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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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2
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Hasenjager MJ, Hoppitt W, Cunningham-Eurich I, Franks VR, Leadbeater E. Coupled information networks drive honeybee (Apis mellifera) collective foraging. J Anim Ecol 2024; 93:71-82. [PMID: 38009606 DOI: 10.1111/1365-2656.14029] [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: 02/08/2023] [Accepted: 10/13/2023] [Indexed: 11/29/2023]
Abstract
Collective behaviour by eusocial insect colonies is typically achieved through multiple communication networks that produce complex behaviour at the group level but often appear to provide redundant or even competing information. A classic example occurs in honeybee (Apis mellifera) colonies, where both the dance communication system and robust scent-based mechanisms contribute to the allocation of a colony's workforce by regulating the flow of experienced foragers among known food sources. Here we analysed social connectivity patterns during the reactivation of experienced foragers to familiar feeding sites to show that these social information pathways are not simply multiple means to achieve the same end but intersect to play complementary roles in guiding forager behaviour. Using artificial feeding stations, we mimicked a natural scenario in which two forager groups were simultaneously collecting from distinct patches containing different flowering species. We then observed the reactivation of these groups at their familiar feeding sites after interrupting their foraging. Social network analysis revealed that temporarily unemployed individuals interacted more often and for longer with foragers that advertised a familiar versus unfamiliar foraging site. Due to such resource-based assortative mixing, network-based diffusion analysis estimated that reactivation events primarily resulted from interactions among bees that had been trained to the same feeding station and less so from different-feeder interactions. Both scent- and dance-based interactions strongly contributed to reactivation decisions. However, each bout of dance-following had an especially strong effect on a follower's likelihood of reactivation, particularly when dances indicated locations familiar to followers. Our findings illustrate how honeybee foragers can alter their social connectivity in ways that are likely to enhance collective outcomes by enabling foragers to rapidly access up-to-date information about familiar foraging sites. In addition, our results highlight how reliance on multiple communication mechanisms enables social insect workers to utilise flexible information-use strategies that are robust to variation in the availability of social information.
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Affiliation(s)
- Matthew J Hasenjager
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, USA
- National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, Tennessee, USA
- Department of Biological Sciences, Royal Holloway, University of London, Egham, UK
| | - William Hoppitt
- Department of Biological Sciences, Royal Holloway, University of London, Egham, UK
| | - Iona Cunningham-Eurich
- Department of Biological Sciences, Royal Holloway, University of London, Egham, UK
- Natural History Museum, London, UK
- Department of Genetics, Evolution, and Environment, University College London, London, UK
| | - Victoria R Franks
- Department of Biological Sciences, Royal Holloway, University of London, Egham, UK
- Department of Biological Sciences, University of Chester, Chester, UK
| | - Ellouise Leadbeater
- Department of Biological Sciences, Royal Holloway, University of London, Egham, UK
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3
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Seistrup AS, Choppin M, Govind S, Feldmeyer B, Kever M, Karaulanov E, Séguret A, Karunanithi S, Almeida MV, Ketting RF, Foitzik S. Age- and caste-independent piRNAs in the germline and miRNA profiles linked to caste and fecundity in the ant Temnothorax rugatulus. Mol Ecol 2023; 32:6027-6043. [PMID: 37830492 DOI: 10.1111/mec.17162] [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: 05/22/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
Social insects are models for studies of phenotypic plasticity. Ant queens and workers vary in fecundity and lifespan, which are enhanced and extended in queens. Yet, the regulatory mechanisms underlying this variation are not well understood. Ant queens live and reproduce for years, so that they need to protect their germline from transposable element (TE) activity, which may be redundant in short-lived, often sterile workers. We analysed the expression of two protective classes of small RNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), in various tissues, castes and age classes of the ant Temnothorax rugatulus. In queens, piRNAs were highly abundant in ovaries with TEs being their clear targets, with reduced but still detectable piRNA-specific ping-pong signatures in thorax and brains. piRNA pathway activity varied little with age in queens. Moreover, the reduced ovaries of workers also exhibited similar piRNA activity and this not only in young, fertile workers, but also in older foragers with regressed ovaries. Therefore, these ants protect their germline through piRNA activity, regardless of ovarian development, age or caste, even in sterile workers often considered the soma of the superorganism. Our tissue-specific miRNA analysis detected the expression of 304 miRNAs, of which 105 were expressed in all tissues, 10 enriched in the brain, three in the thorax, whereas 83 were ovarian-specific. We identified ovarian miRNAs whose expression was related to caste, fecundity and age, and which likely regulate group-specific gene expression. sRNA shifts in young- to middle-aged queens were minor, suggesting delayed senescence in this reproductive caste.
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Affiliation(s)
- Ann-Sophie Seistrup
- Institute of Molecular Biology, Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Marina Choppin
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Shamitha Govind
- Institute of Molecular Biology, Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Molecular Ecology, Frankfurt, Germany
| | - Marion Kever
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Alice Séguret
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Miguel V Almeida
- Institute of Molecular Biology, Mainz, Germany
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - René F Ketting
- Institute of Molecular Biology, Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
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4
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Negroni MA, LeBoeuf AC. Metabolic division of labor in social insects. CURRENT OPINION IN INSECT SCIENCE 2023; 59:101085. [PMID: 37454732 DOI: 10.1016/j.cois.2023.101085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 07/05/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Social insects are known for reproductive and behavioral division of labor, but little attention has been paid to metabolic forms of division of labor. Metabolic division of labor is the partitioning of complementary metabolic tasks between individuals, and it is widespread in social insects. We define two forms of metabolic division of labor, homosynergetic and heterosynergetic, we pinpoint trophallaxis, trophic eggs, and cannibalism as the primary transfers underlying the homosynergetic form and discuss their evolution. We argue that homosynergetic metabolic division of labor underpins fundamental aspects of colony physiology and may be a necessary feature of superorganismal systems, impacting many life history traits. Investigating metabolic division of labor is necessary to understand major evolutionary transition(s) to superorganismality in social insects.
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Affiliation(s)
- Matteo A Negroni
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| | - Adria C LeBoeuf
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
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5
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Jones BM, Rubin BER, Dudchenko O, Kingwell CJ, Traniello IM, Wang ZY, Kapheim KM, Wyman ES, Adastra PA, Liu W, Parsons LR, Jackson SR, Goodwin K, Davidson SM, McBride MJ, Webb AE, Omufwoko KS, Van Dorp N, Otárola MF, Pham M, Omer AD, Weisz D, Schraiber J, Villanea F, Wcislo WT, Paxton RJ, Hunt BG, Aiden EL, Kocher SD. Convergent and complementary selection shaped gains and losses of eusociality in sweat bees. Nat Ecol Evol 2023; 7:557-569. [PMID: 36941345 DOI: 10.1038/s41559-023-02001-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/18/2023] [Indexed: 03/23/2023]
Abstract
Sweat bees have repeatedly gained and lost eusociality, a transition from individual to group reproduction. Here we generate chromosome-length genome assemblies for 17 species and identify genomic signatures of evolutionary trade-offs associated with transitions between social and solitary living. Both young genes and regulatory regions show enrichment for these molecular patterns. We also identify loci that show evidence of complementary signals of positive and relaxed selection linked specifically to the convergent gains and losses of eusociality in sweat bees. This includes two pleiotropic proteins that bind and transport juvenile hormone (JH)-a key regulator of insect development and reproduction. We find that one of these proteins is primarily expressed in subperineurial glial cells that form the insect blood-brain barrier and that brain levels of JH vary by sociality. Our findings are consistent with a role of JH in modulating social behaviour and suggest that eusocial evolution was facilitated by alteration of the proteins that bind and transport JH, revealing how an ancestral developmental hormone may have been co-opted during one of life's major transitions. More broadly, our results highlight how evolutionary trade-offs have structured the molecular basis of eusociality in these bees and demonstrate how both directional selection and release from constraint can shape trait evolution.
