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Chen J, Guan Z, Sun L, Fan X, Wang D, Yu X, Lyu L, Qi G. N 6-methyladenosine modification of RNA controls dopamine synthesis to influence labour division in ants. Mol Ecol 2024; 33:e17322. [PMID: 38501589 DOI: 10.1111/mec.17322] [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: 10/16/2023] [Revised: 03/03/2024] [Accepted: 03/06/2024] [Indexed: 03/20/2024]
Abstract
The N6-methyladenosine (m6A) modification of RNA has been reported to remodel gene expression in response to environmental conditions; however, the biological role of m6A in social insects remains largely unknown. In this study, we explored the role of m6A in the division of labour by worker ants (Solenopsis invicta). We first determined the presence of m6A in RNAs from the brains of worker ants and found that m6A methylation dynamics differed between foragers and nurses. Depletion of m6A methyltransferase or chemical suppression of m6A methylation in foragers resulted in a shift to 'nurse-like' behaviours. Specifically, mRNAs of dopamine receptor 1 (Dop1) and dopamine transporter (DAT) were modified by m6A, and their expression increased dopamine levels to promote the behavioural transition from foragers to nurses. The abundance of Dop1 and DAT mRNAs and their stability were reduced by the inhibition of m6A modification caused by the silencing of Mettl3, suggesting that m6A modification in worker ants modulates dopamine synthesis, which regulates labour division. Collectively, our results provide the first example of the epitranscriptomic regulation of labour division in social insects and implicate m6A regulatory mechanism as a potential novel target for controlling red imported fire ants.
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Affiliation(s)
- Jie Chen
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
| | - Ziying Guan
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
| | - Lina Sun
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xinlin Fan
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Desen Wang
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, Guangdong, China
| | - Xiaoqiang Yu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Lihua Lyu
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
| | - Guojun Qi
- Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, Guangdong, China
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2
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Chen J, Ma Y, Guan Z, Liu Q, Shi Q, Qi G, Chen T, Lyu L. Labor division of worker ants can be controlled by insulin synthesis targeted through miR-279c-5p in Solenopsis invicta (Hymenoptera: Formicidae). PEST MANAGEMENT SCIENCE 2023; 79:5029-5043. [PMID: 37552557 DOI: 10.1002/ps.7704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/24/2023] [Accepted: 08/08/2023] [Indexed: 08/10/2023]
Abstract
BACKGROUND In social insects, the labor division of workers is ubiquitous and controlled by genetic and environmental factors. However, how they modulate this coordinately remains poorly understood. RESULTS We report miR-279c-5p participation in insulin synthesis and behavioral transition by negatively regulating Rab8A in Solenopsis invicta. Eusocial specific miR-279c-5p is age-associated and highly expressed in nurse workers, and localized in the cytoplasm of neurons, where it is partly co-localized with its target, Rab8A. We determined that miR-279c-5p agomir suppressed Rab8A expression in forager workers, consequently decreasing insulin content, resulting in the behavioral shift to 'nurse-like' behaviors, while the decrease in miR-279c-5p increased Rab8A expression and increased insulin content in nurse workers, leading to the behavioral shift to 'foraging-like' behaviors. Moreover, insulin could rescue the 'foraging behavior' induced by feeding miR-279c-5p to nurse workers. The overexpression and suppression of miR-279c-5p in vivo caused an obvious behavioral transition between foragers and nurses, and insulin synthesis was affected by miR-279c-5p by regulating the direct target Rab8A. CONCLUSION We first report that miR-279c-5p is a novel regulator that promotes labor division by negatively regulating the target gene Rab8A by controlling insulin production in ants. This miRNA-mediated mechanism is significant for understanding the behavioral plasticity of social insects between complex factors and potentially provides new targets for controlling red imported fire ants. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jie Chen
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Yunjie Ma
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Ziying Guan
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Qin Liu
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Qingxing Shi
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Guojun Qi
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Ting Chen
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Lihua Lyu
- Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
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3
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Das B, Gordon DM. Biological rhythms and task allocation in ant colonies. CURRENT OPINION IN INSECT SCIENCE 2023:101062. [PMID: 37247773 DOI: 10.1016/j.cois.2023.101062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/15/2023] [Accepted: 05/23/2023] [Indexed: 05/31/2023]
Abstract
Task allocation in ant colonies, mediated by social interactions, regulates which individuals perform each task, and when they are active, in response to the current situation. Many tasks are performed in a daily temporal pattern. An ant's biological clock depends on patterns of gene expression that are regulated using a negative feedback loop which is synchronized to earth's rotation by external cues. An individual's biological clock can shift in response to social cues, and this plasticity contributes to task switching. Daily rhythms in individual ant behavior combine, via interactions within and across task groups, to adjust the collective behavior of colonies. Further work is needed to elucidate how the social cues that lead to task switching influence the molecular mechanisms that generate clock outputs associated with each task, and to investigate the evolution of temporal patterns in task allocation in relation to ecological factors.
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4
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Toga K, Bono H. Meta-Analysis of Public RNA Sequencing Data Revealed Potential Key Genes Associated with Reproductive Division of Labor in Social Hymenoptera and Termites. Int J Mol Sci 2023; 24:ijms24098353. [PMID: 37176060 PMCID: PMC10179490 DOI: 10.3390/ijms24098353] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Eusociality in insects has evolved independently many times. One of the most notable characteristics of eusociality is the reproductive division of labor. In social insects, the reproductive division of labor is accomplished by queens and workers. Transcriptome analyses of queens and workers have been conducted for various eusocial species. However, the genes that regulate the reproductive division of labor across all or multiple eusocial species have not yet been fully elucidated. Therefore, we conducted a meta-analysis using publicly available RNA-sequencing data from four major groups of social insects. In this meta-analysis, we collected 258 pairs (queen vs. worker) of RNA-sequencing data from 34 eusocial species. The meta-analysis identified a total of 20 genes that were differentially expressed in queens or workers. Out of these, 12 genes have not previously been reported to be involved in the reproductive division of labor. Functional annotation of these 20 genes in other organisms revealed that they could be regulators of behaviors and physiological states related to the reproductive division of labor. These 20 genes, revealed using massive datasets of numerous eusocial insects, may be key regulators of the reproductive division of labor.
