1
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Quan PQ, Guo PL, He J, Liu XD. Heat-stress memory enhances the acclimation of a migratory insect pest to global warming. Mol Ecol 2024; 33:e17493. [PMID: 39132714 DOI: 10.1111/mec.17493] [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: 01/30/2024] [Revised: 07/18/2024] [Accepted: 08/02/2024] [Indexed: 08/13/2024]
Abstract
In the face of rising global temperatures, the mechanisms behind an organism's ability to acclimate to heat stress remain enigmatic. The rice leaf folder, Cnaphalocrocis medinalis, traditionally viewed as temperature-sensitive, paradoxically exhibits robust larval acclimation to heat stress. This study used the heat-acclimated strain HA39, developed through multigenerational exposure to 39°C during the larval stage, and the unacclimated strain HA27 reared at 27°C to unravel the transgenerational effects of heat acclimation and its regulatory mechanisms. Heat acclimation for larvae incurred a fitness cost in pupae when exposed to high temperature, yet a significant transgenerational effect surfaced, revealing heightened fitness benefit in pupae from HA39, even without additional heat exposure during larval recovery at 27°C. This transgenerational effect exhibited a short-term memory, diminishing after two recovery generations. Moreover, the effect correlated with increased superoxide dismutase (SOD) enzyme activity and expression levels of oxidoreductase genes, representing physiological and molecular foundations of heat acclimation. Heat-acclimated larvae displayed elevated DNA methylation levels, while pupae from HA39, in recovery generations, exhibited decreased methylation indicated by the upregulation of a demethylase gene and downregulation of two methyltransferase genes at high temperatures. In summary, heat acclimation induces DNA methylation, orchestrating heat-stress memory and influencing the expression levels of oxidoreductase genes and SOD activity. Heat-stress memory enhances the acclimation of the migratory insect pest to global warming.
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Affiliation(s)
- Peng-Qi Quan
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Pan-Long Guo
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Jing He
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Xiang-Dong Liu
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
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2
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Shang A, Bieszczad KM. Epigenetic mechanisms regulate cue memory underlying discriminative behavior. Neurosci Biobehav Rev 2022; 141:104811. [PMID: 35961385 DOI: 10.1016/j.neubiorev.2022.104811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/15/2022] [Accepted: 08/01/2022] [Indexed: 12/01/2022]
Abstract
The burgeoning field of neuroepigenetics has introduced chromatin modification as an important interface between experience and brain function. For example, epigenetic mechanisms like histone acetylation and DNA methylation operate throughout a lifetime to powerfully regulate gene expression in the brain that is required for experiences to be transformed into long-term memories. This review highlights emerging evidence from sensory models of memory that converge on the premise that epigenetic regulation of activity-dependent transcription in the sensory brain facilitates highly precise memory recall. Chromatin modifications may be key for neurophysiological responses to transient sensory cue features experienced in the "here and now" to be recapitulated over the long term. We conclude that the function of epigenetic control of sensory system neuroplasticity is to regulate the amount and type of sensory information retained in long-term memories by regulating neural representations of behaviorally relevant cues that guide behavior. This is of broad importance in the neuroscience field because there are few circumstances in which behavioral acts are devoid of an initiating sensory experience.
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Affiliation(s)
- Andrea Shang
- Dept. of Psychology - Behavioral and Systems Neuroscience, Rutgers University - New Brunswick, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Kasia M Bieszczad
- Dept. of Psychology - Behavioral and Systems Neuroscience, Rutgers University - New Brunswick, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA; Rutgers Center for Cognitive Science (RuCCS), Rutgers University, Piscataway, NJ 08854, USA; Department of Otolaryngology - Head and Neck Surgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08854, USA.
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3
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Gupta A, Nair S. Heritable Epigenomic Modifications Influence Stress Resilience and Rapid Adaptations in the Brown Planthopper ( Nilaparvata lugens). Int J Mol Sci 2022; 23:8728. [PMID: 35955860 PMCID: PMC9368798 DOI: 10.3390/ijms23158728] [Citation(s) in RCA: 6] [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] [Received: 07/06/2022] [Revised: 07/22/2022] [Accepted: 07/23/2022] [Indexed: 11/25/2022] Open
Abstract
DNA methylation in insects is integral to cellular differentiation, development, gene regulation, genome integrity, and phenotypic plasticity. However, its evolutionary potential and involvement in facilitating rapid adaptations in insects are enigmatic. Moreover, our understanding of these mechanisms is limited to a few insect species, of which none are pests of crops. Hence, we studied methylation patterns in the brown planthopper (BPH), a major rice pest, under pesticide and nutritional stress, across its life stages. Moreover, as the inheritance of epigenetic changes is fundamentally essential for acclimation, adaptability, and evolution, we determined the heritability and persistence of stress-induced methylation marks in BPH across generations. Our results revealed that DNA methylation pattern(s) in BPH varies/vary with environmental cues and is/are insect life-stage specific. Further, our findings provide novel insights into the heritability of stress-induced methylation marks in BPH. However, it was observed that, though heritable, these marks eventually fade in the absence of the stressors, thereby suggesting the existence of fitness cost(s) associated with the maintenance of the stressed epigenotype. Furthermore, we demonstrate how 5-azacytidine-mediated disruption of BPH methylome influences expression levels of stress-responsive genes and, thereby, highlight demethylation/methylation as a phenomenon underlying stress resilience of BPH.
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Affiliation(s)
| | - Suresh Nair
- Plant-Insect Interaction Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi 110067, India
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4
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Morandin C, Brendel VP. Tools and applications for integrative analysis of DNA methylation in social insects. Mol Ecol Resour 2021; 22:1656-1674. [PMID: 34861105 DOI: 10.1111/1755-0998.13566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 12/15/2022]
Abstract
DNA methylation is a common epigenetic signalling tool and an important biological process which is widely studied in a large array of species. The presence, level and function of DNA methylation vary greatly across species. In some insects, DNA methylation systems are minimal, and overall methylation rates tend to be low in all studied insect species. Low methylation levels probed by whole-genome bisulphite sequencing require great care with respect to data quality control and interpretation. Here, we introduce BWASP/R, a complete workflow that allows efficient, scalable and entirely reproducible analyses of raw DNA methylation sequencing data. Consistent application of quality control filters and analysis parameters provides fair comparisons among different studies and an integrated view of all experiments on one species. We describe the capabilities of the BWASP/R workflow by re-analysing several publicly available social insect WGBS data sets, comprising 70 samples and cumulatively 147 replicates from four different species. We show that the CpG methylome comprises only about 1.5% of CpG sites in the honeybee genome and that the cumulative data are consistent with genetic signatures of site accessibility and physiological control of methylation levels.
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Affiliation(s)
- Claire Morandin
- Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland
| | - Volker P Brendel
- Departments of Biology and Computer Science, Indiana University, Bloomingto, Indiana, USA
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5
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Cardoso-Júnior CAM, Yagound B, Ronai I, Remnant EJ, Hartfelder K, Oldroyd BP. DNA methylation is not a driver of gene expression reprogramming in young honey bee workers. Mol Ecol 2021; 30:4804-4818. [PMID: 34322926 DOI: 10.1111/mec.16098] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/06/2021] [Accepted: 07/16/2021] [Indexed: 12/01/2022]
Abstract
The presence of DNA methylation marks within genic intervals, also called gene body methylation, is an evolutionarily-conserved epigenetic hallmark of animal and plant methylomes. In social insects, gene body methylation is thought to contribute to behavioural plasticity, for example between foragers and nurse workers, by modulating gene expression. However, recent studies have suggested that the majority of DNA methylation is sequence-specific, and therefore cannot act as a flexible mediator between environmental cues and gene expression. To address this paradox, we examined whole-genome methylation patterns in the brains and ovaries of young honey bee workers that had been subjected to divergent social contexts: the presence or absence of the queen. Although these social contexts are known to bring about extreme changes in behavioral and reproductive traits through differential gene expression, we found no significant differences between the methylomes of workers from queenright and queenless colonies. In contrast, thousands of regions were differentially methylated between colonies, and these differences were not associated with differential gene expression in the subset of genes examined. Methylation patterns were highly similar between brain and ovary tissues and only differed in nine regions. These results strongly indicate that DNA methylation is not a driver of differential gene expression between tissues or behavioral morphs. Finally, despite the lack of difference in methylation patterns, queen presence affected the expression of all four DNA methyltransferase genes, suggesting that these enzymes have roles beyond DNA methylation. Therefore, the functional role of DNA methylation in social insect genomes remains an open question.