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Affiliation(s)
- Beryl M Jones
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Benjamin E R Rubin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Olga Dudchenko
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX, USA
| | - Callum J Kingwell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Ian M Traniello
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Z Yan Wang
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Karen M Kapheim
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
- Department of Biology, Utah State University, Logan, UT, USA
| | - Eli S Wyman
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Per A Adastra
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Weijie Liu
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Lance R Parsons
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - S RaElle Jackson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Katharine Goodwin
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Shawn M Davidson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Matthew J McBride
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Chemistry, Princeton University, Princeton, NJ, USA
| | - Andrew E Webb
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Kennedy S Omufwoko
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Nikki Van Dorp
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Mauricio Fernández Otárola
- Biodiversity and Tropical Ecology Research Center (CIBET) and School of Biology, University of Costa Rica, San José, Costa Rica
| | - Melanie Pham
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Arina D Omer
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - David Weisz
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Joshua Schraiber
- Department of Biology, Temple University, Philadelphia, PA, USA
- Illumina Artificial Intelligence Laboratory, Illumina Inc, San Diego, CA, USA
| | - Fernando Villanea
- Department of Biology, Temple University, Philadelphia, PA, USA
- Department of Anthropology, University of Colorado Boulder, Boulder, CO, USA
| | - William T Wcislo
- Smithsonian Tropical Research Institute, Panama City, Republic of Panama
| | - Robert J Paxton
- Institute of Biology, Martin-Luther University Halle-Wittenberg, Halle, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Halle-Jena-Leipzig, Germany
| | - Brendan G Hunt
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - Erez Lieberman Aiden
- The Center for Genome Architecture, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX, USA
| | - Sarah D Kocher
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
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6
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Wyatt CDR, Bentley MA, Taylor D, Favreau E, Brock RE, Taylor BA, Bell E, Leadbeater E, Sumner S. Social complexity, life-history and lineage influence the molecular basis of castes in vespid wasps. Nat Commun 2023; 14:1046. [PMID: 36828829 PMCID: PMC9958023 DOI: 10.1038/s41467-023-36456-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 01/31/2023] [Indexed: 02/26/2023] Open
Abstract
A key mechanistic hypothesis for the evolution of division of labour in social insects is that a shared set of genes co-opted from a common solitary ancestral ground plan (a genetic toolkit for sociality) regulates caste differentiation across levels of social complexity. Using brain transcriptome data from nine species of vespid wasps, we test for overlap in differentially expressed caste genes and use machine learning models to predict castes using different gene sets. We find evidence of a shared genetic toolkit across species representing different levels of social complexity. We also find evidence of additional fine-scale differences in predictive gene sets, functional enrichment and rates of gene evolution that are related to level of social complexity, lineage and of colony founding. These results suggest that the concept of a shared genetic toolkit for sociality may be too simplistic to fully describe the process of the major transition to sociality.
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Affiliation(s)
- Christopher Douglas Robert Wyatt
- Centre for Biodiversity and Environment Research, Dept Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK.
| | - Michael Andrew Bentley
- Centre for Biodiversity and Environment Research, Dept Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK
| | - Daisy Taylor
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Emeline Favreau
- Centre for Biodiversity and Environment Research, Dept Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK
| | - Ryan Edward Brock
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
- Department of Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, Norfolk, NR4 7UH, UK
| | - Benjamin Aaron Taylor
- Centre for Biodiversity and Environment Research, Dept Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK
| | - Emily Bell
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Ellouise Leadbeater
- Department of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Seirian Sumner
- Centre for Biodiversity and Environment Research, Dept Genetics, Evolution & Environment, University College London, London, WC1E 6BT, UK.
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7
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Saleh NW, Henske J, Ramírez SR. Experimental disruption of social structure reveals totipotency in the orchid bee, Euglossa dilemma. Evolution 2022; 76:1529-1545. [PMID: 35589274 DOI: 10.1111/evo.14513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/29/2022] [Accepted: 04/07/2022] [Indexed: 01/22/2023]
Abstract
Eusociality has evolved multiple times across the insect phylogeny. Social insects with greater levels of social complexity tend to exhibit specialized castes with low levels of individual phenotypic plasticity. In contrast, species with simple social groups may consist of totipotent individuals that transition among behavioral and reproductive states. However, recent work has shown that in simple social groups, there can still be constraint on individual plasticity, caused by differences in maternal nourishment or social interaction. It is not well understood how these constraints arise, ultimately leading to the evolution of nonreproductive workers. Some species of orchid bees form social groups of a dominant and-one to two subordinate helpers where all individuals are reproductive. Females can also disperse to start their own nest as a solitary foundress, which includes a nonreproductive phase characterized by ovary inactivation, not typically expressed by subordinates. Little is known about individual flexibility across these trajectories. Here, using the orchid bee Euglossa dilemma, we assess the plasticity of subordinate helpers, finding that they are capable of the same behavioral, physiological, transcriptomic, and chemical changes seen in foundresses. Our results suggest that the lack of nonreproductive workers in E. dilemma is not due to a lack of subordinate plasticity.
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Affiliation(s)
- Nicholas W Saleh
- Entomology and Nematology Department, Fort Lauderdale Research and Education Center, University of Florida, Davie, Florida, USA.,Center for Population Biology, University of California, Davis, California, USA
| | - Jonas Henske
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr University Bochum, Bochum, Germany
| | - Santiago R Ramírez
- Center for Population Biology, University of California, Davis, California, USA
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8
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The emergence of a collective sensory response threshold in ant colonies. Proc Natl Acad Sci U S A 2022; 119:e2123076119. [PMID: 35653573 PMCID: PMC9191679 DOI: 10.1073/pnas.2123076119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SignificanceIn this study, we ask how ant colonies integrate information about the external environment with internal state parameters to produce adaptive, system-level responses. First, we show that colonies collectively evacuate the nest when the ground temperature becomes too warm. The threshold temperature for this response is a function of colony size, with larger colonies evacuating the nest at higher temperatures. The underlying dynamics can thus be interpreted as a decision-making process that takes both temperature (external environment) and colony size (internal state) into account. Using mathematical modeling, we show that these dynamics can emerge from a balance between local excitatory and global inhibitory forces acting between the ants. Our findings in ants parallel other complex biological systems like neural circuits.
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9
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Abouheif E. My road to the ants: A model clade for eco-evo-devo. Curr Top Dev Biol 2022; 147:231-290. [PMID: 35337451 DOI: 10.1016/bs.ctdb.2022.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This chapter is the story of how I pioneered ants as a system for studying eco-evo-devo, a field that integrates developmental biology with ecology and evolutionary biology. One aim of eco-evo-devo is to understand how the interactions between genes and their environments during development facilitates the origin and evolution of novel phenotypes. In a series of six parts, I review some of the key discoveries from my lab on how novel worker caste systems in ants--soldiers and supersoldiers--originated and evolved. I also discuss some of the ideas that emerged from these discoveries, including the role that polyphenisms, hidden developmental potentials, and rudimentary organs play in facilitating developmental and evolutionary change. As superorganisms, I argue that ants are uniquely positioned to reveal types of variation that are often difficult to observe in nature. In doing so, they have the potential to transform our view of biology and provide new perspectives in medicine, agriculture, and biodiversity conservation. With my story I hope to inspire the next generation of biologists to continue exploring the unknown regions of phenotypic space to solve some of our most pressing societal challenges.
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Affiliation(s)
- Ehab Abouheif
- Department of Biology, McGill University, Montreal, QC, Canada.
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10
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Hakala SM, Meurville MP, Stumpe M, LeBoeuf AC. Biomarkers in a socially exchanged /fluid reflect colony maturity, behavior, and distributed metabolism. eLife 2021; 10:74005. [PMID: 34725037 PMCID: PMC8608388 DOI: 10.7554/elife.74005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 10/15/2021] [Indexed: 12/24/2022] Open
Abstract
In cooperative systems exhibiting division of labor, such as microbial communities, multicellular organisms, and social insect colonies, individual units share costs and benefits through both task specialization and exchanged materials. Socially exchanged fluids, like seminal fluid and milk, allow individuals to molecularly influence conspecifics. Many social insects have a social circulatory system, where food and endogenously produced molecules are transferred mouth-to-mouth (stomodeal trophallaxis), connecting all the individuals in the society. To understand how these endogenous molecules relate to colony life, we used quantitative proteomics to investigate the trophallactic fluid within colonies of the carpenter ant Camponotus floridanus. We show that different stages of the colony life cycle circulate different types of proteins: young colonies prioritize direct carbohydrate processing; mature colonies prioritize accumulation and transmission of stored resources. Further, colonies circulate proteins implicated in oxidative stress, ageing, and social insect caste determination, potentially acting as superorganismal hormones. Brood-caring individuals that are also closer to the queen in the social network (nurses) showed higher abundance of oxidative stress-related proteins. Thus, trophallaxis behavior could provide a mechanism for distributed metabolism in social insect societies. The ability to thoroughly analyze the materials exchanged between cooperative units makes social insect colonies useful models to understand the evolution and consequences of metabolic division of labor at other scales. Division of labor is essential for cooperation, because groups can achieve more when individuals specialize in different tasks. This happens across the natural world, from different cells in organisms performing specific roles, to the individuals in an ant colony carrying out diverse duties. In both of these systems, individuals work together to ensure the survival of the collective unit – the body or the colony – instead of competing against each other. One of the main ways division of labor is evident within these two systems is regarding reproduction. Both in the body and in an ant colony, only one or a few individual units can reproduce, while the rest provide support. In the case of ant colonies, only queens and males reproduce, while the young workers nurse the brood and older workers forage for food. This intense cooperation requires close communication between individual units – in the case of some species of ants, by sharing fluids mouth-to-mouth. These fluids contain food but also many molecules produced by the ants themselves, including proteins. Given that both individuals and the colony as a whole change as they age – with workers acquiring new roles, and new queens and males only reared once the colony is mature – it is likely that the proteins transmitted in the fluid also change. To better understand whether the lifecycles of individuals and the age of the colony affect the fluids shared by carpenter ants Camponotus floridanus, Hakala et al. examined the ant-produced proteins in these fluids. This revealed differences in the proteins shared by young and mature colonies, and young nurse ants and older forager ants. In young colonies, the fluids contained proteins involved in fast sugar processing; while in mature colonies, the fluids contained more proteins to store nutrients, which help insect larvae grow into larger individuals, like queens. Young worker ants, who spend their time nursing the brood, produced more anti-aging proteins. This may be because these ants are in close contact with the queen, who lives much longer than the rest of the ants in the colony. Taken together, these observations suggest that ants divide the labor of metabolism, as well as work and reproduction. Dividing the labor of metabolism among individuals is one more similarity between ants and the cells of a multicellular organism, like a fly or a human. Division of labor allows the sharing of burden, with some individuals lightening the load of others. Understanding how ants achieve this by sharing fluids could shed new light on this complex exchange at other scales or in other organisms. By matching proteins to life stages, researchers have a starting point to examine individual molecules in more detail.