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Affiliation(s)
- Kouhei Toga
- Laboratory of BioDX, PtBio Co-Creation Research Center, Genome Editing Innovation Center, Hiroshima University, 3-10-23 Kagamiyama, Higashi-Hiroshima City 739-0046, Hiroshima, Japan
- Laboratory of Genome Informatics, Graduate School of Integrated Sciences for Life, Hiroshima University, 3-10-23 Kagamiyama, Higashi-Hiroshima City 739-0046, Hiroshima, Japan
| | - Hidemasa Bono
- Laboratory of BioDX, PtBio Co-Creation Research Center, Genome Editing Innovation Center, Hiroshima University, 3-10-23 Kagamiyama, Higashi-Hiroshima City 739-0046, Hiroshima, Japan
- Laboratory of Genome Informatics, Graduate School of Integrated Sciences for Life, Hiroshima University, 3-10-23 Kagamiyama, Higashi-Hiroshima City 739-0046, Hiroshima, Japan
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Anderson C, Fernandez-Nieves A. Social interactions lead to motility-induced phase separation in fire ants. Nat Commun 2022; 13:6710. [PMID: 36344501 PMCID: PMC9640710 DOI: 10.1038/s41467-022-34181-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/13/2022] [Indexed: 11/09/2022] Open
Abstract
Collections of fire ants are a form of active matter, as the ants use their internal metabolism to self-propel. In the absence of aligning interactions, theory and simulations predict that active matter with spatially dependent motility can undergo motility-induced phase separation. However, so far in experiments, the motility effects that drive this process have come from either crowding or an external parameter. Though fire ants are social insects that communicate and cooperate in nontrivial ways, we show that the effect of their interactions can also be understood within the framework of motility-induced phase separation. In this context, the slowing down of ants when they approach each other results in an effective attraction that can lead to space-filling clusters and an eventual formation of dynamical heterogeneities. These results illustrate that motility-induced phase separation can provide a unifying framework to rationalize the behavior of a wide variety of active matter systems.
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Affiliation(s)
- Caleb Anderson
- grid.5841.80000 0004 1937 0247Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain ,grid.213917.f0000 0001 2097 4943School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 USA
| | - Alberto Fernandez-Nieves
- grid.5841.80000 0004 1937 0247Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain ,grid.213917.f0000 0001 2097 4943School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 USA ,grid.425902.80000 0000 9601 989XICREA-Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain ,grid.5841.80000 0004 1937 0247Institute for Complex Systems (UBICS), University of Barcelona, 08028 Barcelona, Spain
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6
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Das B, de Bekker C. Time-course RNASeq of Camponotus floridanus forager and nurse ant brains indicate links between plasticity in the biological clock and behavioral division of labor. BMC Genomics 2022; 23:57. [PMID: 35033027 PMCID: PMC8760764 DOI: 10.1186/s12864-021-08282-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/24/2021] [Indexed: 12/19/2022] Open
Abstract
Background Circadian clocks allow organisms to anticipate daily fluctuations in their environment by driving rhythms in physiology and behavior. Inter-organismal differences in daily rhythms, called chronotypes, exist and can shift with age. In ants, age, caste-related behavior and chronotype appear to be linked. Brood-tending nurse ants are usually younger individuals and show “around-the-clock” activity. With age or in the absence of brood, nurses transition into foraging ants that show daily rhythms in activity. Ants can adaptively shift between these behavioral castes and caste-associated chronotypes depending on social context. We investigated how changes in daily gene expression could be contributing to such behavioral plasticity in Camponotus floridanus carpenter ants by combining time-course behavioral assays and RNA-Sequencing of forager and nurse brains. Results We found that nurse brains have three times fewer 24 h oscillating genes than foragers. However, several hundred genes that oscillated every 24 h in forager brains showed robust 8 h oscillations in nurses, including the core clock genes Period and Shaggy. These differentially rhythmic genes consisted of several components of the circadian entrainment and output pathway, including genes said to be involved in regulating insect locomotory behavior. We also found that Vitellogenin, known to regulate division of labor in social insects, showed robust 24 h oscillations in nurse brains but not in foragers. Finally, we found significant overlap between genes differentially expressed between the two ant castes and genes that show ultradian rhythms in daily expression. Conclusion This study provides a first look at the chronobiological differences in gene expression between forager and nurse ant brains. This endeavor allowed us to identify a putative molecular mechanism underlying plastic timekeeping: several components of the ant circadian clock and its output can seemingly oscillate at different harmonics of the circadian rhythm. We propose that such chronobiological plasticity has evolved to allow for distinct regulatory networks that underlie behavioral castes, while supporting swift caste transitions in response to colony demands. Behavioral division of labor is common among social insects. The links between chronobiological and behavioral plasticity that we found in C. floridanus, thus, likely represent a more general phenomenon that warrants further investigation. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08282-x.
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Affiliation(s)
- Biplabendu Das
- Department of Biology, College of Sciences, University of Central Florida, Orlando, FL, 32816, USA. .,Genomics and Bioinformatics Cluster, University of Central Florida, Orlando, FL, 32816, USA.
| | - Charissa de Bekker
- Department of Biology, College of Sciences, University of Central Florida, Orlando, FL, 32816, USA. .,Genomics and Bioinformatics Cluster, University of Central Florida, Orlando, FL, 32816, USA.