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Affiliation(s)
- Carlos A M Cardoso-Júnior
- Departamento de Biologia Celular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil.,Behaviour, Ecology and Evolution (BEE) Laboratory, Ecology and Evolution, School of Life and Environmental Sciences A12, University of Sydney, Sydney, NSW, Australia
| | - Boris Yagound
- Behaviour, Ecology and Evolution (BEE) Laboratory, Ecology and Evolution, School of Life and Environmental Sciences A12, University of Sydney, Sydney, NSW, Australia
| | - Isobel Ronai
- Behaviour, Ecology and Evolution (BEE) Laboratory, Ecology and Evolution, School of Life and Environmental Sciences A12, University of Sydney, Sydney, NSW, Australia
| | - Emily J Remnant
- Behaviour, Ecology and Evolution (BEE) Laboratory, Ecology and Evolution, School of Life and Environmental Sciences A12, University of Sydney, Sydney, NSW, Australia
| | - Klaus Hartfelder
- Departamento de Biologia Celular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil
| | - Benjamin P Oldroyd
- Behaviour, Ecology and Evolution (BEE) Laboratory, Ecology and Evolution, School of Life and Environmental Sciences A12, University of Sydney, Sydney, NSW, Australia.,Wissenschaftskolleg zu Berlin, Berlin, Germany
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6
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Palli SR. Epigenetic regulation of post-embryonic development. CURRENT OPINION IN INSECT SCIENCE 2021; 43:63-69. [PMID: 33068783 PMCID: PMC8044252 DOI: 10.1016/j.cois.2020.09.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/09/2020] [Accepted: 09/18/2020] [Indexed: 05/02/2023]
Abstract
Modifications to DNA and core histones influence chromatin organization and expression of the genome. DNA methylation plays a significant role in the regulation of multiple biological processes that regulate behavior and caste differentiation in social insects. Histone modifications play significant roles in the regulation of development and reproduction in other insects. Genes coding for acetyltransferases, deacetylases, methyltransferases, and demethylases that modify core histones have been identified in genomes of multiple insects. Studies on the function and mechanisms of action of some of these enzymes uncovered their contribution to post-embryonic development. The results from studies on epigenetic modifiers could help in the identification of inhibitors of epigenetic modifiers that could be developed to control pests and disease vectors.
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Affiliation(s)
- Subba Reddy Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, S225 Ag. Science N, Lexington, KY 40546, United States.
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7
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Abstract
With less than a million neurons, the western honeybee Apis mellifera is capable of complex olfactory behaviors and provides an ideal model for investigating the neurophysiology of the olfactory circuit and the basis of olfactory perception and learning. Here, we review the most fundamental aspects of honeybee's olfaction: first, we discuss which odorants dominate its environment, and how bees use them to communicate and regulate colony homeostasis; then, we describe the neuroanatomy and the neurophysiology of the olfactory circuit; finally, we explore the cellular and molecular mechanisms leading to olfactory memory formation. The vastity of histological, neurophysiological, and behavioral data collected during the last century, together with new technological advancements, including genetic tools, confirm the honeybee as an attractive research model for understanding olfactory coding and learning.
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Affiliation(s)
- Marco Paoli
- Research Centre on Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 31062, Toulouse, France.
| | - Giovanni C Galizia
- Department of Neuroscience, University of Konstanz, 78457, Konstanz, Germany.
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8
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Villagra C, Frías-Lasserre D. Epigenetic Molecular Mechanisms in Insects. NEOTROPICAL ENTOMOLOGY 2020; 49:615-642. [PMID: 32514997 DOI: 10.1007/s13744-020-00777-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
Insects are the largest animal group on Earth both in biomass and diversity. Their outstanding success has inspired genetics and developmental research, allowing the discovery of dynamic process explaining extreme phenotypic plasticity and canalization. Epigenetic molecular mechanisms (EMMs) are vital for several housekeeping functions in multicellular organisms, regulating developmental, ontogenetic trajectories and environmental adaptations. In Insecta, EMMs are involved in the development of extreme phenotypic divergences such as polyphenisms and eusocial castes. Here, we review the history of this research field and how the main EMMs found in insects help to understand their biological processes and diversity. EMMs in insects confer them rapid response capacity allowing insect either to change with plastic divergence or to keep constant when facing different stressors or stimuli. EMMs function both at intra as well as transgenerational scales, playing important roles in insect ecology and evolution. We discuss on how EMMs pervasive influences in Insecta require not only the control of gene expression but also the dynamic interplay of EMMs with further regulatory levels, including genetic, physiological, behavioral, and environmental among others, as was earlier proposed by the Probabilistic Epigenesis model and Developmental System Theory.
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Affiliation(s)
- C Villagra
- Instituto de Entomología, Univ Metropolitana de Ciencias de la Educación, Santiago, Chile.
| | - D Frías-Lasserre
- Instituto de Entomología, Univ Metropolitana de Ciencias de la Educación, Santiago, Chile
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9
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Nikitin V, Solntseva S, Kozyrev S, Nikitin P. Long-term memory consolidation or reconsolidation impairment induces amnesia with key characteristics that are similar to key learning characteristics. Neurosci Biobehav Rev 2020; 108:542-558. [DOI: 10.1016/j.neubiorev.2019.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 09/16/2019] [Accepted: 12/03/2019] [Indexed: 02/07/2023]
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10
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Zhang V, Kucharski R, Landers C, Richards SN, Bröer S, Martin RE, Maleszka R. Characterization of a Dopamine Transporter and Its Splice Variant Reveals Novel Features of Dopaminergic Regulation in the Honey Bee. Front Physiol 2019; 10:1375. [PMID: 31736791 PMCID: PMC6838227 DOI: 10.3389/fphys.2019.01375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/17/2019] [Indexed: 11/25/2022] Open
Abstract
Dopamine is an important neuromodulator involved in reward-processing, movement control, motivational responses, and other aspects of behavior in most animals. In honey bees (Apis mellifera), the dopaminergic system has been implicated in an elaborate pheromonal communication network between individuals and in the differentiation of females into reproductive (queen) and sterile (worker) castes. Here we have identified and characterized a honey bee dopamine transporter (AmDAT) and a splice variant lacking exon 3 (AmDATΔex3). Both transcripts are present in the adult brain and antennae as well as at lower levels within larvae and ovaries. When expressed separately in the Xenopus oocyte system, AmDAT localizes to the oocyte surface whereas the splice variant is retained at an internal membrane. Oocytes expressing AmDAT exhibit a 12-fold increase in the uptake of [3H]dopamine relative to non-injected oocytes, whereas the AmDATΔex3-expressing oocytes show no change in [3H]dopamine transport. Electrophysiological measurements of AmDAT activity revealed it to be a high-affinity, low-capacity transporter of dopamine. The transporter also recognizes noradrenaline as a major substrate and tyramine as a minor substrate, but does not transport octopamine, L-Dopa, or serotonin. Dopamine transport via AmDAT is inhibited by cocaine in a reversible manner, but is unaffected by octopamine. Co-expression of AmDAT and AmDATΔex3 in oocytes results in a substantial reduction in AmDAT-mediated transport, which was also detected as a significant decrease in the level of AmDAT protein. This down-regulatory effect is not attributable to competition with AmDATΔex3 for ER ribosomes, nor to a general inhibition of the oocyte's translational machinery. In vivo, the expression of both transcripts shows a high level of inter-individual variability. Gene-focused, ultra-deep amplicon sequencing detected methylation of the amdat locus at ten 5'-C-phosphate-G-3' dinucleotides (CpGs), but only in 5-10% of all reads in whole brains or antennae. These observations, together with the localization of the amdat transcript to a few clusters of dopaminergic neurons, imply that amdat methylation is positively linked to its transcription. Our findings suggest that multiple cellular mechanisms, including gene splicing and epigenomic communication systems, may be adopted to increase the potential of a conserved gene to contribute to lineage-specific behavioral outcomes.