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Affiliation(s)
- Sanja M Hakala
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | | | - Michael Stumpe
- Metabolomics and Proteomics Platform, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Adria C LeBoeuf
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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11
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Loftus JC, Perez AA, Sih A. Task syndromes: linking personality and task allocation in social animal groups. Behav Ecol 2021; 32:1-17. [PMID: 33708004 PMCID: PMC7937036 DOI: 10.1093/beheco/araa083] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 08/04/2020] [Accepted: 08/07/2020] [Indexed: 11/12/2022] Open
Abstract
Studies of eusocial insects have extensively investigated two components of task allocation: how individuals distribute themselves among different tasks in a colony and how the distribution of labor changes to meet fluctuating task demand. While discrete age- and morphologically-based task allocation systems explain much of the social order in these colonies, the basis for task allocation in non-eusocial organisms and within eusocial castes remains unknown. Building from recent advances in the study of among-individual variation in behavior (i.e., animal personalities), we explore a potential mechanism by which individuality in behaviors unrelated to tasks can guide the developmental trajectories that lead to task specialization. We refer to the task-based behavioral syndrome that results from the correlation between the antecedent behavioral tendencies and task participation as a task syndrome. In this review, we present a framework that integrates concepts from a long history of task allocation research in eusocial organisms with recent findings from animal personality research to elucidate how task syndromes and resulting task allocation might manifest in animal groups. By drawing upon an extensive and diverse literature to evaluate the hypothesized framework, this review identifies future areas for study at the intersection of social behavior and animal personality.
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Affiliation(s)
- J C Loftus
- Department of Anthropology, University of California at Davis, Davis, CA, USA.,Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Radolfzell, Germany.,Department of Biology, University of Konstanz, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - A A Perez
- Department of Entomology, University of California at Davis, Davis, CA, USA
| | - A Sih
- Department of Environmental Science and Policy, University of California at Davis, Davis, CA, USA
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12
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Guoth AW, Chernyshova AM, Thompson GJ. Gene-regulatory context of honey bee worker sterility. Biosystems 2020; 198:104235. [PMID: 32882324 DOI: 10.1016/j.biosystems.2020.104235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/29/2020] [Accepted: 08/25/2020] [Indexed: 12/30/2022]
Abstract
The highly organized societies of the Western honey bee Apis mellifera feature a highly reproductive queen at the center of attention and a large cohort of daughters that suppress their own reproduction to help rear more sisters, some of whom become queens themselves. This reproductive altruism is peculiar because in theory it evolves via indirect selection on genes for altruism that are expressed in the sterile workers but not in the reproductive queens. In this study we attempt to situate lists of genes previously implicated in queenright worker sterility into a broader regulatory framework. To do so we use a model bee brain transcriptional regulatory network as a template to infer how sets of genes responsive to ovary-suppressing queen pheromone are functionally interconnected over the model's topology. We predict that genes jointly involved in the regulation of worker sterility should be tightly networked, relative to genes whose functions are unrelated to each other. We find that sets of mapped genes - ranging in size from 17 to 250 - are well dispersed across the network's substructural scaffolds, suggesting that ovary de-activation involves genes that reside within more than one transcriptional regulatory module. For some sets, however, this dispersion is biased into certain areas of the network's substructure. Our analysis identifies the regions enriched for sterility genes and likewise identifies local hub genes that are presumably critical to subnetwork function. Our work offers a glimpse into the gene regulatory context of honey bee worker sterility and uses this context to identify new candidate gene targets for functional analysis. Finally, to the extent that any sterility-related modules identified here have evolved via selection for worker altruism, we can assume that this selection was indirect and of the type specifically invoked by inclusive fitness theory.
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Affiliation(s)
- Alex W Guoth
- Biology Department, Western University, London, Ontario, N6A 5B7, Canada
| | - Anna M Chernyshova
- Biology Department, Western University, London, Ontario, N6A 5B7, Canada
| | - Graham J Thompson
- Biology Department, Western University, London, Ontario, N6A 5B7, Canada.
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13
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Nagel M, Qiu B, Brandenborg LE, Larsen RS, Ning D, Boomsma JJ, Zhang G. The gene expression network regulating queen brain remodeling after insemination and its parallel use in ants with reproductive workers. SCIENCE ADVANCES 2020; 6:6/38/eaaz5772. [PMID: 32938672 PMCID: PMC7494347 DOI: 10.1126/sciadv.aaz5772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 07/27/2020] [Indexed: 05/16/2023]
Abstract
Caste differentiation happens early in development to produce gynes as future colony germlines and workers as present colony soma. However, gynes need insemination to become functional queens, a transition that initiates reproductive role differentiation relative to unmated gynes. Here, we analyze the anatomy and transcriptomes of brains during this differentiation process within the reproductive caste of Monomorium pharaonis Insemination terminated brain growth, whereas unmated control gynes continued to increase brain volume. Transcriptomes revealed a specific gene regulatory network (GRN) mediating both brain anatomy changes and behavioral modifications. This reproductive role differentiation GRN hardly overlapped with the gyne-worker caste differentiation GRN, but appears to be also used by distantly related ants where workers became germline individuals after the queen caste was entirely or partially lost. The genes corazonin and neuroparsin A in the anterior neurosecretory cells were overexpressed in individuals with reduced or nonreproductive roles across all four ant species investigated.
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Affiliation(s)
- Manuel Nagel
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Bitao Qiu
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Centre for Social Evolution, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Lisa Eigil Brandenborg
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Rasmus Stenbak Larsen
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Dongdong Ning
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Jacobus Jan Boomsma
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Centre for Social Evolution, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Guojie Zhang
- Section for Ecology and Evolution, Department of Biology, Universitetsparken 15, University of Copenhagen, DK-2100 Copenhagen, Denmark.
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- China National GeneBank, BGI-Shenzhen, Jinsha Road, Shenzhen 518083, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China
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14
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Grodzicki P, Piechowicz B, Caputa M. The Effect of the Queen's Presence on Thermal Behavior and Locomotor Activity of Small Groups of Worker Honey Bees. INSECTS 2020; 11:E464. [PMID: 32717876 PMCID: PMC7469211 DOI: 10.3390/insects11080464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/17/2020] [Accepted: 07/21/2020] [Indexed: 11/16/2022]
Abstract
We examined effects of the queen's presence on diurnal rhythms of temperature preference (TP) and locomotor activity (LA) in worker honeybees' groups. TP and LA of six queenless and six queenright (with the queen) groups of bees, consisting of 7-8 worker bees, were recorded in a thermal gradient system for four days, under light to darkness (LD) 12:12 photoperiod. The same experiments were conducted on five virgin queens (of the same age as those in the queenright groups), which were placed individually in the gradient chambers. The single virgin queens showed signs of distress and no rhythms of TP and LA. In contrast, there were diurnal rhythms of TP and LA in both group variants with daytime activity and nighttime rest. However, the queen's presence exerted a strong calming effect, reducing LA of bees both at day- and nighttime. The nighttime minimum LA of queenright groups was five times lower than that in queenless groups. Moreover, there was a reversal of the diurnal pattern of TP in queenright groups. The results are discussed in terms of the bee colony organization as a superorganism.
