
Hormones control developmental and physiological processes, often by regulating the expression of multiple genes simultaneously or sequentially. Crosstalk between hormones and epigenetics is pivotal to dynamically coordinate this process. Hormonal signals can guide the addition and removal of epigenetic marks, steering gene expression. Conversely, DNA methylation, histone modifications and non-coding RNAs can modulate regional chromatin structure and accessibility and regulate the expression of numerous (hormone-related) genes. Here, we provide a review of the interplay between the classical insect hormones, ecdysteroids and juvenile hormones, and epigenetics. We summarize the mode-of-action and roles of these hormones in post-embryonic development, and provide a general overview of epigenetic mechanisms. We then highlight recent advances on the interactions between these hormonal pathways and epigenetics, and their involvement in development. Furthermore, we give an overview of several 'omics techniques employed in the field. Finally, we discuss which questions remain unanswered and possible avenues for future research.
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Affiliation(s)
- Bart Geens
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59 box 2465, B-3000 Leuven, Belgium.
| | - Stijn Goossens
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59 box 2465, B-3000 Leuven, Belgium.
| | - Jia Li
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; VIB Center for Plant Systems Biology, VIB, Ghent, Belgium.
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; VIB Center for Plant Systems Biology, VIB, Ghent, Belgium.
| | - Jozef Vanden Broeck
- Molecular Developmental Physiology and Signal Transduction, KU Leuven, Naamsestraat 59 box 2465, B-3000 Leuven, Belgium.
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2
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Mikhailova AA, Rinke S, Harrison MC. Genomic signatures of eusocial evolution in insects. CURRENT OPINION IN INSECT SCIENCE 2024; 61:101136. [PMID: 37922983 DOI: 10.1016/j.cois.2023.101136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/27/2023] [Accepted: 10/28/2023] [Indexed: 11/07/2023]
Abstract
The genomes of eusocial insects allow the production and regulation of highly distinct phenotypes, largely independent of genotype. Although rare, eusociality has evolved convergently in at least three insect orders (Hymenoptera, Blattodea and Coleoptera). Despite such disparate origins, eusocial phenotypes show remarkable similarity, exhibiting long-lived reproductives and short-lived sterile workers and soldiers. In this article, we review current knowledge on genomic signatures of eusocial evolution. We confirm that especially an increased regulatory complexity and the adaptive evolution of chemical communication are common to several origins of eusociality. Furthermore, colony life itself can shape genomes of divergent taxa in a similar manner. Future research should be geared towards generating more high-quality genomic resources, especially in hitherto understudied clades, such as ambrosia beetles and termites. The application of more sophisticated tools such as machine learning techniques may allow the detection of more subtle convergent genomic footprints of eusociality.
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Affiliation(s)
- Alina A Mikhailova
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasße 1, 48149 Münster, Germany
| | - Sarah Rinke
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasße 1, 48149 Münster, Germany
| | - Mark C Harrison
- Institute for Evolution and Biodiversity, University of Münster, Hüfferstrasße 1, 48149 Münster, Germany.
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3
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Taylor BA, Taylor D, Bodrug‐Schepers A, Câmara Ferreira F, Stralis‐Pavese N, Himmelbauer H, Guigó R, Reuter M, Sumner S. Molecular signatures of alternative reproductive strategies in a facultatively social hover wasp. Mol Ecol 2024; 33:e17217. [PMID: 38014715 PMCID: PMC10953455 DOI: 10.1111/mec.17217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 11/09/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023]
Abstract
Social insect reproductives and non-reproductives represent ideal models with which to understand the expression and regulation of alternative phenotypes. Most research in this area has focused on the developmental regulation of reproductive phenotypes in obligately social taxa such as honey bees, while relatively few studies have addressed the molecular correlates of reproductive differentiation in species in which the division of reproductive labour is established only in plastic dominance hierarchies. To address this knowledge gap, we generate the first genome for any stenogastrine wasp and analyse brain transcriptomic data for non-reproductives and reproductives of the facultatively social species Liostenogaster flavolineata, a representative of one of the simplest forms of social living. By experimentally manipulating the reproductive 'queues' exhibited by social colonies of this species, we show that reproductive division of labour in this species is associated with transcriptomic signatures that are more subtle and variable than those observed in social taxa in which colony living has become obligate; that variation in gene expression among non-reproductives reflects their investment into foraging effort more than their social rank; and that genes associated with reproductive division of labour overlap to some extent with those underlying division of labour in the separate polistine origin of wasp sociality but only explain a small portion of overall variation in this trait. These results indicate that broad patterns of within-colony transcriptomic differentiation in this species are similar to those in Polistinae but offer little support for the existence of a strongly conserved 'toolkit' for sociality.