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7
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Lucas C, Ben-Shahar Y. The foraging gene as a modulator of division of labour in social insects. J Neurogenet 2021; 35:168-178. [PMID: 34151702 DOI: 10.1080/01677063.2021.1940173] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The social ants, bees, wasps, and termites include some of the most ecologically-successful groups of animal species. Their dominance in most terrestrial environments is attributed to their social lifestyle, which enable their colonies to exploit environmental resources with remarkable efficiency. One key attribute of social insect colonies is the division of labour that emerges among the sterile workers, which represent the majority of colony members. Studies of the mechanisms that drive division of labour systems across diverse social species have provided fundamental insights into the developmental, physiological, molecular, and genomic processes that regulate sociality, and the possible genetic routes that may have led to its evolution from a solitary ancestor. Here we specifically discuss the conserved role of the foraging gene, which encodes a cGMP-dependent protein kinase (PKG). Originally identified as a behaviourally polymorphic gene that drives alternative foraging strategies in the fruit fly Drosophila melanogaster, changes in foraging expression and kinase activity were later shown to play a key role in the division of labour in diverse social insect species as well. In particular, foraging appears to regulate worker transitions between behavioural tasks and specific behavioural traits associated with morphological castes. Although the specific neuroethological role of foraging in the insect brain remains mostly unknown, studies in genetically tractable insect species indicate that PKG signalling plays a conserved role in the neuronal plasticity of sensory, cognitive and motor functions, which underlie behaviours relevant to division of labour, including appetitive learning, aggression, stress response, phototaxis, and the response to pheromones.
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Affiliation(s)
- Christophe Lucas
- Institut de Recherche sur la Biologie de l'Insecte (UMR7261), CNRS - University of Tours, Tours, France
| | - Yehuda Ben-Shahar
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
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8
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Alwash N, Allen AM, B Sokolowski M, Levine JD. The Drosophila melanogaster foraging gene affects social networks. J Neurogenet 2021; 35:249-261. [PMID: 34121597 DOI: 10.1080/01677063.2021.1936517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Drosophila melanogaster displays social behaviors including courtship, mating, aggression, and group foraging. Recent studies employed social network analyses (SNAs) to show that D. melanogaster strains differ in their group behavior, suggesting that genes influence social network phenotypes. Aside from genes associated with sensory function, few studies address the genetic underpinnings of these networks. The foraging gene (for) is a well-established example of a pleiotropic gene that regulates multiple behavioral phenotypes and their plasticity. In D. melanogaster, there are two naturally occurring alleles of for called rover and sitter that differ in their larval and adult food-search behavior as well as other behavioral phenotypes. Here, we hypothesize that for affects behavioral elements required to form social networks and the social networks themselves. These effects are evident when we manipulate gene dosage. We found that flies of the rover and sitter strains exhibit differences in duration, frequency, and reciprocity of pairwise interactions, and they form social networks with differences in assortativity and global efficiency. Consistent with other adult phenotypes influenced by for, rover-sitter heterozygotes show intermediate patterns of dominance in many of these characteristics. Multiple generations of backcrossing a rover allele into a sitter strain showed that many but not all of these rover-sitter differences may be attributed to allelic variation at for. Our findings reveal the significant role that for plays in affecting social network properties and their behavioral elements in Drosophila melanogaster.
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Affiliation(s)
- Nawar Alwash
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Aaron M Allen
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Centre for Neural Circuits and Behavior, University of Oxford, Oxford, UK
| | - Marla B Sokolowski
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
| | - Joel D Levine
- Department of Biology, University of Toronto at Mississauga, Mississauga, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.,Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada.,Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, Toronto, Canada
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9
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Vibratory behaviour produces different vibrations patterns in presence of reproductives in a subterranean termite species. Sci Rep 2021; 11:9902. [PMID: 33972576 PMCID: PMC8110524 DOI: 10.1038/s41598-021-88292-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 03/26/2021] [Indexed: 11/09/2022] Open
Abstract
Vibratory behaviours are widespread in social insects, but the produced vibrations remain poorly explored. Communication using vibrations is an efficient way to transmit information in subterranean environments where visual and odorant signals are less efficient. In termites, different vibratory behaviours are performed in different contexts like reproductive regulation and alarm signalling, but only few studies explored the structure of the produced vibrations (i.e., duration, number of pulses, amplitude). Here, we described several types of vibrations produced by a vibratory behaviour widespread in termites (body-shaking), which can be transmitted through the substrate and detected by other colony members. We analysed the structures of the emitted vibrations and the occurrence of the body-shaking events in presence/absence of reproductives and/or in presence/absence of a stress stimuli (flashlight) in the subterranean termite Reticulitermes flavipes. Interestingly, only the presence of the reproductives did influence the number of pulses and the duration of the emitted vibrations. Moreover, the first part of the emitted vibrations seems to be enough to encode reproductive information, but other parts might hold other type of information. Body-shaking occurrence did increase in presence of reproductives but only briefly under a flashlight. These results show that vibratory cues are complex in termites and their diversity might encode a plurality of social cues.
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10
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Ge J, Ge Z, Zhu D, Wang X. Pheromonal Regulation of the Reproductive Division of Labor in Social Insects. Front Cell Dev Biol 2020; 8:837. [PMID: 32974354 PMCID: PMC7468439 DOI: 10.3389/fcell.2020.00837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/05/2020] [Indexed: 11/13/2022] Open
Abstract
The reproductive altruism in social insects is an evolutionary enigma that has been puzzling scientists starting from Darwin. Unraveling how reproductive skew emerges and maintains is crucial to understand the reproductive altruism involved in the consequent division of labor. The regulation of adult worker reproduction involves conspecific inhibitory signals, which are thought to be chemical signals by numerous studies. Despite the primary identification of few chemical ligands, the action modes of primer pheromones that regulate reproduction and their molecular causes and effects remain challenging. Here, these questions were elucidated by comprehensively reviewing recent advances. The coordination with other modalities of queen pheromones (QPs) and its context-dependent manner to suppress worker reproduction were discussed under the vast variation and plasticity of reproduction during colony development and across taxa. In addition to the effect of QPs, special attention was paid to recent studies revealing the regulatory effect of brood pheromones. Considering the correlation between pheromone and hormone, this study focused on the production and perception of pheromones under the endocrine control and highlighted the pivotal roles of nutrition-related pathways. The novel chemicals and gene pathways discovered by recent works provide new insights into the understanding of social regulation of reproductive division of labor in insects.