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Affiliation(s)
- Przemysław Grodzicki
- Department of Animal Physiology and Neurobiology, Faculty of Biological and Veterinary Sciences, N. Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland;
| | - Bartosz Piechowicz
- Department of Animal Physiology and Reproduction, Faculty of Biotechnology, University of Rzeszów, Werynia 2, 36-100 Kolbuszowa, Poland;
| | - Michał Caputa
- Department of Animal Physiology and Neurobiology, Faculty of Biological and Veterinary Sciences, N. Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland;
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15
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Lehtonen J, Helanterä H. Superorganismal anisogamy: queen-male dimorphism in eusocial insects. Proc Biol Sci 2020; 287:20200635. [PMID: 32517607 PMCID: PMC7341914 DOI: 10.1098/rspb.2020.0635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/17/2020] [Indexed: 12/02/2022] Open
Abstract
Colonies of insects such as ants and honeybees are commonly viewed as 'superorganisms', with division of labour between reproductive 'germline-like' queens and males and 'somatic' workers. On this view, properties of the superorganismal colony are comparable with those of solitary organisms to such an extent that the colony itself can be viewed as a unit analogous to an organism. Thus, the concept of a superorganism can be useful as a guide to thinking about life history and allocation traits of colonies as a whole. A pattern that seems to reoccur in insects with superorganismal societies is size dimorphism between queens and males, where queens tend to be larger than males. It has been proposed that this is analogous to the phenomenon of anisogamy at the level of gametes in organisms with separate sexes; more specifically, it is suggested that this caste dimorphism may have evolved via similar selection pressures as gamete dimorphism arises in the 'gamete competition' theory for the evolution of anisogamy. In this analogy, queens are analogous to female gametes, males are analogous to male gametes, and colony survival is analogous to zygote survival in gamete competition theory. Here, we explore if this question can be taken beyond an analogy, and whether a mathematical model at the superorganism level, analogous to gamete competition at the organism level, may explain the caste dimorphism seen in superorganismal insects. We find that the central theoretical idea holds, but that there are also significant differences between the way this generalized 'propagule competition' theory operates at the levels of solitary organisms and superorganisms. In particular, we find that the theory can explain superorganismal caste dimorphism, but compared with anisogamy evolution, a central coevolutionary link is broken, making the requirements for the theory to work less stringent than those found for the evolution of anisogamy.
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Affiliation(s)
- Jussi Lehtonen
- Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Heikki Helanterä
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
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16
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Friedman DA, Johnson BR, Linksvayer TA. Distributed physiology and the molecular basis of social life in eusocial insects. Horm Behav 2020; 122:104757. [PMID: 32305342 DOI: 10.1016/j.yhbeh.2020.104757] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 03/30/2020] [Accepted: 04/06/2020] [Indexed: 12/24/2022]
Abstract
The traditional focus of physiological and functional genomic research is on molecular processes that play out within a single multicellular organism. In the colonial (eusocial) insects such as ants, bees, and termites, molecular and behavioral responses of interacting nestmates are tightly linked, and key physiological processes are regulated at the scale of the colony. Such colony-level physiological processes regulate nestmate physiology in a distributed fashion, through various social communication mechanisms. As a result of physiological decentralization over evolutionary time, organismal mechanisms, for example related to pheromone detection, hormone signaling, and neural signaling pathways, are deployed in novel contexts to influence nestmate and colony traits. Here we explore how functional genomic, physiological, and behavioral studies can benefit from considering the traits of eusocial insects in this light. We highlight functional genomic work exploring how nestmate-level and colony-level traits arise and are influenced by interactions among physiologically-specialized nestmates of various developmental stages. We also consider similarities and differences between nestmate-level (organismal) and colony-level (superorganismal) physiological processes, and make specific hypotheses regarding the physiology of eusocial taxa. Integrating theoretical models of distributed systems with empirical functional genomics approaches will be useful in addressing fundamental questions related to the evolution of eusociality and collective behavior in natural systems.
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Affiliation(s)
- D A Friedman
- University of California, Davis, Department of Entomology, Davis, CA 95616, United States of America.
| | - B R Johnson
- University of California, Davis, Department of Entomology, Davis, CA 95616, United States of America
| | - T A Linksvayer
- University of Pennsylvania, Department of Biology, Pennsylvania, PA 19104, United States of America
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17
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Friedman DA, York RA, Hilliard AT, Gordon DM. Gene expression variation in the brains of harvester ant foragers is associated with collective behavior. Commun Biol 2020; 3:100. [PMID: 32139795 PMCID: PMC7057964 DOI: 10.1038/s42003-020-0813-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 02/10/2020] [Indexed: 01/10/2023] Open
Abstract
Natural selection on collective behavior acts on variation among colonies in behavior that is associated with reproductive success. In the red harvester ant (Pogonomyrmex barbatus), variation among colonies in the collective regulation of foraging in response to humidity is associated with colony reproductive success. We used RNA-seq to examine gene expression in the brains of foragers in a natural setting. We find that colonies differ in the expression of neurophysiologically-relevant genes in forager brains, and a fraction of these gene expression differences are associated with two colony traits: sensitivity of foraging activity to humidity, and forager brain dopamine to serotonin ratio. Loci that were correlated with colony behavioral differences were enriched in neurotransmitter receptor signaling & metabolic functions, tended to be more central to coexpression networks, and are evolving under higher protein-coding sequence constraint. Natural selection may shape colony foraging behavior through variation in gene expression.
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Affiliation(s)
| | | | | | - Deborah M Gordon
- Stanford University, Department of Biology, Stanford, CA, 94305, USA.
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18
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Tong C, Najm GM, Pinter-Wollman N, Pruitt JN, Linksvayer TA. Comparative Genomics Identifies Putative Signatures of Sociality in Spiders. Genome Biol Evol 2020; 12:122-133. [PMID: 31960912 PMCID: PMC7108510 DOI: 10.1093/gbe/evaa007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2020] [Indexed: 12/15/2022] Open
Abstract
Comparative genomics has begun to elucidate the genomic basis of social life in insects, but insight into the genomic basis of spider sociality has lagged behind. To begin, to characterize genomic signatures associated with the evolution of social life in spiders, we performed one of the first spider comparative genomics studies including five solitary species and two social species, representing two independent origins of sociality in the genus Stegodyphus. We found that the two social spider species had a large expansion of gene families associated with transport and metabolic processes and an elevated genome-wide rate of molecular evolution compared with the five solitary spider species. Genes that were rapidly evolving in the two social species relative to the five solitary species were enriched for transport, behavior, and immune functions, whereas genes that were rapidly evolving in the solitary species were enriched for energy metabolism processes. Most rapidly evolving genes in the social species Stegodyphus dumicola were broadly expressed across four tissues and enriched for transport functions, but 12 rapidly evolving genes showed brain-specific expression and were enriched for social behavioral processes. Altogether, our study identifies putative genomic signatures and potential candidate genes associated with spider sociality. These results indicate that future spider comparative genomic studies, including broader sampling and additional independent origins of sociality, can further clarify the genomic causes and consequences of social life.
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Affiliation(s)
- Chao Tong
- Department of Biology, University of Pennsylvania
| | - Gabriella M Najm
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles
| | - Jonathan N Pruitt
- Department of Psychology, Neurobiology & Behaviour, McMaster University, Hamilton, Ontario, Canada
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19
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Canciani M, Arnellos A, Moreno A. Revising the Superorganism: An Organizational Approach to Complex Eusociality. Front Psychol 2019; 10:2653. [PMID: 31849768 PMCID: PMC6901679 DOI: 10.3389/fpsyg.2019.02653] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/11/2019] [Indexed: 12/03/2022] Open
Abstract
Eusociality is broadly defined as: colonies consisting of overlapping generations, cooperative brood care, and a reproductive division of labor where sterile (or non-reproductive) workers help the reproductive members. Colonies of many complex eusocial insect species (e.g., ants, bees, termites) exhibit traits, at the collective level, that are more analogous to biological individuals rather than to groups. Indeed, due to this, colonies of the most complex species are typically a unit of selection, which has led many authors to once again apply the concept of the superorganism to eusocial insects. However, unlike Wheeler, who originally employed the concept from a physiological and evolutionary perspective, today the superorganism is typically understood only from an evolutionary perspective, using group selection. This is because of the widely held view that eusocial colonies are self-organized systems. According to this view, even the most complex eusocial systems can be explained by appealing to a set of local interactions between parts of an initially disordered system (i.e., self-organization), without the need of any hierarchical control. In this paper, we challenge the mainstream view that hierarchical control and regulation does not occur, or is not necessary, in complex eusocial colonies. Using a case study of honey bees (Apis mellifera), we develop an alternative to the self-organization approach that focuses on the hierarchical nature of the organization of complex eusocial systems—that we refer to as the hierarchical-organizational approach. In addition, we analyze how colonies of eusocial insects show a complex set of interactions between the different organisms that bring forth a new cohesive collective organization, and how in turn the constitutive entities of this collective organization are transformed in this process. This paper argues that an inter-identity (namely the superorganism) emerges at the collective level in complex eusocial colonies, such as honey bees, due to the hierarchically organized network of interactions within the colony.