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Affiliation(s)
- Benjamin A. Taylor
- Centre for Biodiversity & Environment ResearchUniversity College LondonLondonUK
- Department of Genetics, Evolution & EnvironmentUniversity College LondonLondonUK
| | - Daisy Taylor
- School of Biological SciencesUniversity of BristolBristolUK
| | | | | | - Nancy Stralis‐Pavese
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Heinz Himmelbauer
- Department of BiotechnologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Roderic Guigó
- Centre for Genomic RegulationBarcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu FabraBarcelonaSpain
| | - Max Reuter
- Department of Genetics, Evolution & EnvironmentUniversity College LondonLondonUK
- Centre for Life's Origins and EvolutionUniversity College LondonLondonUK
| | - Seirian Sumner
- Centre for Biodiversity & Environment ResearchUniversity College LondonLondonUK
- Department of Genetics, Evolution & EnvironmentUniversity College LondonLondonUK
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4
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Arsenault SV, Riba-Grognuz O, Shoemaker D, Hunt BG, Keller L. Direct and indirect genetic effects of a social supergene. Mol Ecol 2023; 32:1087-1097. [PMID: 36541826 DOI: 10.1111/mec.16830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
Indirect genetic effects describe phenotypic variation that results from differences in the genotypic composition of social partners. Such effects represent heritable sources of environmental variation in eusocial organisms because individuals are typically reared by their siblings. In the fire ant Solenopsis invicta, a social supergene exhibits striking indirect genetic effects on worker regulation of colony queen number, such that the genotypic composition of workers at the supergene determines whether colonies contain a single or multiple queens. We assessed the direct and indirect genetic effects of this supergene on gene expression in brains and abdominal tissues from laboratory-reared workers and compared these with previously published data from field-collected prereproductive queens. We found that direct genetic effects caused larger gene expression changes and were more consistent across tissue types and castes than indirect genetic effects. Indirect genetic effects influenced the expression of many loci but were generally restricted to the abdominal tissues. Further, indirect genetic effects were only detected when the genotypic composition of social partners differed throughout the development and adult life of focal workers, and were often only significant with relatively lenient statistical cutoffs. Our study provides insight into direct and indirect genetic effects of a social supergene on gene regulatory dynamics across tissues and castes in a complex society.
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Affiliation(s)
| | - Oksana Riba-Grognuz
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - DeWayne Shoemaker
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| | - Brendan G Hunt
- Department of Entomology, University of Georgia, Athens, Georgia, USA
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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5
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Both age and social environment shape the phenotype of ant workers. Sci Rep 2023; 13:186. [PMID: 36604491 PMCID: PMC9814961 DOI: 10.1038/s41598-022-26515-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 12/15/2022] [Indexed: 01/06/2023] Open
Abstract
Position within the social group has consequences on individual lifespans in diverse taxa. This is especially obvious in eusocial insects, where workers differ in both the tasks they perform and their aging rates. However, in eusocial wasps, bees and ants, the performed task usually depends strongly on age. As such, untangling the effects of social role and age on worker physiology is a key step towards understanding the coevolution of sociality and aging. We performed an experimental protocol that allowed a separate analysis of these two factors using four groups of black garden ant (Lasius niger) workers: young foragers, old foragers, young nest workers, and old nest workers. We highlighted age-related differences in the proteome and metabolome of workers that were primarily related to worker subcaste and only secondarily to age. The relative abundance of proteins and metabolites suggests an improved xenobiotic detoxification, and a fuel metabolism based more on lipid use than carbohydrate use in young ants, regardless of their social role. Regardless of age, proteins related to the digestive function were more abundant in nest workers than in foragers. Old foragers were mostly characterized by weak abundances of molecules with an antibiotic activity or involved in chemical communication. Finally, our results suggest that even in tiny insects, extended lifespan may require to mitigate cancer risks. This is consistent with results found in eusocial rodents and thus opens up the discussion of shared mechanisms among distant taxa and the influence of sociality on life history traits such as longevity.