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Affiliation(s)
- Vicky Zhang
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Robert Kucharski
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Faculty of Science and Technology, University of Canberra, Bruce, ACT, Australia
| | - Courtney Landers
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Sashika N. Richards
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Rowena E. Martin
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Ryszard Maleszka
- Research School of Biology, The Australian National University, Canberra, ACT, Australia
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11
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Morandin C, Brendel VP, Sundström L, Helanterä H, Mikheyev AS. Changes in gene DNA methylation and expression networks accompany caste specialization and age-related physiological changes in a social insect. Mol Ecol 2019; 28:1975-1993. [PMID: 30809873 DOI: 10.1111/mec.15062] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/21/2019] [Accepted: 02/21/2019] [Indexed: 12/14/2022]
Abstract
Social insects provide systems for studying epigenetic regulation of phenotypes, particularly with respect to differentiation of reproductive and worker castes, which typically arise from a common genetic background. The role of gene expression in caste specialization has been extensively studied, but the role of DNA methylation remains controversial. Here, we perform well replicated, integrated analyses of DNA methylation and gene expression in brains of an ant (Formica exsecta) with distinct female castes using traditional approaches (tests of differential methylation) combined with a novel approach (analysis of co-expression and co-methylation networks). We found differences in expression and methylation profiles between workers and queens at different life stages, as well as some overlap between DNA methylation and expression at the functional level. Large portions of the transcriptome and methylome are organized into "modules" of genes, some significantly associated with phenotypic traits of castes and developmental stages. Several gene co-expression modules are preserved in co-methylation networks, consistent with possible regulation of caste-specific gene expression by DNA methylation. Surprisingly, brain co-expression modules were highly preserved when compared with a previous study that examined whole-body co-expression patterns in 16 ant species, suggesting that these modules are evolutionarily conserved and for specific functions in various tissues. Altogether, these results suggest that DNA methylation participates in regulation of caste specialization and age-related physiological changes in social insects.
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Affiliation(s)
- Claire Morandin
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Åbo, Finland.,Department of Ecology and Evolution, Biophore, University of Lausanne, Lausanne, Switzerland
| | - Volker P Brendel
- Department of Biology, Indiana University, Bloomington, Indiana.,Department of Computer Science, Indiana University, Bloomington, Indiana
| | - Liselotte Sundström
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Tvärminne Zoological Station, University of Helsinki, Hanko, Finland
| | - Heikki Helanterä
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Ecology and Genetics Research Unit, Faculty of Science, University of Oulu, Oulu, Finland
| | - Alexander S Mikheyev
- Okinawa Institute of Science and Technology, Okinawa, Japan.,Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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12
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Alleman A, Stoldt M, Feldmeyer B, Foitzik S. Tandem-running and scouting behaviour are characterized by up-regulation of learning and memory formation genes within the ant brain. Mol Ecol 2019; 28:2342-2359. [PMID: 30903719 DOI: 10.1111/mec.15079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 03/09/2019] [Accepted: 03/12/2019] [Indexed: 12/13/2022]
Abstract
Tandem-running is a recruitment behaviour in ants that has been described as a form of teaching, where spatial information possessed by a leader is conveyed to following nestmates. Within Temnothorax ants, tandem-running is used within a variety of contexts, from foraging and nest relocation to-in the case of slavemaking species-slave raiding. Here, we elucidate the transcriptomic basis of scouting, tandem-leading and tandem-following behaviours across two species with divergent lifestyles: the slavemaking Temnothorax americanus and its primary, nonparasitic host T. longispinosus. Analysis of gene expression data from brains revealed that only a small number of unique differentially expressed genes are responsible for scouting and tandem-running. Comparison of orthologous genes between T. americanus and T. longispinosus suggests that tandem-running is characterized by species-specific patterns of gene usage. However, within both species, tandem-leaders showed gene expression patterns median to those of scouts and tandem-followers, which was expected, as leaders can be recruited from either of the other two behavioural states. Most importantly, a number of differentially expressed behavioural genes were found, with functions relating to learning and memory formation in other social and nonsocial insects. This includes a number of up-regulated receptor genes such as a glutamate and dopamine receptor, as well as serine/threonine-protein phosphatases and kinases. Learning and memory genes were specifically up-regulated within scouts and tandem-followers, not only reinforcing previous behavioural studies into how Temnothorax navigate novel environments and share information, but also providing insight into the molecular underpinnings of teaching and learning within social insects.
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Affiliation(s)
- Austin Alleman
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Marah Stoldt
- 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
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
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13
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Nikitin VP, Kozyrev SA, Solntseva SV. Peculiarities of Participation of DNA Methyltransferases in the Mechanisms of Storage, Impairment, and Recovery of Conditioned Food Aversion Memory. Bull Exp Biol Med 2018; 166:1-6. [PMID: 30417305 DOI: 10.1007/s10517-018-4275-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Indexed: 12/31/2022]
Abstract
We studied the participation of DNA-methylation processes in the mechanisms of memory storage and reconsolidation, amnesia induction, and in recovery of the conditioned food aversion memory in edible snails. It was found that daily injections of DNA methyltransferases inhibitor over 3 days combined with a reminder of a conditioned food stimulus did not affect memory storage. The administration of DNA methyltransferase inhibitors did not suppress induction of amnesia caused the NMDA receptor antagonist/reminder. Injections of DNA methyltransferase inhibitors combined with the reminder led to memory recovery in 3 days after amnesia induction. Thus, DNA methyltransferase inhibitors in the same doses did not affect storage and reconsolidation of memory, as well as the mechanisms of amnesia induction. At the same time, injections of inhibitors led to memory recovery, apparently, due to disruption of reactivation and amnesia development.
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Affiliation(s)
- V P Nikitin
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia.
| | - S A Kozyrev
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia
| | - S V Solntseva
- P. K. Anokhin Research Institute of Normal Physiology, Moscow, Russia
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14
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Vorster AP, Born J. Wakefulness rather than sleep benefits extinction of an inhibitory operant conditioning memory in Aplysia. Neurobiol Learn Mem 2018; 155:306-312. [DOI: 10.1016/j.nlm.2018.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 04/20/2018] [Accepted: 07/27/2018] [Indexed: 01/16/2023]
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15
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Søvik E, Berthier P, Klare WP, Helliwell P, Buckle ELS, Plath JA, Barron AB, Maleszka R. Cocaine Directly Impairs Memory Extinction and Alters Brain DNA Methylation Dynamics in Honey Bees. Front Physiol 2018; 9:79. [PMID: 29487536 PMCID: PMC5816933 DOI: 10.3389/fphys.2018.00079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 01/22/2018] [Indexed: 12/11/2022] Open
Abstract
Drug addiction is a chronic relapsing behavioral disorder. The high relapse rate has often been attributed to the perseverance of drug-associated memories due to high incentive salience of stimuli learnt under the influence of drugs. Drug addiction has also been interpreted as a memory disorder since drug associated memories are unusually enduring and some drugs, such as cocaine, interfere with neuroepigenetic machinery known to be involved in memory processing. Here we used the honey bee (an established invertebrate model for epigenomics and behavioral studies) to examine whether or not cocaine affects memory processing independently of its effect on incentive salience. Using the proboscis extension reflex training paradigm we found that cocaine strongly impairs consolidation of extinction memory. Based on correlation between the observed effect of cocaine on learning and expression of epigenetic processes, we propose that cocaine interferes with memory processing independently of incentive salience by directly altering DNA methylation dynamics. Our findings emphasize the impact of cocaine on memory systems, with relevance for understanding how cocaine can have such an enduring impact on behavior.