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Affiliation(s)
- Jin Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Zhuxi Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Dan Zhu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Xianhui Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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11
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Ruhland F, Moulin M, Choppin M, Meunier J, Lucas C. Reproductives and eggs trigger worker vibration in a subterranean termite. Ecol Evol 2020; 10:5892-5898. [PMID: 32607198 PMCID: PMC7319145 DOI: 10.1002/ece3.6325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/26/2020] [Accepted: 04/07/2020] [Indexed: 01/04/2023] Open
Abstract
In insect societies, the presence of reproductives or eggs has been shown to shape several biological traits in the colony members. Social interactions are one of these traits that involve modification of the communication system of the entire colony. Many studies described the role of chemical compounds and dominance behaviors in the presence of reproductive but vibratory behaviors received very few investigations. Yet, vibratory behaviors are ideal candidates, particularly for subterranean species like termites, as they could be quickly transmitted through the substrate and could be very diversified (origin, modulation). Here, we investigated whether the presence of reproductives/eggs affects the vibratory behavior (body-shaking) of workers in the subterranean termite Reticulitermes flavipes. Our results reveal that the presence of reproductives or eggs triggers an increase of workers' body-shaking, independent of their colony of origin after 24 hr. We hypothesize that vibratory communication could be used to transfer information about the presence of reproductives and eggs to the entire colony, suggesting that vibratory behaviors could serve as an important yet neglected mediator of social regulation.
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Affiliation(s)
- Fanny Ruhland
- Institut de Recherche sur la Biologie de l’Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Marion Moulin
- Institut de Recherche sur la Biologie de l’Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Marina Choppin
- Institut de Recherche sur la Biologie de l’Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Joël Meunier
- Institut de Recherche sur la Biologie de l’Insecte (UMR7261)CNRS – University of ToursToursFrance
| | - Christophe Lucas
- Institut de Recherche sur la Biologie de l’Insecte (UMR7261)CNRS – University of ToursToursFrance
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12
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Hefetz A. The critical role of primer pheromones in maintaining insect sociality. ACTA ACUST UNITED AC 2020; 74:221-231. [PMID: 30920959 DOI: 10.1515/znc-2018-0224] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 03/02/2019] [Indexed: 11/15/2022]
Abstract
Primer pheromones play a pivotal role in the biology and social organization of insect societies. Despite their importance, they have been less studied because of the complexity of the required bioassays and, consequently, only a few of them have been chemically identified to date. The major primer pheromones are that of the queen pheromones that regulate reproductive skew and maintain colony cohesion and function. From a theoretical viewpoint, several features regarding the chemistry of queen pheromones can be predicted. They should be generally nonvolatile in order to avoid saturation of the colony space, which might otherwise hamper their perception because of sensory habituation. Accordingly, they should be actively dispersed throughout the colony by workers. The queen pheromone should also be caste-specific, qualitatively different from any worker pheromone, and preferably multicomponent, to allow unequivocal identification of the queen. The bi-potency of the female larvae in social Hymenoptera to become queen or worker necessitates strict regulation over pheromone production. Indeed, in the honeybee, the biosynthetic pathways as well as the genomic expressions are completely disparate between queens and workers. Future advances in chemical analyses, transcriptomics, proteomics, and metabolomics will enrich our understanding of the chemistry, mechanisms, and crucial role that primer pheromones play in social evolution.
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Affiliation(s)
- Abraham Hefetz
- Tel Aviv University, Department of Zoology, Tel Aviv, Israel.,Ruppin Academic Center, School of Marine Sciences, Michmoret, Israel
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13
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Yan Z, Martin SH, Gotzek D, Arsenault SV, Duchen P, Helleu Q, Riba-Grognuz O, Hunt BG, Salamin N, Shoemaker D, Ross KG, Keller L. Evolution of a supergene that regulates a trans-species social polymorphism. Nat Ecol Evol 2020; 4:240-249. [PMID: 31959939 DOI: 10.1038/s41559-019-1081-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/04/2019] [Indexed: 11/09/2022]
Abstract
Supergenes are clusters of linked genetic loci that jointly affect the expression of complex phenotypes, such as social organization. Little is known about the origin and evolution of these intriguing genomic elements. Here we analyse whole-genome sequences of males from native populations of six fire ant species and show that variation in social organization is under the control of a novel supergene haplotype (termed Sb), which evolved by sequential incorporation of three inversions spanning half of a 'social chromosome'. Two of the inversions interrupt protein-coding genes, resulting in the increased expression of one gene and modest truncation in the primary protein structure of another. All six socially polymorphic species studied harbour the same three inversions, with the single origin of the supergene in their common ancestor inferred by phylogenomic analyses to have occurred half a million years ago. The persistence of Sb along with the ancestral SB haplotype through multiple speciation events provides a striking example of a functionally important trans-species social polymorphism presumably maintained by balancing selection. We found that while recombination between the Sb and SB haplotypes is severely restricted in all species, a low level of gene flux between the haplotypes has occurred following the appearance of the inversions, potentially mitigating the evolutionary degeneration expected at genomic regions that cannot freely recombine. These results provide a detailed picture of the structural genomic innovations involved in the formation of a supergene controlling a complex social phenotype.
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Affiliation(s)
- Zheng Yan
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Simon H Martin
- Institute of Evolutionary Biology, the University of Edinburgh, Edinburgh, UK
| | - Dietrich Gotzek
- Department of Entomology and Laboratories of Analytical Biology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | | | - Pablo Duchen
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
| | - Quentin Helleu
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Oksana Riba-Grognuz
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Brendan G Hunt
- Department of Entomology, University of Georgia, Athens, GA, USA
| | - Nicolas Salamin
- Department of Computational Biology, University of Lausanne, Lausanne, Switzerland
| | - DeWayne Shoemaker
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, USA
| | - Kenneth G Ross
- Department of Entomology, University of Georgia, Athens, GA, USA.