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Quque M, Villette C, Criscuolo F, Sueur C, Bertile F, Heintz D. Eusociality is linked to caste-specific differences in metabolism, immune system, and somatic maintenance-related processes in an ant species. Cell Mol Life Sci 2021; 79:29. [PMID: 34971425 PMCID: PMC11073003 DOI: 10.1007/s00018-021-04024-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/08/2021] [Accepted: 11/05/2021] [Indexed: 01/08/2023]
Abstract
The social organization of many primate, bird and rodent species and the role of individuals within that organization are associated with specific individual physiological traits. However, this association is perhaps most pronounced in eusocial insects (e.g., termites, ants). In such species, genetically close individuals show significant differences in behavior, physiology, and life expectancy. Studies addressing the metabolic changes according to the social role are still lacking. We aimed at understanding how sociality could influence essential molecular processes in a eusocial insect, the black garden ant (Lasius niger) where queens can live up to ten times longer than workers. Using mass spectrometry-based analysis, we explored the whole metabolome of queens, nest-workers and foraging workers. A former proteomics study done in the same species allowed us to compare the findings of both approaches. Confirming the former results at the proteome level, we showed that queens had fewer metabolites related to immunity. Contrary to our predictions, we did not find any metabolite linked to reproduction in queens. Among the workers, foragers had a metabolic signature reflecting a more stressful environment and a more highly stimulated immune system. We also found that nest-workers had more digestion-related metabolites. Hence, we showed that specific metabolic signatures match specific social roles. Besides, we identified metabolites differently expressed among behavioral castes and involved in nutrient sensing and longevity pathways (e.g., sirtuins, FOXO). The links between such molecular pathways and aging being found in an increasing number of taxa, our results confirm and strengthen their potential universality.
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Affiliation(s)
- Martin Quque
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, F-67000, Strasbourg, France.
| | - Claire Villette
- Plant Imaging and Mass Spectrometry (PIMS), Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, F-67000, Strasbourg, France
| | - François Criscuolo
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, F-67000, Strasbourg, France
| | - Cédric Sueur
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, F-67000, Strasbourg, France
- Institut Universitaire de France, 75005, Paris, France
| | - Fabrice Bertile
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, F-67000, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI, FR2048, Strasbourg, France
| | - Dimitri Heintz
- Plant Imaging and Mass Spectrometry (PIMS), Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, F-67000, Strasbourg, France
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7
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Harrison MC, Niño LMJ, Rodrigues MA, Ryll J, Flatt T, Oettler J, Bornberg-Bauer E. Gene Coexpression Network Reveals Highly Conserved, Well-Regulated Anti-Ageing Mechanisms in Old Ant Queens. Genome Biol Evol 2021; 13:6263858. [PMID: 33944936 PMCID: PMC8214412 DOI: 10.1093/gbe/evab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2021] [Indexed: 12/11/2022] Open
Abstract
Evolutionary theories of ageing predict a reduction in selection efficiency with age, a so-called “selection shadow,” due to extrinsic mortality decreasing effective population size with age. Classic symptoms of ageing include a deterioration in transcriptional regulation and protein homeostasis. Understanding how ant queens defy the trade-off between fecundity and lifespan remains a major challenge for the evolutionary theory of ageing. It has often been discussed that the low extrinsic mortality of ant queens, that are generally well protected within the nest by workers and soldiers, should reduce the selection shadow acting on old queens. We tested this by comparing strength of selection acting on genes upregulated in young and old queens of the ant, Cardiocondyla obscurior. In support of a reduced selection shadow, we find old-biased genes to be under strong purifying selection. We also analyzed a gene coexpression network (GCN) with the aim to detect signs of ageing in the form of deteriorating regulation and proteostasis. We find no evidence for ageing. In fact, we detect higher connectivity in old queens indicating increased transcriptional regulation with age. Within the GCN, we discover five highly correlated modules that are upregulated with age. These old-biased modules regulate several antiageing mechanisms such as maintenance of proteostasis, transcriptional regulation, and stress response. We observe stronger purifying selection on central hub genes of these old-biased modules compared with young-biased modules. These results indicate a lack of transcriptional ageing in old C. obscurior queens, possibly facilitated by strong selection at old age and well-regulated antiageing mechanisms.