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Affiliation(s)
- Eirik Søvik
- Department of Science and Mathematics, Volda University College, Volda, Norway
| | - Pauline Berthier
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - William P Klare
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Paul Helliwell
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Edwina L S Buckle
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Jenny A Plath
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Andrew B Barron
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ryszard Maleszka
- Research School of Biology, Australian National University, Canberra, ACT, Australia
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16
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Shvetsov AV, Lopatina NG, Vaido AI. Histone H3 methylation at lysine 4 is involved in long-term memory formation in the honeybee Apis mellifera L. J EVOL BIOCHEM PHYS+ 2018. [DOI: 10.1134/s0022093017060072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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CREB-binding protein plays key roles in juvenile hormone action in the red flour beetle, Tribolium Castaneum. Sci Rep 2018; 8:1426. [PMID: 29362416 PMCID: PMC5780420 DOI: 10.1038/s41598-018-19667-6] [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: 09/21/2017] [Accepted: 01/05/2018] [Indexed: 12/23/2022] Open
Abstract
Juvenile hormones (JH) and ecdysteroids regulate many biological and metabolic processes. CREB-binding protein (CBP) is a transcriptional co-regulator with histone acetyltransferase (HAT) activity. Therefore, CBP is involved in activation of many transcription factors that regulate expression of genes associated with postembryonic development in insects. However, the function of CBP in JH action in insects is not well understood. Hence, we studied the role of CBP in JH action in the red flour beetle, Tribolium castaneum and the Tribolium cell line. CBP knockdown caused a decrease in JH induction of genes, Kr-h1, 4EBP and G13402 in T. castaneum larvae, adults and TcA cells whereas, Trichostatin A [TSA, a histone deacetylase (HDAC) inhibitor] induced the expression of these JH-response genes. Western blot analysis with specific antibodies revealed the requirement of CBP for the acetylation of H3K18 and H3K27 in both T. castaneum and TcA cells. Chromatin immunoprecipitation (Chip) assays showed the importance of CBP-mediated acetylation of H3K27 for JH induction of Kr-h1, 4EBP, and G13402 in TcA cells. These data suggest that CBP plays an important role in JH action in the model insect, T.castaneum.
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Cardoso-Júnior CAM, Guidugli-Lazzarini KR, Hartfelder K. DNA methylation affects the lifespan of honey bee (Apis mellifera L.) workers - Evidence for a regulatory module that involves vitellogenin expression but is independent of juvenile hormone function. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 92:21-29. [PMID: 29157677 DOI: 10.1016/j.ibmb.2017.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
The canonic regulatory module for lifespan of honey bee (Apis mellifera) workers involves a mutual repressor relationship between juvenile hormone (JH) and vitellogenin (Vg). Compared to vertebrates, however, little is known about a possible role of epigenetic factors. The full genomic repertoire of DNA methyltransferases (DNMTs) makes the honey bee an attractive emergent model for studying the role of epigenetics in the aging process of invertebrates, and especially so in social insects. We first quantified the transcript levels of the four DNMTs encoding genes in the head thorax and abdomens of workers of different age, showing that dnmt1a and dnmt3 expression is up-regulated in abdomens of old workers, whereas dnmt1b and dnmt2 are down-regulated in heads of old workers. Pharmacological genome demethylation by RG108 treatment caused an increase in worker lifespan. Next, we showed that the genomic DNA methylation status indirectly affects vitellogenin gene expression both in vitro and in vivo in young workers, and that this occurs independent of caloric restriction or JH levels, suggesting that a non-canonical circuitry may be acting in parallel with the JH/Vg module to regulate the adult life cycle of honey bee workers. Our data provide evidence that epigenetic factors play a role in regulatory networks associated with complex life history traits of a social insect.
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Affiliation(s)
- Carlos A M Cardoso-Júnior
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Karina R Guidugli-Lazzarini
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Klaus Hartfelder
- Departamento de Biologia Celular, Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14049-900, Brazil.
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19
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Genome-wide DNA methylation changes associated with olfactory learning and memory in Apis mellifera. Sci Rep 2017; 7:17017. [PMID: 29208987 PMCID: PMC5717273 DOI: 10.1038/s41598-017-17046-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 11/08/2017] [Indexed: 12/25/2022] Open
Abstract
The honeybee is a model organism for studying learning and memory formation and its underlying molecular mechanisms. While DNA methylation is well studied in caste differentiation, its role in learning and memory is not clear in honeybees. Here, we analyzed genome-wide DNA methylation changes during olfactory learning and memory process in A. mellifera using whole genome bisulfite sequencing (WGBS) method. A total of 853 significantly differentially methylated regions (DMRs) and 963 differentially methylated genes (DMGs) were identified. We discovered that 440 DMRs of 648 genes were hypermethylated and 274 DMRs of 336 genes were hypomethylated in trained group compared to untrained group. Of these DMGs, many are critical genes involved in learning and memory, such as Creb, GABABR and Ip3k, indicating extensive involvement of DNA methylation in honeybee olfactory learning and memory process. Furthermore, key enzymes for histone methylation, RNA editing and miRNA processing also showed methylation changes during this process, implying that DNA methylation can affect learning and memory of honeybees by regulating other epigenetic modification processes.
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20
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Cardoso-Júnior CAM, Fujimura PT, Santos-Júnior CD, Borges NA, Ueira-Vieira C, Hartfelder K, Goulart LR, Bonetti AM. Epigenetic modifications and their relation to caste and sex determination and adult division of labor in the stingless bee Melipona scutellaris. Genet Mol Biol 2017; 40:61-68. [PMID: 28257527 PMCID: PMC5409779 DOI: 10.1590/1678-4685-gmb-2016-0242] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 01/12/2017] [Indexed: 12/03/2022] Open
Abstract
Stingless bees of the genus Melipona, have long been considered an
enigmatic case among social insects for their mode of caste determination, where in
addition to larval food type and quantity, the genotype also has a saying, as
proposed over 50 years ago by Warwick E. Kerr. Several attempts have since tried to
test his Mendelian two-loci/two-alleles segregation hypothesis, but only recently a
single gene crucial for sex determination in bees was evidenced to be
sex-specifically spliced and also caste-specifically expressed in a
Melipona species. Since alternative splicing is frequently
associated with epigenetic marks, and the epigenetic status plays a major role in
setting the caste phenotype in the honey bee, we investigated here epigenetic
chromatin modification in the stingless bee Melipona scutellaris. We
used an ELISA-based methodology to quantify global methylation status and western
blot assays to reveal histone modifications. The results evidenced DNA
methylation/demethylation events in larvae and pupae, and significant differences in
histone methylation and phosphorylation between newly emerged adult queens and
workers. The epigenetic dynamics seen in this stingless bee species represent a new
facet in the caste determination process in Melipona bees and
suggest a possible mechanism that is likely to link a genotype component to the
larval diet and adult social behavior of these bees.
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Affiliation(s)
- Carlos A M Cardoso-Júnior
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.,Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Patrícia Tieme Fujimura
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Naiara Araújo Borges
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Carlos Ueira-Vieira
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Klaus Hartfelder
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Luiz Ricardo Goulart
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | - Ana Maria Bonetti
- Departamento de Genética e Bioquímica, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
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21
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Biergans SD, Claudianos C, Reinhard J, Galizia CG. DNA methylation mediates neural processing after odor learning in the honeybee. Sci Rep 2017; 7:43635. [PMID: 28240742 PMCID: PMC5378914 DOI: 10.1038/srep43635] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 01/26/2017] [Indexed: 01/04/2023] Open
Abstract
DNA methyltransferases (Dnmts) - epigenetic writers catalyzing the transfer of methyl-groups to cytosine (DNA methylation) - regulate different aspects of memory formation in many animal species. In honeybees, Dnmt activity is required to adjust the specificity of olfactory reward memories and bees' relearning capability. The physiological relevance of Dnmt-mediated DNA methylation in neural networks, however, remains unknown. Here, we investigated how Dnmt activity impacts neuroplasticity in the bees' primary olfactory center, the antennal lobe (AL) an equivalent of the vertebrate olfactory bulb. The AL is crucial for odor discrimination, an indispensable process in forming specific odor memories. Using pharmacological inhibition, we demonstrate that Dnmt activity influences neural network properties during memory formation in vivo. We show that Dnmt activity promotes fast odor pattern separation in trained bees. Furthermore, Dnmt activity during memory formation increases both the number of responding glomeruli and the response magnitude to a novel odor. These data suggest that Dnmt activity is necessary for a form of homoeostatic network control which might involve inhibitory interneurons in the AL network.