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Affiliation(s)
- Mark Canciani
- Department of Logic and Philosophy of Science, IAS-Research Centre for Life, Mind and Society, University of the Basque Country, Donostia-San Sebastián, Spain
| | - Argyris Arnellos
- Department of Logic and Philosophy of Science, IAS-Research Centre for Life, Mind and Society, University of the Basque Country, Donostia-San Sebastián, Spain.,Complex Systems and Service Design Laboratory, Department of Product and Systems Design Engineering, University of the Aegean, Mytilene, Greece
| | - Alvaro Moreno
- Department of Logic and Philosophy of Science, IAS-Research Centre for Life, Mind and Society, University of the Basque Country, Donostia-San Sebastián, Spain
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20
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Nagari M, Gera A, Jonsson S, Bloch G. Bumble Bee Workers Give Up Sleep to Care for Offspring that Are Not Their Own. Curr Biol 2019; 29:3488-3493.e4. [DOI: 10.1016/j.cub.2019.07.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/09/2019] [Accepted: 07/31/2019] [Indexed: 01/26/2023]
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21
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Pernu TK, Helanterä H. Genetic relatedness and its causal role in the evolution of insect societies. J Biosci 2019. [DOI: 10.1007/s12038-019-9894-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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22
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Linksvayer TA, Johnson BR. Re-thinking the social ladder approach for elucidating the evolution and molecular basis of insect societies. CURRENT OPINION IN INSECT SCIENCE 2019; 34:123-129. [PMID: 31401545 DOI: 10.1016/j.cois.2019.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/21/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
The evolution of large insect societies is a major evolutionary transition that occurred in the long-extinct ancestors of termites, ants, corbiculate bees, and vespid wasps. Researchers have long used 'social ladder thinking': assuming progressive stepwise phenotypic evolution and asserting that extant species with simple societies (e.g. some halictid bees) represent the ancestors of species with complex societies, and thus provide insight into general early steps of eusocial evolution. We discuss how this is inconsistent with data and modern evolutionary 'tree thinking'. Phylogenetic comparative methods with broad sampling provide the best means to make rigorous inferences about ancestral traits and evolutionary transitions that occurred within each lineage, and to determine whether consistent phenotypic and genomic changes occurred across independent lineages.
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Affiliation(s)
| | - Brian R Johnson
- Department of Entomology and Nematology, University of California Davis, United States
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23
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Taylor BA, Reuter M, Sumner S. Patterns of reproductive differentiation and reproductive plasticity in the major evolutionary transition to superorganismality. CURRENT OPINION IN INSECT SCIENCE 2019; 34:40-47. [PMID: 31247416 DOI: 10.1016/j.cois.2019.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/05/2019] [Accepted: 02/21/2019] [Indexed: 06/09/2023]
Abstract
Major evolutionary transitions in individuality are characterised by the formation of new levels of biological complexity from the cooperation of previously independent lower-level units. The evolution of superorganismality in insects is one such major transition, and is characterised by an extreme division of reproductive labour between ancestrally autonomous units, in the form of queen and worker castes. Here, we discuss the nature of plasticity in the emergence of castes across the major transition to superorganismality in insects. We identify key changes in plasticity which act at different levels of selection: a loss of reproductivity plasticity at the individual level is matched by a gain in plasticity at the colony level. Taking multi-level selection into consideration has important implications for formulating testable hypotheses regarding the nature of plasticity in a major transition from a lower to a higher level of biological complexity.
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Affiliation(s)
- Benjamin A Taylor
- Centre for Biodiversity & Environment Research, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Max Reuter
- Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Seirian Sumner
- Centre for Biodiversity & Environment Research, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, United Kingdom.
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24
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Calkins TL, Tamborindeguy C, Pietrantonio PV. GPCR annotation, G proteins, and transcriptomics of fire ant (Solenopsis invicta) queen and worker brain: An improved view of signaling in an invasive superorganism. Gen Comp Endocrinol 2019; 278:89-103. [PMID: 30576645 DOI: 10.1016/j.ygcen.2018.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 12/13/2018] [Accepted: 12/17/2018] [Indexed: 10/27/2022]
Abstract
Knowledge of G protein-coupled receptors (GPCRs) and their signaling modalities is crucial to advancing insect endocrinology, specifically in highly successful invasive social insects, such as the red imported fire ant, Solenopsis invicta Buren. In the first published draft genome of S. invicta, emphasis was placed on the annotation of olfactory receptors, and only the number of predicted GPCR genes was reported. Without an organized and curated resource for GPCRs, it will be difficult to test hypotheses on the endocrine role of neuropeptide hormones, or the function of neurotransmitters and neuromodulators. Therefore, we mined the S. invicta genome for GPCRs and found 324 predicted transcripts encoded by 125 predicted loci and improved the annotation of 55 of these loci. Among them are sixteen GPCRs that are currently annotated as "uncharacterized proteins". Further, the phylogenetic analysis of class A neuropeptide receptors presented here and the comparative listing of GPCRs in the hymenopterans S. invicta, Apis mellifera (both eusocial), Nasonia vitripennis (solitary), and the solitary model dipteran Drosophila melanogaster will facilitate comparative endocrinological studies related to social insect evolution and diversity. We compiled the 24 G protein transcripts predicted (15 α, 7 β, and 2 γ) from 12 G protein genes (5 α, 5 β, and 2 γ). Reproductive division of labor is extreme in this ant species, therefore, we compared GPCR and G protein gene expression among worker, mated queen and alate virgin queen ant brain transcriptomes. Transcripts for ten GPCRs and two G proteins were differentially expressed between queen and worker brains. The differentially expressed GPCRs are candidate receptors to explore hypotheses on division of labor in this species.
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Affiliation(s)
- Travis L Calkins
- Department of Entomology, Texas A&M University, College Station, TX 77843-2475, USA
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25
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Harpur BA, Guarna MM, Huxter E, Higo H, Moon KM, Hoover SE, Ibrahim A, Melathopoulos AP, Desai S, Currie RW, Pernal SF, Foster LJ, Zayed A. Integrative Genomics Reveals the Genetics and Evolution of the Honey Bee's Social Immune System. Genome Biol Evol 2019; 11:937-948. [PMID: 30768172 PMCID: PMC6447389 DOI: 10.1093/gbe/evz018] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2019] [Indexed: 12/13/2022] Open
Abstract
Social organisms combat pathogens through individual innate immune responses or through social immunity—behaviors among individuals that limit pathogen transmission within groups. Although we have a relatively detailed understanding of the genetics and evolution of the innate immune system of animals, we know little about social immunity. Addressing this knowledge gap is crucial for understanding how life-history traits influence immunity, and identifying if trade-offs exist between innate and social immunity. Hygienic behavior in the Western honey bee, Apis mellifera, provides an excellent model for investigating the genetics and evolution of social immunity in animals. This heritable, colony-level behavior is performed by nurse bees when they detect and remove infected or dead brood from the colony. We sequenced 125 haploid genomes from two artificially selected highly hygienic populations and a baseline unselected population. Genomic contrasts allowed us to identify a minimum of 73 genes tentatively associated with hygienic behavior. Many genes were within previously discovered QTLs associated with hygienic behavior and were predictive of hygienic behavior within the unselected population. These genes were often involved in neuronal development and sensory perception in solitary insects. We found that genes associated with hygienic behavior have evidence of positive selection within honey bees (Apis), supporting the hypothesis that social immunity contributes to fitness. Our results indicate that genes influencing developmental neurobiology and behavior in solitary insects may have been co-opted to give rise to a novel and adaptive social immune phenotype in honey bees.