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Affiliation(s)
- Mark C Harrison
- Institute for Evolution and Biodiversity, University of Münster, Germany
| | | | | | - Judith Ryll
- Institute for Evolution and Biodiversity, University of Münster, Germany
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Switzerland
| | - Jan Oettler
- Institut für Zoologie/Evolutionsbiologie, University of Regensburg, Germany
| | - Erich Bornberg-Bauer
- Department of Biology, University of Fribourg, Switzerland.,Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
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8
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Miyazaki S, Shimoji H, Suzuki R, Chinushi I, Takayanagi H, Yaguchi H, Miura T, Maekawa K. Expressions of conventional vitellogenin and vitellogenin-like A in worker brains are associated with a nursing task in a ponerine ant. INSECT MOLECULAR BIOLOGY 2021; 30:113-121. [PMID: 33150669 DOI: 10.1111/imb.12682] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
In eusocial insect colonies, non-reproductive workers often perform different tasks. Tasks of an individual worker are shifted depending on various factors, e.g., age and colony demography. Although a vitellogenin (Vg) gene play regulatory roles in both reproductive and non-reproductive division of labours in a honeybee, it has been shown that the insect Vg underwent multiple gene duplications and sub-functionalisation, especially in apical ant lineages. The regulatory roles of duplicated Vgs were suggested to change evolutionarily among ants, whereas such roles in phylogenetically basal ants remain unclear. Here, we examined the expression patterns of conventional Vg (CVg), Vg-like A, Vg-like B and Vg-like C, as well as Vg receptor, during the task shift in an age-dependent manner and under experimental manipulation of colony demography in a primitive ant Diacamma sp. Expressions of CVg and Vg-like A in a brain were associated with a nursing task. It is suggested that associations of brain expressions of these Vgs with worker tasks were acquired in the basal ant lineage, and that such Vg functions could have sub-functionalised in the derived ant lineage.
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Affiliation(s)
- S Miyazaki
- Graduate School of Agriculture, Tamagawa University, Tokyo, Japan
| | - H Shimoji
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- School of Science and Technology, Kwansei Gakuin University, Sanda, Japan
| | - R Suzuki
- Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - I Chinushi
- Graduate School of Agriculture, Tamagawa University, Tokyo, Japan
| | - H Takayanagi
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
| | - H Yaguchi
- School of Science and Technology, Kwansei Gakuin University, Sanda, Japan
- Graduate School of Science and Engineering, University of Toyama, Toyama, Japan
| | - T Miura
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Japan
| | - K Maekawa
- Faculty of Science, Academic Assembly, University of Toyama, Toyama, Japan
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9
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Perez R, Aron S. Adaptations to thermal stress in social insects: recent advances and future directions. Biol Rev Camb Philos Soc 2020; 95:1535-1553. [PMID: 33021060 DOI: 10.1111/brv.12628] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/20/2023]
Abstract
Thermal stress is a major driver of population declines and extinctions. Shifts in thermal regimes create new environmental conditions, leading to trait adaptation, population migration, and/or species extinction. Extensive research has examined thermal adaptations in terrestrial arthropods. However, little is known about social insects, despite their major role in ecosystems. It is only within the last few years that the adaptations of social insects to thermal stress have received attention. Herein, we discuss what is currently known about thermal tolerance and thermal adaptation in social insects - namely ants, termites, social bees, and social wasps. We describe the behavioural, morphological, physiological, and molecular adaptations that social insects have evolved to cope with thermal stress. We examine individual and collective responses to both temporary and persistent changes in thermal conditions and explore the extent to which individuals can exploit genetic variability to acclimatise. Finally, we consider the costs and benefits of sociality in the face of thermal stress, and we propose some future research directions that should advance our knowledge of individual and collective thermal adaptations in social insects.