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Affiliation(s)
- Stephanie D Biergans
- Queensland Brain Institute, The University of Queensland, Australia.,Neurobiologie, Universität Konstanz, Germany
| | - Charles Claudianos
- Queensland Brain Institute, The University of Queensland, Australia.,Monash Institute of Cognitive and Clinical Neuroscience, Faculty of Medicine, Nursing Health and Sciences, Monash University, Australia
| | - Judith Reinhard
- Queensland Brain Institute, The University of Queensland, Australia
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Toth AL, Rehan SM. Molecular Evolution of Insect Sociality: An Eco-Evo-Devo Perspective. ANNUAL REVIEW OF ENTOMOLOGY 2017; 62:419-442. [PMID: 27912247 DOI: 10.1146/annurev-ento-031616-035601] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The evolution of eusociality is a perennial issue in evolutionary biology, and genomic advances have fueled steadily growing interest in the genetic changes underlying social evolution. Along with a recent flurry of research on comparative and evolutionary genomics in different eusocial insect groups (bees, ants, wasps, and termites), several mechanistic explanations have emerged to describe the molecular evolution of eusociality from solitary behavior. These include solitary physiological ground plans, genetic toolkits of deeply conserved genes, evolutionary changes in protein-coding genes, cis regulation, and the structure of gene networks, epigenetics, and novel genes. Despite this proliferation of ideas, there has been little synthesis, even though these ideas are not mutually exclusive and may in fact be complementary. We review available data on molecular evolution of insect sociality and highlight key biotic and abiotic factors influencing social insect genomes. We then suggest both phylogenetic and ecological evolutionary developmental biology (eco-evo-devo) perspectives for a more synthetic view of molecular evolution in insect societies.
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Affiliation(s)
- Amy L Toth
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa 50011;
- Department of Entomology, Iowa State University, Ames, Iowa 50011
| | - Sandra M Rehan
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire 03824;
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23
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Biergans SD, Claudianos C, Reinhard J, Galizia CG. DNA Methylation Adjusts the Specificity of Memories Depending on the Learning Context and Promotes Relearning in Honeybees. Front Mol Neurosci 2016; 9:82. [PMID: 27672359 PMCID: PMC5018481 DOI: 10.3389/fnmol.2016.00082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/25/2016] [Indexed: 12/29/2022] Open
Abstract
The activity of the epigenetic writers DNA methyltransferases (Dnmts) after olfactory reward conditioning is important for both stimulus-specific long-term memory (LTM) formation and extinction. It, however, remains unknown which components of memory formation Dnmts regulate (e.g., associative vs. non-associative) and in what context (e.g., varying training conditions). Here, we address these aspects in order to clarify the role of Dnmt-mediated DNA methylation in memory formation. We used a pharmacological Dnmt inhibitor and classical appetitive conditioning in the honeybee Apis mellifera, a well characterized model for classical conditioning. We quantified the effect of DNA methylation on naïve odor and sugar responses, and on responses following olfactory reward conditioning. We show that (1) Dnmts do not influence naïve odor or sugar responses, (2) Dnmts do not affect the learning of new stimuli, but (3) Dnmts influence odor-coding, i.e., 'correct' (stimulus-specific) LTM formation. Particularly, Dnmts reduce memory specificity when experience is low (one-trial training), and increase memory specificity when experience is high (multiple-trial training), generating an ecologically more useful response to learning. (4) In reversal learning conditions, Dnmts are involved in regulating both excitatory (re-acquisition) and inhibitory (forgetting) processes.
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Affiliation(s)
- Stephanie D Biergans
- Queensland Brain Institute, University of Queensland, BrisbaneQLD, Australia; Neurobiologie, Universität KonstanzKonstanz, Germany
| | - Charles Claudianos
- Queensland Brain Institute, University of Queensland, BrisbaneQLD, Australia; Monash Institute of Cognitive and Clinical Neuroscience, Faculty of Biomedical and Psychological Sciences, Monash University, MelbourneVIC, Australia
| | - Judith Reinhard
- Queensland Brain Institute, University of Queensland, Brisbane QLD, Australia
| | - C G Galizia
- Neurobiologie, Universität Konstanz Konstanz, Germany
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24
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Kim D, Thairu MW, Hansen AK. Novel Insights into Insect-Microbe Interactions-Role of Epigenomics and Small RNAs. FRONTIERS IN PLANT SCIENCE 2016; 7:1164. [PMID: 27540386 PMCID: PMC4972996 DOI: 10.3389/fpls.2016.01164] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/20/2016] [Indexed: 05/23/2023]
Abstract
It has become increasingly clear that microbes form close associations with the vast majority of animal species, especially insects. In fact, an array of diverse microbes is known to form shared metabolic pathways with their insect hosts. A growing area of research in insect-microbe interactions, notably for hemipteran insects and their mutualistic symbionts, is to elucidate the regulation of this inter-domain metabolism. This review examines two new emerging mechanisms of gene regulation and their importance in host-microbe interactions. Specifically, we highlight how the incipient areas of research on regulatory "dark matter" such as epigenomics and small RNAs, can play a pivotal role in the evolution of both insect and microbe gene regulation. We then propose specific models of how these dynamic forms of gene regulation can influence insect-symbiont-plant interactions. Future studies in this area of research will give us a systematic understanding of how these symbiotic microbes and animals reciprocally respond to and regulate their shared metabolic processes.
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25
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Gong Z, Wang C, Nieh JC, Tan K. Inhibiting DNA methylation alters olfactory extinction but not acquisition learning in Apis cerana and Apis mellifera. JOURNAL OF INSECT PHYSIOLOGY 2016; 90:43-48. [PMID: 27262427 DOI: 10.1016/j.jinsphys.2016.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 05/29/2016] [Accepted: 05/30/2016] [Indexed: 06/05/2023]
Abstract
DNA methylation plays a key role in invertebrate acquisition and extinction memory. Honey bees have excellent olfactory learning, but the role of DNA methylation in memory formation has, to date, only been studied in Apis mellifera. We inhibited DNA methylation by inhibiting DNA methyltransferase (DNMT) with zebularine (zeb) and studied the resulting effects upon olfactory acquisition and extinction memory in two honey bee species, Apis cerana and A. mellifera. We used the proboscis extension reflex (PER) assay to measure memory. We provide the first demonstration that DNA methylation is also important in the olfactory extinction learning of A. cerana. DNMT did not reduce acquisition learning in either species. However, zeb bidirectionally and differentially altered extinction learning in both species. In particular, zeb provided 1h before acquisition learning improved extinction memory retention in A. mellifera, but reduced extinction memory retention in A. cerana. The reasons for these differences are unclear, but provide a basis for future studies to explore species-specific differences in the effects of methylation on memory formation.
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Affiliation(s)
- Zhiwen Gong
- Eastern Bee Research Institute of Yunnan Agricultural University, Kunming, Yunnan Province, China; Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, Kunming, Yunnan Province, China
| | - Chao Wang
- Eastern Bee Research Institute of Yunnan Agricultural University, Kunming, Yunnan Province, China
| | - James C Nieh
- Division of Biological Sciences, Section of Ecology, Behavior, and Evolution, University of California, San Diego, La Jolla, CA, USA
| | - Ken Tan
- Eastern Bee Research Institute of Yunnan Agricultural University, Kunming, Yunnan Province, China; Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, Kunming, Yunnan Province, China.