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Affiliation(s)
- Brock A Harpur
- Department of Entomology, Purdue University.,Department of Biology, York University, Toronto, Ontario, Canada
| | - Maria Marta Guarna
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.,Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, Alberta, Canada
| | | | - Heather Higo
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kyung-Mee Moon
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shelley E Hoover
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada.,Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, Alberta, Canada.,Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, Alberta, Canada
| | - Abdullah Ibrahim
- Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, Alberta, Canada
| | - Andony P Melathopoulos
- Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, Alberta, Canada.,Department of Horticulture, College of Agricultural Sciences, Oregon State University
| | - Suresh Desai
- Department of Entomology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert W Currie
- Department of Entomology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Stephen F Pernal
- Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, Alberta, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amro Zayed
- Department of Biology, York University, Toronto, Ontario, Canada
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26
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Warner MR, Mikheyev AS, Linksvayer TA. Transcriptomic basis and evolution of the ant nurse-larval social interactome. PLoS Genet 2019; 15:e1008156. [PMID: 31107868 DOI: 10.1101/514356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/31/2019] [Accepted: 04/24/2019] [Indexed: 05/20/2023] Open
Abstract
Development is often strongly regulated by interactions among close relatives, but the underlying molecular mechanisms are largely unknown. In eusocial insects, interactions between caregiving worker nurses and larvae regulate larval development and resultant adult phenotypes. Here, we begin to characterize the social interactome regulating ant larval development by collecting and sequencing the transcriptomes of interacting nurses and larvae across time. We find that the majority of nurse and larval transcriptomes exhibit parallel expression dynamics across larval development. We leverage this widespread nurse-larva gene co-expression to infer putative social gene regulatory networks acting between nurses and larvae. Genes with the strongest inferred social effects tend to be peripheral elements of within-tissue regulatory networks and are often known to encode secreted proteins. This includes interesting candidates such as the nurse-expressed giant-lens, which may influence larval epidermal growth factor signaling, a pathway known to influence various aspects of insect development. Finally, we find that genes with the strongest signatures of social regulation tend to experience relaxed selective constraint and are evolutionarily young. Overall, our study provides a first glimpse into the molecular and evolutionary features of the social mechanisms that regulate all aspects of social life.
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Affiliation(s)
- Michael R Warner
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology, Onna, Okinawa, Japan
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Timothy A Linksvayer
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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27
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Warner MR, Mikheyev AS, Linksvayer TA. Transcriptomic basis and evolution of the ant nurse-larval social interactome. PLoS Genet 2019; 15:e1008156. [PMID: 31107868 PMCID: PMC6544314 DOI: 10.1371/journal.pgen.1008156] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/31/2019] [Accepted: 04/24/2019] [Indexed: 12/13/2022] Open
Abstract
Development is often strongly regulated by interactions among close relatives, but the underlying molecular mechanisms are largely unknown. In eusocial insects, interactions between caregiving worker nurses and larvae regulate larval development and resultant adult phenotypes. Here, we begin to characterize the social interactome regulating ant larval development by collecting and sequencing the transcriptomes of interacting nurses and larvae across time. We find that the majority of nurse and larval transcriptomes exhibit parallel expression dynamics across larval development. We leverage this widespread nurse-larva gene co-expression to infer putative social gene regulatory networks acting between nurses and larvae. Genes with the strongest inferred social effects tend to be peripheral elements of within-tissue regulatory networks and are often known to encode secreted proteins. This includes interesting candidates such as the nurse-expressed giant-lens, which may influence larval epidermal growth factor signaling, a pathway known to influence various aspects of insect development. Finally, we find that genes with the strongest signatures of social regulation tend to experience relaxed selective constraint and are evolutionarily young. Overall, our study provides a first glimpse into the molecular and evolutionary features of the social mechanisms that regulate all aspects of social life.
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Affiliation(s)
- Michael R. Warner
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alexander S. Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology, Onna, Okinawa, Japan
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Timothy A. Linksvayer
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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28
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Comparative transcriptomics of social insect queen pheromones. Nat Commun 2019; 10:1593. [PMID: 30962449 PMCID: PMC6453924 DOI: 10.1038/s41467-019-09567-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
Queen pheromones are chemical signals that mediate reproductive division of labor in eusocial animals. Remarkably, queen pheromones are composed of identical or chemically similar compounds in some ants, wasps and bees, even though these taxa diverged >150MYA and evolved queens and workers independently. Here, we measure the transcriptomic consequences of experimental exposure to queen pheromones in workers from two ant and two bee species (genera: Lasius, Apis, Bombus), and test whether they are similar across species. Queen pheromone exposure affected transcription and splicing at many loci. Many genes responded consistently in multiple species, and the set of pheromone-sensitive genes was enriched for functions relating to lipid biosynthesis and transport, olfaction, production of cuticle, oogenesis, and histone (de)acetylation. Pheromone-sensitive genes tend to be evolutionarily ancient, positively selected, peripheral in the gene coexpression network, hypomethylated, and caste-specific in their expression. Our results reveal how queen pheromones achieve their effects, and suggest that ants and bees use similar genetic modules to achieve reproductive division of labor.
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29
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Fujisawa R, Ichinose G, Dobata S. Regulatory mechanism predates the evolution of self-organizing capacity in simulated ant-like robots. Commun Biol 2019; 2:25. [PMID: 30675523 PMCID: PMC6338667 DOI: 10.1038/s42003-018-0276-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 12/19/2018] [Indexed: 11/12/2022] Open
Abstract
The evolution of complexity is one of the prime features of life on Earth. Although well accepted as the product of adaptation, the dynamics underlying the evolutionary build-up of complex adaptive systems remains poorly resolved. Using simulated robot swarms that exhibit ant-like group foraging with trail pheromones, we show that their self-organizing capacity paradoxically involves regulatory behavior that arises in advance. We focus on a traffic rule on their foraging trail as a regulatory trait. We allow the simulated robot swarms to evolve pheromone responsiveness and traffic rules simultaneously. In most cases, the traffic rule, initially arising as selectively neutral component behaviors, assists the group foraging system to bypass a fitness valley caused by overcrowding on the trail. Our study reveals a hitherto underappreciated role of regulatory mechanisms in the origin of complex adaptive systems, as well as highlights the importance of embodiment in the study of their evolution.
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Affiliation(s)
- Ryusuke Fujisawa
- Department of Systems Design and Informatics, Kyushu Institute of Technology, Iizuka, Fukuoka, 820-8502 Japan
| | - Genki Ichinose
- Department of Mathematical and Systems Engineering, Shizuoka University, Hamamatsu, Shizuoka, 432-8561 Japan
| | - Shigeto Dobata
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto, 606-8502 Japan
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30
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31
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Faragalla KM, Chernyshova AM, Gallo AJ, Thompson GJ. From gene list to gene network: Recognizing functional connections that regulate behavioral traits. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2018; 330:317-329. [DOI: 10.1002/jez.b.22829] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 09/10/2018] [Indexed: 12/27/2022]
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32
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Walsh JT, Signorotti L, Linksvayer TA, d'Ettorre P. Phenotypic correlation between queen and worker brood care supports the role of maternal care in the evolution of eusociality. Ecol Evol 2018; 8:10409-10415. [PMID: 30464814 PMCID: PMC6238135 DOI: 10.1002/ece3.4475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 11/16/2022] Open
Abstract
Cooperative brood care by siblings, a defining feature of eusociality, is hypothesized to be evolutionarily derived from maternal care via shifts in the timing of the expression of genes underlying maternal care. If sibling and maternal care share a genetic basis, the two behaviors are expected to be genetically and phenotypically correlated. We tested this prediction in the black garden ant Lasius niger by quantifying the brood retrieval rate of queens and their first and later generation worker offspring. Brood retrieval rate of queens was positively phenotypically correlated with the brood retrieval rate of first generation but not with later generation workers. The difference between first and later generation workers could be due to the stronger similarity in care behavior provided by queens and first generation workers compared to later generations. Furthermore, we found that queen retrieval rate was positively correlated with colony productivity, suggesting that natural selection is acting on maternal care. Overall, our results support the idea of a shared genetic basis between maternal and sibling care as well as queen and worker traits more generally, which has implications for the role of intercaste correlations in the evolution of queen and worker traits and eusociality.
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Affiliation(s)
- Justin T. Walsh
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Lisa Signorotti
- Laboratory of Experimental and Comparative Ethology (LEEC)University of Paris 13Sorbonne Paris CitéFrance
| | | | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology (LEEC)University of Paris 13Sorbonne Paris CitéFrance
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33
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Friedman DA, Pilko A, Skowronska-Krawczyk D, Krasinska K, Parker JW, Hirsh J, Gordon DM. The Role of Dopamine in the Collective Regulation of Foraging in Harvester Ants. iScience 2018; 8:283-294. [PMID: 30270022 PMCID: PMC6205345 DOI: 10.1016/j.isci.2018.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/04/2018] [Accepted: 09/03/2018] [Indexed: 01/09/2023] Open
Abstract
Colonies of the red harvester ant (Pogonomyrmex barbatus) differ in how they regulate collective foraging activity in response to changes in humidity. We used transcriptomic, physiological, and pharmacological experiments to investigate the molecular basis of this ecologically important variation in collective behavior among colonies. RNA sequencing of forager brain tissue showed an association between colony foraging activity and differential expression of transcripts related to biogenic amine and neurohormonal metabolism and signaling. In field experiments, pharmacological increases in forager brain dopamine titer caused significant increases in foraging activity. Colonies that were naturally most sensitive to humidity were significantly more responsive to the stimulatory effect of exogenous dopamine. In addition, forager brain tissue significantly varied among colonies in biogenic amine content. Neurophysiological variation among colonies associated with individual forager sensitivity to humidity may reflect the heritable molecular variation on which natural selection acts to shape the collective regulation of foraging.