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Affiliation(s)
- Rémy Perez
- Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium
| | - Serge Aron
- Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium
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10
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Warner MR, Qiu L, Holmes MJ, Mikheyev AS, Linksvayer TA. Convergent eusocial evolution is based on a shared reproductive groundplan plus lineage-specific plastic genes. Nat Commun 2019; 10:2651. [PMID: 31201311 PMCID: PMC6570765 DOI: 10.1038/s41467-019-10546-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/14/2019] [Indexed: 12/31/2022] Open
Abstract
Eusociality has convergently evolved multiple times, but the genomic basis of caste-based division of labor and degree to which independent origins of eusociality have utilized common genes remain largely unknown. Here we characterize caste-specific transcriptomic profiles across development and adult body segments from pharaoh ants (Monomorium pharaonis) and honey bees (Apis mellifera), representing two independent origins of eusociality. We identify a substantial shared core of genes upregulated in the abdomens of queen ants and honey bees that also tends to be upregulated in mated female flies, suggesting that these genes are part of a conserved insect reproductive groundplan. Outside of this shared groundplan, few genes are differentially expressed in common. Instead, the majority of the thousands of caste-associated genes are plastically expressed, rapidly evolving, and relatively evolutionarily young. These results emphasize that the recruitment of both highly conserved and lineage-specific genes underlie the convergent evolution of novel traits such as eusociality. Eusocial caste systems have evolved independently multiple times. Here, Warner et al. investigate the amount of shared vs. lineage-specific genes involved in the evolution of caste in pharaoh ants and honey bees by comparing transcriptomes across tissues, developmental stages, and castes.
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Affiliation(s)
| | - Lijun Qiu
- Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Michael J Holmes
- Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan.,School of Life and Environmental Science, University of Sydney, Sydney, 2006, Australia
| | - Alexander S Mikheyev
- Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan.,Research School of Biology, Australian National University, Canberra, 0200, Australia
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11
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Long-lived Temnothorax ant queens switch from investment in immunity to antioxidant production with age. Sci Rep 2019; 9:7270. [PMID: 31086243 PMCID: PMC6514213 DOI: 10.1038/s41598-019-43796-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/15/2019] [Indexed: 01/09/2023] Open
Abstract
Senescence is manifested by an increase in molecular damage and a deterioration of biological functions with age. In most organisms, body maintenance is traded-off with reproduction. This negative relationship between longevity and fecundity is also evident on the molecular level. Exempt from this negative trait association, social insect queens are both extremely long-lived and highly fecund. Here, we study changes in gene expression with age and fecundity in ant queens to understand the molecular basis of their long lifespan. We analyse tissue-specific gene expression in young founding queens and old fecund queens of the ant Temnothorax rugatulus. More genes altered their expression with age in the fat body than in the brain. Despite strong differences in ovary development, few fecundity genes were differentially expressed. Young founding queens invested in immunity (i.e. activation of Toll signalling pathway) and resistance against environmental and physiological stress (i.e. down-regulation of TOR pathway). Conversely, established older queens invested into anti-aging mechanisms through an overproduction of antioxidants (i.e. upregulation of catalase, superoxide dismutase). Finally, we identified candidate genes and pathways, potentially involved in the association between fertility and longevity in social insects and its proximate basis.
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12
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Qiu B, Larsen RS, Chang NC, Wang J, Boomsma JJ, Zhang G. Towards reconstructing the ancestral brain gene-network regulating caste differentiation in ants. Nat Ecol Evol 2018; 2:1782-1791. [PMID: 30349091 PMCID: PMC6217981 DOI: 10.1038/s41559-018-0689-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/06/2018] [Indexed: 12/15/2022]
Abstract
Specialized queens and life-time unmated workers evolved once in the common ancestor of all ants, but whether caste development across ants continues to be at least partly regulated by a single core set of genes remains obscure. We analysed brain transcriptomes from five ant species (three subfamilies) and reconstructed the origins of genes with caste-biased expression. Ancient genes predating the Neoptera were more likely to regulate gyne (virgin queen) phenotypes, while caste differentiation roles of younger, ant-lineage-specific genes varied. Transcriptome profiling showed that the ancestral network for caste-specific gene-regulation has been maintained, but that signatures of common ancestry are obscured by later modifications. Adjusting for such differences, we identified a core gene-set that: 1. consistently displayed similar directions and degrees of caste-differentiated expression, and 2. have mostly not been reported as being involved in caste differentiation. These core regulatory genes exist in the genomes of ant species that secondarily lost the queen caste, but expression differences for reproductive and sterile workers are minor and similar to social paper wasps that lack differentiated castes. Many caste-biased ant genes have caste-differentiated expression in honeybees, but directions of caste bias were uncorrelated, as expected when permanent castes evolved independently in both lineages.