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26
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Becker N, Kucharski R, Rössler W, Maleszka R. Age-dependent transcriptional and epigenomic responses to light exposure in the honey bee brain. FEBS Open Bio 2016; 6:622-39. [PMID: 27398303 PMCID: PMC4932443 DOI: 10.1002/2211-5463.12084] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 05/02/2016] [Accepted: 05/09/2016] [Indexed: 01/21/2023] Open
Abstract
Light is a powerful environmental stimulus of special importance in social honey bees that undergo a behavioral transition from in-hive to outdoor foraging duties. Our previous work has shown that light exposure induces structural neuronal plasticity in the mushroom bodies (MBs), a brain center implicated in processing inputs from sensory modalities. Here, we extended these analyses to the molecular level to unravel light-induced transcriptomic and epigenomic changes in the honey bee brain. We have compared gene expression in brain compartments of 1- and 7-day-old light-exposed honey bees with age-matched dark-kept individuals. We have found a number of differentially expressed genes (DEGs), both novel and conserved, including several genes with reported roles in neuronal plasticity. Most of the DEGs show age-related changes in the amplitude of light-induced expression and are likely to be both developmentally and environmentally regulated. Some of the DEGs are either known to be methylated or are implicated in epigenetic processes suggesting that responses to light exposure are at least partly regulated at the epigenome level. Consistent with this idea light alters the DNA methylation pattern of bgm, one of the DEGs affected by light exposure, and the expression of microRNA miR-932. This confirms the usefulness of our approach to identify candidate genes for neuronal plasticity and provides evidence for the role of epigenetic processes in driving the molecular responses to visual stimulation.
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Affiliation(s)
- Nils Becker
- Behavioral Physiology and Sociobiology Biozentrum University of Würzburg Germany
| | - Robert Kucharski
- Research School of Biology The Australian National University Acton Australia
| | - Wolfgang Rössler
- Behavioral Physiology and Sociobiology Biozentrum University of Würzburg Germany
| | - Ryszard Maleszka
- Research School of Biology The Australian National University Acton Australia
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27
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Rusch C, Broadhead GT, Raguso RA, Riffell JA. Olfaction in context-sources of nuance in plant-pollinator communication. CURRENT OPINION IN INSECT SCIENCE 2016; 15:53-60. [PMID: 27436732 DOI: 10.1016/j.cois.2016.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 03/12/2016] [Accepted: 03/15/2016] [Indexed: 05/09/2023]
Abstract
Floral scents act as long-distance signals to attract pollinators, but volatiles emitted from the vegetation and neighboring plant community may modify this mutualistic communication system. What impact does the olfactory background have on pollination systems and their evolution? We consider recent behavioral studies that address the context of when and where volatile backgrounds influence a pollinator's perception of floral blends. In parallel, we review neurophysiological studies that show the importance of blend composition and background in modifying the representation of floral blends in the pollinator brain, as well as experience-dependent plasticity in increasing the representation of a rewarding odor. Here, we suggest that the efficacy of the floral blend in different environments may be an important selective force shaping differences in pollinator olfactory receptor expression and underlying neural mechanisms that mediate flower visitation and plant reproductive isolation.
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Affiliation(s)
- Claire Rusch
- Department of Biology, University of Washington, Seattle, WA 98195, United States
| | - Geoffrey T Broadhead
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, United States
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, United States.
| | - Jeffrey A Riffell
- Department of Biology, University of Washington, Seattle, WA 98195, United States.
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28
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Maleszka R. Epigenetic code and insect behavioural plasticity. CURRENT OPINION IN INSECT SCIENCE 2016; 15:45-52. [PMID: 27436731 DOI: 10.1016/j.cois.2016.03.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 06/06/2023]
Abstract
Although the nature of the genetic control of adaptive behaviours in insects is a major unresolved problem it is now understood that epigenetic mechanisms, bound by genetic constraints, are prime drivers of brain plasticity arising from both developmental and experience-dependent events. With the recent advancements in methylomics and emerging analyses of histones and non-protein-coding RNAs, insect epigenetics is well positioned to ask more direct questions and importantly, address them experimentally. To achieve rapid progress, insect epigenetics needs to focus on mechanistic explanations of epigenomic dynamics and move beyond low-depth genome-wide analyses to cell-type specific epigenomics. One topic of a high priority is the impact of sequence variants on generating differential methylation patterns and their contribution to behavioural plasticity.
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Affiliation(s)
- Ryszard Maleszka
- The Australian National University, Canberra, ACT 2601, Australia.
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29
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30
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Robinson KL, Tohidi-Esfahani D, Ponton F, Simpson SJ, Sword GA, Lo N. Alternative migratory locust phenotypes are associated with differences in the expression of genes encoding the methylation machinery. INSECT MOLECULAR BIOLOGY 2016; 25:105-115. [PMID: 26612460 DOI: 10.1111/imb.12203] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Despite the importance of locust density-dependent polyphenism as a model system for understanding phenotypic plasticity, there is still much to be learnt about its underlying molecular control. Here we describe the first investigation into the expression of genes encoding the DNA methylation machinery in the migratory locust (Locusta migratoria). We show that the alternative solitarious and gregarious phenotypic states induced by different locust rearing densities are associated with significant differences in the expression of the target genes DNA methyltransferase 1, DNA methyltransferase 2 and methyl-CpG-binding domain protein 2/3. This variation was most pronounced in the embryos of solitarious vs. gregarious mothers. We mapped the embryonic methylation profiles of several intragenic regions and a Long Interspersed Nuclear Element (LINE), each of which is known to be differentially expressed between alternative locust phenotypes or has been directly implicated in phase change. LmI and three genes, adenyl cyclase-associated binding protein 2, choline kinase alpha-like and henna, were methylated. Our results set the stage for future studies investigating the specific role of DNA methylation in the maternal transfer of migratory locust phase polyphenism.
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Affiliation(s)
- K L Robinson
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
| | - D Tohidi-Esfahani
- ANU College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, Australia
| | - F Ponton
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
- Charles Perkins Centre, The University of Sydney, NSW, Australia
- Department of Biological Sciences, Macquarie University, North Ryde NSW, Australia
| | - S J Simpson
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
- Charles Perkins Centre, The University of Sydney, NSW, Australia
| | - G A Sword
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - N Lo
- School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia
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31
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Lockett GA, Almond EJ, Huggins TJ, Parker JD, Bourke AFG. Gene expression differences in relation to age and social environment in queen and worker bumble bees. Exp Gerontol 2016; 77:52-61. [PMID: 26883339 DOI: 10.1016/j.exger.2016.02.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/24/2016] [Accepted: 02/12/2016] [Indexed: 02/03/2023]
Abstract
Eusocial insects provide special insights into the genetic pathways influencing aging because of their long-lived queens and flexible aging schedules. Using qRT-PCR in the primitively eusocial bumble bee Bombus terrestris (Linnaeus), we investigated expression levels of four candidate genes associated with taxonomically widespread age-related pathways (coenzyme Q biosynthesis protein 7, COQ7; DNA methyltransferase 3, Dnmt3; foraging, for; and vitellogenin, vg). In Experiment 1, we tested how expression changes with queen relative age and productivity. We found a significant age-related increase in COQ7 expression in queen ovary. In brain, all four genes showed higher expression with increasing female (queen plus worker) production, with this relationship strengthening as queen age increased, suggesting a link with the positive association of fecundity and longevity found in eusocial insect queens. In Experiment 2, we tested effects of relative age and social environment (worker removal) in foundress queens and effects of age and reproductive status in workers. In this experiment, workerless queens showed significantly higher for expression in brain, as predicted if downregulation of for is associated with the cessation of foraging by foundress queens following worker emergence. Workers showed a significant age-related increase in Dnmt3 expression in fat body, suggesting a novel association between aging and methylation in B. terrestris. Ovary activation was associated with significantly higher vg expression in fat body and, in younger workers, in brain, consistent with vitellogenin's ancestral role in regulating egg production. Overall, our findings reveal a mixture of novel and conserved features in age-related genetic pathways under primitive eusociality.