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
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14
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Steffen MA, Rehan SM. Genetic signatures of dominance hierarchies reveal conserved cis-regulatory and brain gene expression underlying aggression in a facultatively social bee. GENES BRAIN AND BEHAVIOR 2019; 19:e12597. [PMID: 31264771 DOI: 10.1111/gbb.12597] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 11/29/2022]
Abstract
Agonistic interactions among individuals can result in the formation of dominance hierarches that can reinforce individual behavior and social status. Such dominance hierarches precede the establishment of reproductive dominance, division of labor and caste formation in highly social insect taxa. As such, deciphering the molecular basis of aggression is fundamental in understanding the mechanisms of social evolution. Assessing the proximate mechanisms of aggression in incipiently social bees can provide insights into the foundations of genomic mechanisms of social behavior. Here, we measured the effects of aggression on brain gene expression in the incipiently social bee, Ceratina australensis. We examine the brain transcriptomic differences between individuals who have experienced recurrent winning, losing, or a change in rank during repeated encounters. Using comparative analyses across taxa, we identify deeply conserved candidate genes, pathways, and regulatory networks for the formation of social hierarchies.
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Affiliation(s)
- Michael A Steffen
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire
| | - Sandra M Rehan
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire
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15
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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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16
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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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17
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Kohlmeier P, Alleman AR, Libbrecht R, Foitzik S, Feldmeyer B. Gene expression is more strongly associated with behavioural specialization than with age or fertility in ant workers. Mol Ecol 2019; 28:658-670. [PMID: 30525254 DOI: 10.1111/mec.14971] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 11/09/2018] [Accepted: 11/15/2018] [Indexed: 12/19/2022]
Abstract
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialization from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3,644 genes were associated with behavioural specialization which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characterized by an upregulation of three Vitellogenin (Vg) genes, one of which, Vg-like A, was the most differentially expressed gene that was recently shown experimentally to control the switch from brood to worker care. The expression of Conventional Vg was unlinked to behavioural specialization, age or fertility, which contrasts to studies on bees and some ants. Diversity in Vg/Vg-like copy number and expression bias across ants supports subfunctionalization of Vg genes and indicates that some regulatory mechanisms of division of labour diverged in different ant lineages. Simulations revealed that our experimental dissociation of co-varying factors reduced transcriptomic noise, suggesting that confounding factors could potentially explain inconsistencies across transcriptomic studies of behavioural specialization in ants. Thus, our study reveals that worker gene expression is mainly linked to the worker's function for the colony and provides novel insights into the evolution of sociality in ants.
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Affiliation(s)
- Philip Kohlmeier
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Austin R Alleman
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Romain Libbrecht
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
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18
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Allen ML, Rhoades JH, Sparks ME, Grodowitz MJ. Differential Gene Expression in Red Imported Fire Ant ( Solenopsis invicta) (Hymenoptera: Formicidae) Larval and Pupal Stages. INSECTS 2018; 9:E185. [PMID: 30563147 PMCID: PMC6315859 DOI: 10.3390/insects9040185] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/27/2018] [Accepted: 11/29/2018] [Indexed: 12/11/2022]
Abstract
Solenopsis invicta Buren is an invasive ant species that has been introduced to multiple continents. One such area, the southern United States, has a history of multiple control projects using chemical pesticides over varying ranges, often resulting in non-target effects across trophic levels. With the advent of next generation sequencing and RNAi technology, novel investigations and new control methods are possible. A robust genome-guided transcriptome assembly was used to investigate gene expression differences between S. invicta larvae and pupae. These life stages differ in many physiological processes; of special importance is the vital role of S. invicta larvae as the colonies' "communal gut". Differentially expressed transcripts were identified related to many important physiological processes, including digestion, development, cell regulation and hormone signaling. This dataset provides essential developmental knowledge that reveals the dramatic changes in gene expression associated with social insect life stage roles, and can be leveraged using RNAi to develop effective control methods.
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Affiliation(s)
- Margaret L Allen
- USDA-ARS Biological Control of Pests Research Unit, National Biological Control Laboratory, Stoneville, MS 38776, USA.
| | - Joshua H Rhoades
- USDA-ARS Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD 20705, USA.
| | - Michael E Sparks
- USDA-ARS Invasive Insect Biocontrol and Behavior Laboratory, Beltsville, MD 20705, USA.
| | - Michael J Grodowitz
- USDA-ARS Biological Control of Pests Research Unit, National Biological Control Laboratory, Stoneville, MS 38776, USA.
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19
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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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20
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Hsu HW, Chiu MC, Shoemaker D, Yang CCS. Viral infections in fire ants lead to reduced foraging activity and dietary changes. Sci Rep 2018; 8:13498. [PMID: 30202033 PMCID: PMC6131164 DOI: 10.1038/s41598-018-31969-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 08/30/2018] [Indexed: 12/28/2022] Open
Abstract
Despite the presence of conserved innate immune function, many insects have evolved a variety of mechanical, chemical, and behavioral defensive responses to pathogens. Illness-induced anorexia and dietary changes are two behavioral defensive strategies found in some solitary insects, but little is known regarding the role of such behaviors in social insects, especially in ants. In the present study we examined if such reduced foraging activity exists for a social insect, the invasive fire ant Solenopsis invicta, and its viral pathogen, Solenopsis invicta virus 1 (SINV-1). Virus-free fire ant colonies were split into two colony fragments, one of which subsequently was inoculated with SINV-1. Four food resources with different macronutrient ratios were presented to both colony fragments. SINV-1-inoculated colony fragments consistently displayed reduced foraging performance (e.g., foraging intensity and recruitment efficiency), a decline in lipid intake, and a shift in dietary preference to carbohydrate-rich foods compared with virus-free fragments. These findings provide the first evidence for virus-induced behavioral responses and dietary shifts in shaping the host-pathogen interactions in fire ants. The findings also suggest a possible mechanism for how fire ant colonies respond to viral epidemics. Potential implications of these behavioral differences for current management strategies are discussed.