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Affiliation(s)
- Bitao Qiu
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Stenbak Larsen
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ni-Chen Chang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - John Wang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Guojie Zhang
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark. .,China National GeneBank, BGI-Shenzhen, Shenzhen, China. .,State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
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13
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Lucas ER, Keller L. Elevated expression of ageing and immunity genes in queens of the black garden ant. Exp Gerontol 2018; 108:92-98. [PMID: 29625209 DOI: 10.1016/j.exger.2018.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
Studies in model organisms have identified a variety of genes whose expression can be experimentally modulated to produce changes in longevity, but whether these genes are the same as those involved in natural variation in lifespan remains unclear. Social insects boast some of the largest lifespan differences known between plastic phenotypes, with queen and worker lifespans differing by an order of magnitude despite no systematic nucleotide sequence differences between them. The contrasting lifespans of queens and workers are thus the result of differences in gene expression. We used RNA sequencing of brains and legs in 1-day-old and 2-month-old individuals of the ant Lasius niger to determine whether genes with queen-biased expression are enriched for genes linked to ageing in model organisms. Because the great longevity of queens may require investment into immune processes, we also investigated whether queen-biased genes are enriched for genes with known roles in immunity. Queen-biased genes in legs were enriched for ageing genes and for genes associated with increasing rather than decreasing lifespan. Queen-biased genes in legs were also enriched for immune genes, but only in 1-day-old individuals, perhaps linked to the changing roles of workers with age. Intriguingly, the single most differentially expressed gene between 1-day-old queen and worker brains was an extra-cellular form of CuZn Superoxide Dismutase (SOD3), raising the possibility of an important role of anti-oxidant genes in modulating lifespan.
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Affiliation(s)
- Eric R Lucas
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
| | - Laurent Keller
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
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Favreau E, Martínez-Ruiz C, Rodrigues Santiago L, Hammond RL, Wurm Y. Genes and genomic processes underpinning the social lives of ants. CURRENT OPINION IN INSECT SCIENCE 2018; 25:83-90. [PMID: 29602366 DOI: 10.1016/j.cois.2017.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 12/05/2017] [Indexed: 05/06/2023]
Abstract
The >15000 ant species are all highly social and show great variation in colony organization, complexity and behavior. The mechanisms by which such sociality evolved, as well as those underpinning the elaboration of ant societies since their ∼140 million year old common ancestor, have long been pondered. Here, we review recent insights generated using various genomic approaches. This includes understanding the molecular mechanisms underlying caste differentiation and the diversity of social structures, studying the impact of eusociality on genomic evolutionary rates, and investigating gene expression changes associated with differences in lifespan between castes. Furthermore, functional studies involving RNAi and CRISPR have recently been successfully applied to ants, opening the door to exciting research that promises to revolutionize the understanding of the evolution and diversification of social living.
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Affiliation(s)
- Emeline Favreau
- Organismal Biology Department, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Carlos Martínez-Ruiz
- Organismal Biology Department, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Leandro Rodrigues Santiago
- Organismal Biology Department, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Robert L Hammond
- Department of Genetics and Genome Biology, University of Leicester, Leicester LE1 7RH, United Kingdom.
| | - Yannick Wurm
- Organismal Biology Department, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
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Abstract
The study of insect social behavior has offered tremendous insight into the molecular mechanisms mediating behavioral and phenotypic plasticity. Genomic applications to the study of eusocial insect species, in particular, have led to several hypotheses for the processes underlying the molecular evolution of behavior. Advances in understanding the genetic control of social organization have also been made, suggesting an important role for supergenes in the evolution of divergent behavioral phenotypes. Intensive study of social phenotypes across species has revealed that behavior and caste are controlled by an interaction between genetic and environmentally mediated effects and, further, that gene expression and regulation mediate plastic responses to environmental signals. However, several key methodological flaws that are hindering progress in the study of insect social behavior remain. After reviewing the current state of knowledge, we outline ongoing challenges in experimental design that remain to be overcome in order to advance the field.
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Affiliation(s)
- Chelsea A Weitekamp
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland; ,
| | - Romain Libbrecht
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, 55128 Mainz, Germany;
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland; ,
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