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Affiliation(s)
- Gabrielle A Lockett
- School of Biological Sciences, University of Southampton, Life Sciences Building, Highfield Campus, Southampton SO17 1BJ, UK
| | - Edward J Almond
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Timothy J Huggins
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Joel D Parker
- School of Biological Sciences, University of Southampton, Life Sciences Building, Highfield Campus, Southampton SO17 1BJ, UK
| | - Andrew F G Bourke
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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32
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Dabe EC, Sanford RS, Kohn AB, Bobkova Y, Moroz LL. DNA Methylation in Basal Metazoans: Insights from Ctenophores. Integr Comp Biol 2015; 55:1096-110. [PMID: 26173712 PMCID: PMC4817592 DOI: 10.1093/icb/icv086] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Epigenetic modifications control gene expression without altering the primary DNA sequence. However, little is known about DNA methylation in invertebrates and its evolution. Here, we characterize two types of genomic DNA methylation in ctenophores, 5-methyl cytosine (5-mC) and the unconventional form of methylation 6-methyl adenine (6-mA). Using both bisulfite sequencing and an ELISA-based colorimetric assay, we experimentally confirmed the presence of 5-mC DNA methylation in ctenophores. In contrast to other invertebrates studied, Mnemiopsis leidyi has lower levels of genome-wide 5-mC methylation, but higher levels of 5-mC methylation in promoters when compared with gene bodies. Phylogenetic analysis showed that ctenophores have distinct forms of DNA methyltransferase 1 (DNMT1); the zf-CXXC domain type, which localized DNMT1 to CpG sites, and is a metazoan specific innovation. We also show that ctenophores encode the full repertoire of putative enzymes for 6-mA DNA methylation, and these genes are expressed in the aboral organ of Mnemiopsis. Using an ELISA-based colorimetric assay, we experimentally confirmed the presence of 6-mA methylation in the genomes of three different species of ctenophores, M. leidyi, Beroe abyssicola, and Pleurobrachia bachei. The functional role of this novel epigenomic mark is currently unknown. In summary, despite their compact genomes, there is a wide variety of epigenomic mechanisms employed by basal metazoans that provide novel insights into the evolutionary origins of biological novelties.
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Affiliation(s)
- Emily C Dabe
- *The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St Augustine, FL 32080, USA; Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
| | - Rachel S Sanford
- *The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St Augustine, FL 32080, USA; Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
| | - Andrea B Kohn
- *The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St Augustine, FL 32080, USA
| | - Yelena Bobkova
- *The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St Augustine, FL 32080, USA
| | - Leonid L Moroz
- *The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St Augustine, FL 32080, USA; Department of Neuroscience and McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
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33
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Panikar CS, Rajpathak SN, Abhyankar V, Deshmukh S, Deobagkar DD. Presence of DNA methyltransferase activity and CpC methylation in Drosophila melanogaster. Mol Biol Rep 2015; 42:1615-21. [PMID: 26547851 DOI: 10.1007/s11033-015-3931-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/03/2015] [Indexed: 12/30/2022]
Abstract
Drosophila melanogaster lacks DNMT1/DNMT3 based methylation machinery. Despite recent reports confirming the presence of low DNA methylation in Drosophila; little is known about the methyltransferase. Therefore, in this study, we have aimed to investigate the possible functioning of DNA methyltransferase in Drosophila. The 14 K oligo microarray slide was incubated with native cell extract from adult Drosophila to check the presence of the methyltransferase activity. After incubation under appropriate conditions, the methylated oligo sequences were identified by the binding of anti 5-methylcytosine monoclonal antibody. The antibody bound to the methylated oligos was detected using Cy3 labeled secondary antibody. Methylation sensitive restriction enzyme mediated PCR was used to assess the methylation at a few selected loci identified on the array. It could be seen that a few of the total oligos got methylated under the assay conditions. Analysis of methylated oligo sequences provides evidence for the presence of de novo methyltransferase activity and allows identification of its sequence specificity in adult Drosophila. With the help of methylation sensitive enzymes we could detect presence of CpC methylation in the selected genomic regions. This study reports presence of an active DNA methyltransferase in adult Drosophila, which exhibits sequence specificity confirmed by presence of asymmetric methylation at corresponding sites in the genomic DNA. It also provides an innovative approach to investigate methylation specificity of a native methyltransferase.
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Affiliation(s)
- Chitra S Panikar
- Molecular Biology Research Laboratory, Department of Zoology, Centre for Advanced Studies, University of Pune, Pune, 411007, India
| | - Shriram N Rajpathak
- Molecular Biology Research Laboratory, Department of Zoology, Centre for Advanced Studies, University of Pune, Pune, 411007, India
| | - Varada Abhyankar
- Molecular Biology Research Laboratory, Department of Zoology, Centre for Advanced Studies, University of Pune, Pune, 411007, India
| | - Saniya Deshmukh
- Molecular Biology Research Laboratory, Department of Zoology, Centre for Advanced Studies, University of Pune, Pune, 411007, India
| | - Deepti D Deobagkar
- Molecular Biology Research Laboratory, Department of Zoology, Centre for Advanced Studies, University of Pune, Pune, 411007, India. .,Bioinformatics Center, University of Pune, Pune, 411007, India.
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34
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Dnmts and Tet target memory-associated genes after appetitive olfactory training in honey bees. Sci Rep 2015; 5:16223. [PMID: 26531238 PMCID: PMC4632027 DOI: 10.1038/srep16223] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/08/2015] [Indexed: 11/09/2022] Open
Abstract
DNA methylation and demethylation are epigenetic mechanisms involved in memory formation. In honey bees DNA methyltransferase (Dnmt) function is necessary for long-term memory to be stimulus specific (i.e. to reduce generalization). So far, however, it remains elusive which genes are targeted and what the time-course of DNA methylation is during memory formation. Here, we analyse how DNA methylation affects memory retention, gene expression, and differential methylation in stimulus-specific olfactory long-term memory formation. Out of 30 memory-associated genes investigated here, 9 were upregulated following Dnmt inhibition in trained bees. These included Dnmt3 suggesting a negative feedback loop for DNA methylation. Within these genes also the DNA methylation pattern changed during the first 24 hours after training. Interestingly, this was accompanied by sequential activation of the DNA methylation machinery (i.e. Dnmts and Tet). In sum, memory formation involves a temporally complex epigenetic regulation of memory-associated genes that facilitates stimulus specific long-term memory in the honey bee.
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35
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Yang SX, Guo C, Zhang YK, Sun JT, Hong XY. Expression level and immunolocalization of de novo methyltransferase 3 protein (TuDNMT3) in adult females and males of the two-spotted spider mite, Tetranychus urticae. EXPERIMENTAL & APPLIED ACAROLOGY 2015; 67:381-392. [PMID: 26246190 DOI: 10.1007/s10493-015-9957-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/22/2015] [Indexed: 06/04/2023]
Abstract
DNA methylation is an epigenetic mechanism for regulating developmental and other important processes in eukaryotes. Several essential components of the DNA methylation machinery have been identified, such as DNA methyltransferases. In the two-spotted spider mite, Tetranychus urticae Koch, we have identified one DNA methyltransferase 3 gene (Tudnmt3) and tentatively investigated its potential role in adult females and males. Here, to better elucidate the functional role of Tudnmt3, its protein structure, expression and localization were subjected to more detailed analyses. Bioinformatic analyses clearly showed that the structure of TuDNMT3 was highly conserved, with several vital amino acid residues for the activation and stabilization of its confirmation. Western blot analyses revealed that this protein was expressed in both genders, with higher expression in adult females, which was inconsistent with the gene expression, suggesting translational regulation of Tudnmt3. Subsequent immunodetection provided supportive evidence for higher expression of the TuDNMT3 protein in adult females and indicated that this protein was generally localized in the cytoplasm and that its expression was predominantly confined to the genital region of spider mites, strengthening the hypothesis that de novo methylation mediated by Tudnmt3 in gonad development or gametogenesis has a different mechanism from maintenance methyltransferase.