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Affiliation(s)
- Daniel A Friedman
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Anna Pilko
- Department of Chemistry and Biochemistry and the Institute for Quantitative and Computational Biosciences (QCB), University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Dorota Skowronska-Krawczyk
- Shiley Eye Institute, Richard C. Atkinson Lab for Regenerative Ophthalmology, Department of Ophthalmology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Karolina Krasinska
- Stanford University Mass Spectrometry, Stanford University, Stanford, CA 94305, USA
| | - Jacqueline W Parker
- Department of Biology, University of Virginia, Charlottesville, Charlottesville, VA 22904, USA
| | - Jay Hirsh
- Department of Biology, University of Virginia, Charlottesville, Charlottesville, VA 22904, USA
| | - Deborah M Gordon
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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34
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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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35
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van Dooremalen C, Cornelissen B, Poleij-Hok-Ahin C, Blacquière T. Single and interactive effects of Varroa destructor
, Nosema
spp., and imidacloprid on honey bee colonies (Apis mellifera
). Ecosphere 2018. [DOI: 10.1002/ecs2.2378] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Coby van Dooremalen
- Bees@wur; Wageningen Plant Research; Wageningen University and Research; Droevendaalsesteeg 1 Wageningen 6708 PB The Netherlands
| | - Bram Cornelissen
- Bees@wur; Wageningen Plant Research; Wageningen University and Research; Droevendaalsesteeg 1 Wageningen 6708 PB The Netherlands
| | - Chula Poleij-Hok-Ahin
- Bees@wur; Wageningen Plant Research; Wageningen University and Research; Droevendaalsesteeg 1 Wageningen 6708 PB The Netherlands
| | - Tjeerd Blacquière
- Bees@wur; Wageningen Plant Research; Wageningen University and Research; Droevendaalsesteeg 1 Wageningen 6708 PB The Netherlands
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36
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Ma R, Villar G, Grozinger CM, Rangel J. Larval pheromones act as colony-wide regulators of collective foraging behavior in honeybees. Behav Ecol 2018. [DOI: 10.1093/beheco/ary090] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- R Ma
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - G Villar
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, PA, USA
| | - C M Grozinger
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, PA, USA
| | - J Rangel
- Department of Entomology, Texas A&M University, College Station, TX, USA
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37
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Genetic relatedness does not predict the queen’s successors in the primitively eusocial wasp, Ropalidia marginata. J Genet 2018. [DOI: 10.1007/s12041-018-0926-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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38
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Chemical Ecology and Sociality in Aphids: Opportunities and Directions. J Chem Ecol 2018; 44:770-784. [PMID: 29637490 DOI: 10.1007/s10886-018-0955-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/13/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
Aphids have long been recognized as good phytochemists. They are small sap-feeding plant herbivores with complex life cycles that can involve cyclical parthenogenesis and seasonal host plant alternation, and most are plant specialists. Aphids have distinctive traits for identifying and exploiting their host plants, including the expression of polyphenisms, a form of discrete phenotypic plasticity characteristic of insects, but taken to extreme in aphids. In a relatively small number of species, a social polyphenism occurs, involving sub-adult "soldiers" that are behaviorally or morphologically specialized to defend their nestmates from predators. Soldiers are sterile in many species, constituting a form of eusociality and reproductive division of labor that bears striking resemblances with other social insects. Despite a wealth of knowledge about the chemical ecology of non-social aphids and their phytophagous lifestyles, the molecular and chemoecological mechanisms involved in social polyphenisms in aphids are poorly understood. We provide a brief primer on aspects of aphid life cycles and chemical ecology for the non-specialists, and an overview of the social biology of aphids, with special attention to chemoecological perspectives. We discuss some of our own efforts to characterize how host plant chemistry may shape social traits in aphids. As good phytochemists, social aphids provide a bridge between the study of insect social evolution sociality, and the chemical ecology of plant-insect interactions. Aphids provide many promising opportunities for the study of sociality in insects, and to understand both the convergent and novel traits that characterize complex sociality on plants.
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39
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Waters JS, Ochs A, Fewell JH, Harrison JF. Differentiating causality and correlation in allometric scaling: ant colony size drives metabolic hypometry. Proc Biol Sci 2018; 284:rspb.2016.2582. [PMID: 28228514 DOI: 10.1098/rspb.2016.2582] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/01/2017] [Indexed: 11/12/2022] Open
Abstract
Metabolic rates of individual animals and social insect colonies generally scale hypometrically, with mass-specific metabolic rates decreasing with increasing size. Although this allometry has wide ranging effects on social behaviour, ecology and evolution, its causes remain controversial. Because it is difficult to experimentally manipulate body size of organisms, most studies of metabolic scaling depend on correlative data, limiting their ability to determine causation. To overcome this limitation, we experimentally reduced the size of harvester ant colonies (Pogonomyrmex californicus) and quantified the consequent increase in mass-specific metabolic rates. Our results clearly demonstrate a causal relationship between colony size and hypometric changes in metabolic rate that could not be explained by changes in physical density. These findings provide evidence against prominent models arguing that the hypometric scaling of metabolic rate is primarily driven by constraints on resource delivery or surface area/volume ratios, because colonies were provided with excess food and colony size does not affect individual oxygen or nutrient transport. We found that larger colonies had lower median walking speeds and relatively more stationary ants and including walking speed as a variable in the mass-scaling allometry greatly reduced the amount of residual variation in the model, reinforcing the role of behaviour in metabolic allometry. Following the experimental size reduction, however, the proportion of stationary ants increased, demonstrating that variation in locomotory activity cannot solely explain hypometric scaling of metabolic rates in these colonies. Based on prior studies of this species, the increase in metabolic rate in size-reduced colonies could be due to increased anabolic processes associated with brood care and colony growth.
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Affiliation(s)
- James S Waters
- Department of Biology, Providence College, Providence, RI 02918, USA
| | - Alison Ochs
- Mount Holyoke College, South Hadley, MA 01075, USA
| | - Jennifer H Fewell
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4601, USA
| | - Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4601, USA
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40
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Sasaki T, Pratt SC. The Psychology of Superorganisms: Collective Decision Making by Insect Societies. ANNUAL REVIEW OF ENTOMOLOGY 2018; 63:259-275. [PMID: 28977775 DOI: 10.1146/annurev-ento-020117-043249] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Under the superorganism concept, insect societies are so tightly integrated that they possess features analogous to those of single organisms, including collective cognition. If so, colony function might fruitfully be studied using methods developed to understand individual animals. Here, we review research that uses psychological approaches to understand decision making by colonies. The application of neural models to collective choice shows fundamental similarities between how brains and colonies balance speed/accuracy trade-offs in decision making. Experimental analyses have explored collective rationality, cognitive capacity, and perceptual discrimination at both individual and colony levels. A major theme is the emergence of improved colony-level function from interactions among relatively less capable individuals. However, colonies also encounter performance costs due to their reliance on positive feedback, which generates consensus but can also amplify errors. Collective learning is a nascent field for the further application of psychological methods to colonies. The research strategy reviewed here shows how the superorganism concept can serve as more than an illustrative analogy.
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Affiliation(s)
- Takao Sasaki
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom;
| | - Stephen C Pratt
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA;
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41
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Pracana R, Levantis I, Martínez‐Ruiz C, Stolle E, Priyam A, Wurm Y. Fire ant social chromosomes: Differences in number, sequence and expression of odorant binding proteins. Evol Lett 2017; 1:199-210. [PMID: 30283649 PMCID: PMC6121795 DOI: 10.1002/evl3.22] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/17/2017] [Accepted: 07/27/2017] [Indexed: 12/14/2022] Open
Abstract
Variation in social behavior is common yet our knowledge of the mechanisms underpinning its evolution is limited. The fire ant Solenopsis invicta provides a textbook example of a Mendelian element controlling social organization: alternate alleles of a genetic element first identified as encoding an odorant binding protein (OBP) named Gp-9 determine whether a colony accepts one or multiple queens. The potential roles of such a protein in perceiving olfactory cues and evidence of positive selection on its amino acid sequence made it an appealing candidate gene. However, we recently showed that recombination is suppressed between Gp-9 and hundreds of other genes as part of a >19 Mb supergene-like region carried by a pair of social chromosomes. This finding raises the need to reassess the potential role of Gp-9. We identify 23 OBPs in the fire ant genome assembly, including nine located in the region of suppressed recombination with Gp-9. For six of these, the alleles carried by the two variants of the supergene-like region differ in protein-coding sequence and thus likely in function, with Gp-9 showing the strongest evidence of positive selection. We identify an additional OBP specific to the Sb variant of the region. Finally, we find that 14 OBPs are differentially expressed between single- and multiple-queen colonies. These results are consistent with multiple OBPs playing a role in determining social structure.