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Affiliation(s)
- Hung-Wei Hsu
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwakecho, Kyoto, 606-8502, Japan.,Department of Entomology, National Taiwan University, Taipei, 106, Taiwan
| | - Ming-Chung Chiu
- Department of Entomology, National Taiwan University, Taipei, 106, Taiwan.,Department of Biological Resources, National Chiayi University, Chiayi, 600, Taiwan
| | - DeWayne Shoemaker
- Department of Entomology & Plant Pathology, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Chin-Cheng Scotty Yang
- Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
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21
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Queen Control or Queen Signal in Ants: What Remains of the Controversy 25 Years After Keller and Nonacs' Seminal Paper? J Chem Ecol 2018; 44:805-817. [PMID: 29858748 DOI: 10.1007/s10886-018-0974-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/05/2018] [Accepted: 05/25/2018] [Indexed: 10/14/2022]
Abstract
Ant queen pheromones (QPs) have long been known to affect colony functioning. In many species, QPs affect important reproductive functions such as diploid larvae sexualization and egg-laying by workers, unmated queens (gynes), or other queens. Until the 1990s, these effects were generally viewed to be the result of queen manipulation through the use of coercive or dishonest signals. However, in their seminal 1993 paper, Keller and Nonacs challenged this idea, suggesting that QPs had evolved as honest signals that informed workers and other colony members of the queen's presence and reproductive state. This paper has greatly influenced the study of ant QPs and inspired numerous attempts to identify fertility-related compounds and test their physiological and behavioral effects. In the present article, we review the literature on ant QPs in various contexts and pay special attention to the role of cuticular hydrocarbons (CHCs). Although the controversy generated by Keller and Nonacs' (Anim Behav 45:787-794, 1993) paper is currently less intensively debated, there is still no clear evidence which allows the rejection of the queen control hypothesis in favor of the queen signal hypothesis. We argue that important questions remain regarding the mode of action of QPs, and their targets which may help understanding their evolution.
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22
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Kohlmeier P, Feldmeyer B, Foitzik S. Vitellogenin-like A-associated shifts in social cue responsiveness regulate behavioral task specialization in an ant. PLoS Biol 2018; 16:e2005747. [PMID: 29874231 PMCID: PMC5991380 DOI: 10.1371/journal.pbio.2005747] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/03/2018] [Indexed: 11/22/2022] Open
Abstract
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Secondly, an experimental knockdown of Vg-like A in the fat body caused a reduction in brood care and an increase in nestmate care in young ant workers. Nestmate care is normally exhibited by older workers. We demonstrate experimentally that this task switch is at least partly based on Vg-like A-associated shifts in responsiveness from brood to worker cues. We thus reveal a novel mechanism leading to early behavioral maturation via changes in social cue responsiveness mediated by Vg-like A and associated pathways, which proximately play a role in regulating division of labor.
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Affiliation(s)
- Philip Kohlmeier
- Institute of Organismic and Molecular and Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular and Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
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23
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Qi YX, Zeng T, Wang L, Lu YY. Biogenic amine signaling systems in the red imported fire ant, Solenopsis invicta - Possible contributors to worker division of labor. Gen Comp Endocrinol 2018. [PMID: 29526717 DOI: 10.1016/j.ygcen.2018.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The red imported fire ant, Solenopsis invicta Buren, is a dangerous invasive pest in the United States, China and other countries. Efficient division of labor is one of the main reasons for the success of this social insect. Biogenic amines are important regulators of worker division of labor in this eusocial insect, but the related molecular mechanisms are largely unknown. In this study, we identified 10 candidate biogenic amine synthetic enzyme genes and 17 candidate biogenic amine receptor genes in the genome of S. invicta. Quantitative real-time PCR results indicated that foragers had higher head transcripts levels of all the tested enzyme genes than nurses did. In the abdomen, only the rate-limiting enzyme genes for the biosynthesis of serotonin and dopamine were higher in foragers than in nurses. Among the tested serotonin receptors, only the expression of 5-HT2A gene showed significant difference between foragers and nurses. In the head, more abundant 5-HT2A transcripts were detected in foragers than in nurses. Foragers expressed higher Octβ4R than nurses in the head and abdomen. However, much lower mRNA levels of Dop3 receptor gene were detected in both body regions of foragers than nurses. Several other octopamine and tyramine receptor genes were also differentially expressed between foragers and nurses in the head and/or in the abdomen. Our results will improve the understanding of molecular mechanisms underlying biogenic amine modulation of the worker division of labor in S. invicta.
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Affiliation(s)
- Yi-Xiang Qi
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China.
| | - Tian Zeng
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Lei Wang
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Yong-Yue Lu
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, China.
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24
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Manfredini F, Brown MJF, Toth AL. Candidate genes for cooperation and aggression in the social wasp Polistes dominula. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:449-463. [PMID: 29488013 PMCID: PMC5907630 DOI: 10.1007/s00359-018-1252-6] [Citation(s) in RCA: 14] [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: 12/04/2017] [Revised: 02/09/2018] [Accepted: 02/10/2018] [Indexed: 11/28/2022]
Abstract
Cooperation and aggression are ubiquitous in social groups, and the genetic mechanisms underlying these behaviours are of great interest for understanding how social group formation is regulated and how it evolves. In this study, we used a candidate gene approach to investigate the patterns of expression of key genes for cooperation and aggression in the brain of a primitively eusocial wasp, Polistes dominula, during colony founding, when multiple foundresses can join the same nest and establish subtle hierarchies of dominance. We used a comparative approach to select candidate genes for cooperation and aggression looking at two previously published studies on global gene expression in wasps and ants. We tested the expression of these genes in P. dominula wasps that were either displaying aggressive behaviour (dominant and single foundresses) or cooperation (subordinate foundresses and workers) towards nestmates. One gene in particular, the egg yolk protein vitellogenin, known for its reproductive role in insects, displayed patterns of expression that strongly matched wasp social rank. We characterize the genomic context of vitellogenin by building a head co-expression gene network for P. dominula, and we discuss a potential role for vitellogenin as a mediator of social interactions in wasps.
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Affiliation(s)
- Fabio Manfredini
- School of Biological Sciences, Royal Holloway University of London, Egham, UK.
| | - Mark J F Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Amy L Toth
- Departments of Ecology, Evolution, and Organismal Biology and Entomology, Iowa State University, Ames, IA, USA
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25
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Epigenetic switch turns on genetic behavioral variations. Proc Natl Acad Sci U S A 2017; 114:12365-12367. [PMID: 29114044 DOI: 10.1073/pnas.1717376114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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26
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Qiu HL, Zhao CY, He YR. On the Molecular Basis of Division of Labor in Solenopsis invicta (Hymenoptera: Formicidae) Workers: RNA-seq Analysis. JOURNAL OF INSECT SCIENCE (ONLINE) 2017; 17:3093133. [PMID: 28365770 PMCID: PMC5469383 DOI: 10.1093/jisesa/iex002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Indexed: 06/07/2023]
Abstract
The fire ant Solenopsis invicta Buren is an important invasive pest. Among S. invicta workers behavioral changes depend on age where younger ants are nurses and older ants foragers. To identify potential genes associated with this division of labor, we compared gene expression between foragers and nurses by high-throughput sequencing. In total, we identified 1,618 genes significantly differently expressed between nurses and foragers, of which 542 were upregulated in foragers and 1,076 were upregulated in nurses. Several pathways related to metabolism were significantly enriched, such as lipid storage and fatty acid biosynthesis, which might contribute to the division of labor in S. invicta. Several genes involved in DNA methylation, transcription, and olfactory responses as well as resistance to stress were differentially expressed between nurses and foragers workers. Finally, a comparison between previously published microarray data and our RNA-seq data in S. invicta shows 116 genes overlap, and the GO term myofibril assembly (GO: 0030239) were simultaneously significantly enriched. These results advance knowledge of potentially important genes and molecular pathways associated with worker division of labor in S. invicta. We hope our dataset will provide . candidate target genes to disrupt organization in S. invicta as a control strategy against this invasive pest.
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Affiliation(s)
- Hua-Long Qiu
- Department of Entomology College of Agriculture, South China Agricultural University, Guangdong, Guangzhou 510642, China
| | - Cheng-Yin Zhao
- Department of Life Science Luoyang Normal University, Henan, Luoyang 471000, China
| | - Yu-Rong He
- Department of Entomology College of Agriculture, South China Agricultural University, Guangdong, Guangzhou 510642, China
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27
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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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28
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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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Kapheim KM. Genomic sources of phenotypic novelty in the evolution of eusociality in insects. CURRENT OPINION IN INSECT SCIENCE 2016; 13:24-32. [PMID: 27436550 DOI: 10.1016/j.cois.2015.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/13/2015] [Accepted: 10/28/2015] [Indexed: 06/06/2023]
Abstract
Genomic resources are now available for closely related species that vary in social behavior, providing insight on the genomics of social evolution. Changes in the architecture of gene regulatory networks likely influence the evolutionary trajectory of social traits. Evolutionarily novel genes are likely important in the evolution of social diversity among insects, but it is unclear whether new genes played a driving role in the advent or elaboration of eusociality or if they were instead a result of other genomic features of eusociality. The worker phenotype appears to be the center of genetic novelty, but the mechanisms for this remain unresolved. Future studies are needed to understand how genetic novelty arises, becomes incorporated into existing gene regulatory networks, and the effects this has on the evolution of social traits in closely related social and solitary species.
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Affiliation(s)
- Karen M Kapheim
- Utah State University, Department of Biology, 5305 Old Main Hill, Logan UT 84322, USA.
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Manfredini F, Shoemaker D, Grozinger CM. Dynamic changes in host-virus interactions associated with colony founding and social environment in fire ant queens (Solenopsis invicta). Ecol Evol 2016; 6:233-44. [PMID: 26811788 PMCID: PMC4716520 DOI: 10.1002/ece3.1843] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 11/10/2022] Open
Abstract
The dynamics of host-parasite interactions can change dramatically over the course of a chronic infection as the internal (physiological) and external (environmental) conditions of the host change. When queens of social insects found a colony, they experience changes in both their physiological state (they develop their ovaries and begin laying eggs) and the social environment (they suddenly stop interacting with the other members of the mother colony), making this an excellent model system for examining how these factors interact with chronic infections. We investigated the dynamics of host-viral interactions in queens of Solenopsis invicta (fire ant) as they transition from mating to colony founding/brood rearing to the emergence of the first workers. We examined these dynamics in naturally infected queens in two different social environments, where queens either founded colonies as individuals or as pairs. We hypothesized that stress associated with colony founding plays an important role in the dynamics of host-parasite interactions. We also hypothesized that different viruses have different modalities of interaction with the host that can be quantified by physiological measures and genomic analysis of gene expression in the host. We found that the two most prevalent viruses, SINV-1 and SINV-2, are associated with different fitness costs that are mirrored by different patterns of gene expression in the host. In fact SINV-2, the virus that imposes the significant reduction of a queen's reproductive output is also associated with larger changes of global gene expression in the host. These results show the complexity of interactions between S. invicta and two viral parasites. Our findings also show that chronic infections by viral parasites in insects are dynamic processes that may pose different challenges in the host, laying the groundwork for interesting ecological and evolutionary considerations.