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Affiliation(s)
- Rodrigo Pracana
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
| | - Ilya Levantis
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
| | - Carlos Martínez‐Ruiz
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
| | - Eckart Stolle
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
| | - Anurag Priyam
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
| | - Yannick Wurm
- School of Biological and Chemical SciencesQueen Mary University of LondonE1 4NSLondonUnited Kingdom
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42
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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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43
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Boomsma JJ, Gawne R. Superorganismality and caste differentiation as points of no return: how the major evolutionary transitions were lost in translation. Biol Rev Camb Philos Soc 2017; 93:28-54. [PMID: 28508537 DOI: 10.1111/brv.12330] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 03/04/2017] [Accepted: 03/08/2017] [Indexed: 12/27/2022]
Abstract
More than a century ago, William Morton Wheeler proposed that social insect colonies can be regarded as superorganisms when they have morphologically differentiated reproductive and nursing castes that are analogous to the metazoan germ-line and soma. Following the rise of sociobiology in the 1970s, Wheeler's insights were largely neglected, and we were left with multiple new superorganism concepts that are mutually inconsistent and uninformative on how superorganismality originated. These difficulties can be traced to the broadened sociobiological concept of eusociality, which denies that physical queen-worker caste differentiation is a universal hallmark of superorganismal colonies. Unlike early evolutionary naturalists and geneticists such as Weismann, Huxley, Fisher and Haldane, who set out to explain the acquisition of an unmated worker caste, the goal of sociobiology was to understand the evolution of eusociality, a broad-brush convenience category that covers most forms of cooperative breeding. By lumping a diverse spectrum of social systems into a single category, and drawing attention away from the evolution of distinct quantifiable traits, the sociobiological tradition has impeded straightforward connections between inclusive fitness theory and the major evolutionary transitions paradigm for understanding irreversible shifts to higher organizational complexity. We evaluate the history by which these inconsistencies accumulated, develop a common-cause approach for understanding the origins of all major transitions in eukaryote hierarchical complexity, and use Hamilton's rule to argue that they are directly comparable. We show that only Wheeler's original definition of superorganismality can be unambiguously linked to irreversible evolutionary transitions from context-dependent reproductive altruism to unconditional differentiation of permanently unmated castes in the ants, corbiculate bees, vespine wasps and higher termites. We argue that strictly monogamous parents were a necessary, albeit not sufficient condition for all transitions to superorganismality, analogous to single-zygote bottlenecking being a necessary but not sufficient condition for the convergent origins of complex soma across multicellular eukaryotes. We infer that conflict reduction was not a necessary condition for the origin of any of these major transitions, and conclude that controversies over the status of inclusive fitness theory primarily emanate from the arbitrarily defined sociobiological concepts of superorganismality and eusociality, not from the theory itself.
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Affiliation(s)
- Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.,Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
| | - Richard Gawne
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.,Department of Biology, Duke University, 130 Science Drive, Durham, NC, 27708, USA
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Avalos A, Pérez E, Vallejo L, Pérez ME, Abramson CI, Giray T. Social signals and aversive learning in honey bee drones and workers. Biol Open 2017; 6:41-49. [PMID: 27895050 PMCID: PMC5278427 DOI: 10.1242/bio.021543] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The dissemination of information is a basic element of group cohesion. In honey bees (Apis mellifera Linnaeus 1758), like in other social insects, the principal method for colony-wide information exchange is communication via pheromones. This medium of communication allows multiple individuals to conduct tasks critical to colony survival. Social signaling also establishes conflict at the level of the individual who must trade-off between attending to the immediate environment or the social demand. In this study we examined this conflict by challenging highly social worker honey bees, and less social male drone honey bees undergoing aversive training by presenting them with a social stress signal (isopentyl acetate, IPA). We utilized IPA exposure methods that caused lower learning performance in appetitive learning in workers. Exposure to isopentyl acetate (IPA) did not affect performance of drones and had a dose-specific effect on worker response, with positive effects diminishing at higher IPA doses. The IPA effects are specific because non-social cues, such as the odor cineole, improve learning performance in drones, and social homing signals (geraniol) did not have a discernible effect on drone or worker performance. We conclude that social signals do generate conflict and that response to them is dependent on signal relevance to the individual as well as the context. We discuss the effect of social signal on learning both related to its social role and potential evolutionary history.
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Affiliation(s)
- Arian Avalos
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Eddie Pérez
- Department of Biology, University of Puerto Rico, San Juan, PR 00931, USA
| | - Lianna Vallejo
- Department of Biology, University of Puerto Rico, San Juan, PR 00931, USA
| | - María E Pérez
- Department of Mathematics, University of Puerto Rico, San Juan, PR 00931, USA
| | - Charles I Abramson
- Department of Psychology, Oklahoma State University, Stillwater, OK 74074, USA
| | - Tugrul Giray
- Department of Biology, University of Puerto Rico, San Juan, PR 00931, USA
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Helmkampf M, Mikheyev AS, Kang Y, Fewell J, Gadau J. Gene expression and variation in social aggression by queens of the harvester ant Pogonomyrmex californicus. Mol Ecol 2016; 25:3716-30. [PMID: 27178446 DOI: 10.1111/mec.13700] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 04/14/2016] [Accepted: 05/02/2016] [Indexed: 02/03/2023]
Abstract
A key requirement for social cooperation is the mitigation and/or social regulation of aggression towards other group members. Populations of the harvester ant Pogonomyrmex californicus show the alternate social phenotypes of queens founding nests alone (haplometrosis) or in groups of unrelated yet cooperative individuals (pleometrosis). Pleometrotic queens display an associated reduction in aggression. To understand the proximate drivers behind this variation, we placed foundresses of the two populations into social environments with queens from the same or the alternate population, and measured their behaviour and head gene expression profiles. A proportion of queens from both populations behaved aggressively, but haplometrotic queens were significantly more likely to perform aggressive acts, and conflict escalated more frequently in pairs of haplometrotic queens. Whole-head RNA sequencing revealed variation in gene expression patterns, with the two populations showing moderate differentiation in overall transcriptional profile, suggesting that genetic differences underlie the two founding strategies. The largest detected difference, however, was associated with aggression, regardless of queen founding type. Several modules of coregulated genes, involved in metabolism, immune system and neuronal function, were found to be upregulated in highly aggressive queens. Conversely, nonaggressive queens exhibited a striking pattern of upregulation in chemosensory genes. Our results highlight that the social phenotypes of cooperative vs. solitary nest founding tap into a set of gene regulatory networks that seem to govern aggression level. We also present a number of highly connected hub genes associated with aggression, providing opportunity to further study the genetic underpinnings of social conflict and tolerance.
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Affiliation(s)
- Martin Helmkampf
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ, 85287, USA
| | - Alexander S Mikheyev
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, 904-0495, Japan
| | - Yun Kang
- College of Letters and Sciences, Arizona State University, 7001 E. Williams Field Road, Mesa, AZ, 85212, USA
| | - Jennifer Fewell
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ, 85287, USA
| | - Jürgen Gadau
- School of Life Sciences, Arizona State University, 427 East Tyler Mall, Tempe, AZ, 85287, USA
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Howe J, Schiøtt M, Boomsma JJ. Tachykinin Expression Levels Correlate with Caste-Specific Aggression in Workers of the Leaf-Cutting Ant Acromyrmex echinatior. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Camiletti AL, Thompson GJ. Drosophila As a Genetically Tractable Model for Social Insect Behavior. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
Many exciting studies have begun to elucidate the genetics of the morphological and physiological diversity of ants, but as yet few studies have investigated the genetics of ant behavior directly. Ant genomes are marked by extreme rates of gene turnover, especially in gene families related to olfactory communication, such as the synthesis of cuticular hydrocarbons and the perception of environmental semiochemicals. Transcriptomic and epigenetic differences are apparent between reproductive and sterile females, males and females, and workers that differ in body size. Quantitative genetic approaches suggest heritability of task performance, and population genetic studies indicate a genetic association with reproductive status in some species. Gene expression is associated with behavior including foraging, response to queens attempting to join a colony, circadian patterns of task performance, and age-related changes of task. Ant behavioral genetics needs further investigation of the feedback between individual-level physiological changes and socially mediated responses to environmental conditions.
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Affiliation(s)
- D A Friedman
- Department of Biology, Stanford University, Stanford, California 94305-5020;
| | - D M Gordon
- Department of Biology, Stanford University, Stanford, California 94305-5020;
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50
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Complex patterns of differential expression in candidate master regulatory genes for social behavior in honey bees. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2071-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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