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Affiliation(s)
- Fabio Manfredini
- School of Biological SciencesRoyal Holloway University of LondonEghamUK
- Department of Entomology and Center for Pollinator ResearchThe Pennsylvania State UniversityUniversity ParkPennsylvania
| | | | - Christina M. Grozinger
- Department of Entomology and Center for Pollinator ResearchThe Pennsylvania State UniversityUniversity ParkPennsylvania
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Mooney SJ, Filice DC, Douglas NR, Holmes MM. Task specialization and task switching in eusocial mammals. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.08.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Vojvodic S, Johnson BR, Harpur BA, Kent CF, Zayed A, Anderson KE, Linksvayer TA. The transcriptomic and evolutionary signature of social interactions regulating honey bee caste development. Ecol Evol 2015; 5:4795-807. [PMID: 26640660 PMCID: PMC4662310 DOI: 10.1002/ece3.1720] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/13/2015] [Accepted: 08/19/2015] [Indexed: 11/07/2022] Open
Abstract
The caste fate of developing female honey bee larvae is strictly socially regulated by adult nurse workers. As a result of this social regulation, nurse-expressed genes as well as larval-expressed genes may affect caste expression and evolution. We used a novel transcriptomic approach to identify genes with putative direct and indirect effects on honey bee caste development, and we subsequently studied the relative rates of molecular evolution at these caste-associated genes. We experimentally induced the production of new queens by removing the current colony queen, and we used RNA sequencing to study the gene expression profiles of both developing larvae and their caregiving nurses before and after queen removal. By comparing the gene expression profiles of queen-destined versus worker-destined larvae as well as nurses observed feeding these two types of larvae, we identified larval and nurse genes associated with caste development. Of 950 differentially expressed genes associated with caste, 82% were expressed in larvae with putative direct effects on larval caste, and 18% were expressed in nurses with putative indirect effects on caste. Estimated selection coefficients suggest that both nurse and larval genes putatively associated with caste are rapidly evolving, especially those genes associated with worker development. Altogether, our results suggest that indirect effect genes play important roles in both the expression and evolution of socially influenced traits such as caste.
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Affiliation(s)
- Svjetlana Vojvodic
- Center for Insect Science University of Arizona Tucson Arizona ; Department of Biological Sciences Rowan University Glassboro New Jersey
| | - Brian R Johnson
- Department of Entomology University of California Davis California
| | - Brock A Harpur
- Department of Biology York University Toronto Ontario Canada
| | - Clement F Kent
- Department of Biology York University Toronto Ontario Canada
| | - Amro Zayed
- Department of Biology York University Toronto Ontario Canada
| | - Kirk E Anderson
- Carl Hayden Bee Research Center USDA Tucson Arizona ; Department of Entomology University of Arizona Tucson Arizona
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Mikheyev AS, Linksvayer TA. Genes associated with ant social behavior show distinct transcriptional and evolutionary patterns. eLife 2015; 4:e04775. [PMID: 25621766 PMCID: PMC4383337 DOI: 10.7554/elife.04775] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 01/23/2015] [Indexed: 11/24/2022] Open
Abstract
Studies of the genetic basis and evolution of complex social behavior emphasize
either conserved or novel genes. To begin to reconcile these perspectives, we studied
how the evolutionary conservation of genes associated with social behavior depends on
regulatory context, and whether genes associated with social behavior exist in
distinct regulatory and evolutionary contexts. We identified modules of co-expressed
genes associated with age-based division of labor between nurses and foragers in the
ant Monomorium pharaonis, and we studied the relationship between
molecular evolution, connectivity, and expression. Highly connected and expressed
genes were more evolutionarily conserved, as expected. However, compared to the rest
of the genome, forager-upregulated genes were much more highly connected and
conserved, while nurse-upregulated genes were less connected and more evolutionarily
labile. Our results indicate that the genetic architecture of social behavior
includes both highly connected and conserved components as well as loosely connected
and evolutionarily labile components. DOI:http://dx.doi.org/10.7554/eLife.04775.001 Animal species vary widely in their degree of social behavior. Some species live
solitarily, and others, such as ants and humans, form large societies. Many
researchers have tried to understand the genetic changes underlying the evolution of
social behavior. Some researchers suggest that it involves recycling existing genes
that also have other conserved functions. Others propose that the evolution of social
behavior involves completely new genes that are not found in related but solitary
species. Ants are one of the best-studied social animals. An established colony can contain
many 1000s of individuals that live and work together and perform different roles.
The queen's job is to lay eggs, while the worker ants do everything else,
including collecting food, caring for the young, and protecting the colony. In some
species of ant—including the pharaoh ant—a worker's role changes
as it ages. Younger workers tend to stay in the nest and nurse the brood, while older
workers tend to leave the nest and forage for food. Mikheyev and Linksvayer asked: which genes are responsible for this age-based
division of labor? And how did this aspect of social behavior evolve? First, after
observing pharaoh ants from two colonies set up in the laboratory, they confirmed
that workers nursing the brood were on average almost a week younger than those seen
collecting food. Next Mikheyev and Linksvayer identified which genes were expressed
in ants of different ages, or ants engaged in different tasks. Specific sets of genes
were expressed more (or ‘up-regulated’) in nurse workers, while others
were up-regulated in foraging workers. Mikheyev and Linksvayer then investigated how rapidly these genes had evolved by
comparing them to related genes found in other social insects (fire ants and honey
bees). They also determined the ‘connectivity’ of these genes by asking
how many other genes showed similar expression patterns. In many organisms, how
rapidly a gene evolves depends on how tightly connected its expression is to the
expression of other genes; highly connected genes evolve more slowly. The genes that were expressed more in the older foraging workers were both more
highly connected and more evolutionarily conserved in the other social insects. Genes
that were up-regulated in the younger nurse workers were more loosely connected and
rapidly evolving. Mikheyev and Linksvayer's findings show that the evolution of social behavior
in animals involves both new genes, which tend to be loosely connected, and conserved
genes, which tend to be more highly connected. DOI:http://dx.doi.org/10.7554/eLife.04775.002
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Affiliation(s)
- Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
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Zuk M, Balenger SL. Behavioral ecology and genomics: new directions, or just a more detailed map? Behav Ecol 2014. [DOI: 10.1093/beheco/aru172] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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