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Affiliation(s)
- Si-Xia Yang
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Chao Guo
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yan-Kai Zhang
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Jing-Tao Sun
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xiao-Yue Hong
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China.
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36
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Wedd L, Kucharski R, Maleszka R. Differentially methylated obligatory epialleles modulate context-dependent LAM gene expression in the honeybee Apis mellifera. Epigenetics 2015; 11:1-10. [PMID: 26507253 DOI: 10.1080/15592294.2015.1107695] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Differential intragenic methylation in social insects has been hailed as a prime mover of environmentally driven organismal plasticity and even as evidence for genomic imprinting. However, very little experimental work has been done to test these ideas and to prove the validity of such claims. Here we analyze in detail differentially methylated obligatory epialleles of a conserved gene encoding lysosomal α-mannosidase (AmLAM) in the honeybee. We combined genotyping of progenies derived from colonies founded by single drone inseminated queens, ultra-deep allele-specific bisulfite DNA sequencing, and gene expression to reveal how sequence variants, DNA methylation, and transcription interrelate. We show that both methylated and non-methylated states of AmLAM follow Mendelian inheritance patterns and are strongly influenced by polymorphic changes in DNA. Increased methylation of a given allele correlates with higher levels of context-dependent AmLAM expression and appears to affect the transcription of an antisense long noncoding RNA. No evidence of allelic imbalance or imprinting involved in this process has been found. Our data suggest that by generating alternate methylation states that affect gene expression, sequence variants provide organisms with a high level of epigenetic flexibility that can be used to select appropriate responses in various contexts. This study represents the first effort to integrate DNA sequence variants, gene expression, and methylation in a social insect to advance our understanding of their relationships in the context of causality.
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Affiliation(s)
| | | | - Ryszard Maleszka
- a Research School of Biology, The Australian National University , Canberra , ACT , Australia
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37
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Zhang J, Xing Y, Li Y, Yin C, Ge C, Li F. DNA methyltransferases have an essential role in female fecundity in brown planthopper, Nilaparvata lugens. Biochem Biophys Res Commun 2015; 464:83-8. [DOI: 10.1016/j.bbrc.2015.05.114] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 05/30/2015] [Indexed: 12/19/2022]
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38
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Morris MJ, Monteggia LM. Role of DNA methylation and the DNA methyltransferases in learning and memory. DIALOGUES IN CLINICAL NEUROSCIENCE 2015. [PMID: 25364286 PMCID: PMC4214178 DOI: 10.31887/dcns.2014.16.3/mmorris] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Dynamic regulation of chromatin structure in postmitotic neurons plays an important role in learning and memory. Methylation of cytosine nucleotides has historically been considered the strongest and least modifiable of epigenetic marks. Accumulating recent data suggest that rapid and dynamic methylation and demethylation of specific genes in the brain may play a fundamental role in learning, memory formation, and behavioral plasticity. The current review focuses on the emergence of data that support the role of DNA methylation and demethylation, and its molecular mediators in memory formation.
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Affiliation(s)
- Michael J Morris
- Department of Biological Sciences, University of Michigan-Dearborn, Dearborn, Michigan, USA
| | - Lisa M Monteggia
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA
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39
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Galbraith DA, Yang X, Niño EL, Yi S, Grozinger C. Parallel epigenomic and transcriptomic responses to viral infection in honey bees (Apis mellifera). PLoS Pathog 2015; 11:e1004713. [PMID: 25811620 PMCID: PMC4374888 DOI: 10.1371/journal.ppat.1004713] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 01/28/2015] [Indexed: 01/07/2023] Open
Abstract
Populations of honey bees are declining throughout the world, with US beekeepers losing 30% of their colonies each winter. Though multiple factors are driving these colony losses, it is increasingly clear that viruses play a major role. However, information about the molecular mechanisms mediating antiviral immunity in honey bees is surprisingly limited. Here, we examined the transcriptional and epigenetic (DNA methylation) responses to viral infection in honey bee workers. One-day old worker honey bees were fed solutions containing Israeli Acute Paralysis Virus (IAPV), a virus which causes muscle paralysis and death and has previously been associated with colony loss. Uninfected control and infected, symptomatic bees were collected within 20-24 hours after infection. Worker fat bodies, the primary tissue involved in metabolism, detoxification and immune responses, were collected for analysis. We performed transcriptome- and bisulfite-sequencing of the worker fat bodies to identify genome-wide gene expression and DNA methylation patterns associated with viral infection. There were 753 differentially expressed genes (FDR<0.05) in infected versus control bees, including several genes involved in epigenetic and antiviral pathways. DNA methylation status of 156 genes (FDR<0.1) changed significantly as a result of the infection, including those involved in antiviral responses in humans. There was no significant overlap between the significantly differentially expressed and significantly differentially methylated genes, and indeed, the genomic characteristics of these sets of genes were quite distinct. Our results indicate that honey bees have two distinct molecular pathways, mediated by transcription and methylation, that modulate protein levels and/or function in response to viral infections.
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Affiliation(s)
- David A. Galbraith
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Xingyu Yang
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Elina Lastro Niño
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Soojin Yi
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Christina Grozinger
- Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America
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40
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Nikitin V, Solntseva S, Nikitin P, Kozyrev S. The role of DNA methylation in the mechanisms of memory reconsolidation and development of amnesia. Behav Brain Res 2015; 279:148-54. [DOI: 10.1016/j.bbr.2014.11.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/09/2014] [Accepted: 11/12/2014] [Indexed: 12/22/2022]
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41
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Yan H, Bonasio R, Simola DF, Liebig J, Berger SL, Reinberg D. DNA methylation in social insects: how epigenetics can control behavior and longevity. ANNUAL REVIEW OF ENTOMOLOGY 2015; 60:435-52. [PMID: 25341091 DOI: 10.1146/annurev-ento-010814-020803] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In eusocial insects, genetically identical individuals can exhibit striking differences in behavior and longevity. The molecular basis of such phenotypic plasticity is of great interest to the scientific community. DNA methylation, as well as other epigenetic signals, plays an important role in modulating gene expression and can therefore establish, sustain, and alter organism-level phenotypes, including behavior and life span. Unlike DNA methylation in mammals, DNA methylation in insects, including eusocial insects, is enriched in gene bodies of actively expressed genes. Recent investigations have revealed the important role of gene body methylation in regulating gene expression in response to intrinsic and environmental factors. In this review, we summarize recent advances in DNA methylation research and discuss its significance in our understanding of the epigenetic underpinnings of behavior and longevity.
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Affiliation(s)
- Hua Yan
- Department of Biochemistry and Molecular Pharmacology and
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42
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Strachecka A, Krauze M, Olszewski K, Borsuk G, Paleolog J, Merska M, Chobotow J, Bajda M, Grzywnowicz K. Unexpectedly strong effect of caffeine on the vitality of western honeybees (Apis mellifera). BIOCHEMISTRY (MOSCOW) 2014; 79:1192-201. [DOI: 10.1134/s0006297914110066] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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43
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Yang SX, Guo C, Xu M, Sun JT, Hong XY. Sex-dependent activity of de novo methyltransferase 3 (Tudnmt3) in the two-spotted mite, Tetranychus urticae Koch. INSECT MOLECULAR BIOLOGY 2014; 23:743-753. [PMID: 25055993 DOI: 10.1111/imb.12120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
DNA methylation is an epigenetic mechanism for regulating developmental and other important processes in eukaryotes. Several components of the DNA methylation machinery have been identified, such as DNA methyltransferases. However, little is known about DNA methyltransferases in chelicerates, which is the second largest arthropod group. Epigenetics are expected to have a crucial role in the metabolism and development of this group. Here, we investigated the role of DNA methyltransferase 3 in the development of Tetranychus urticae Koch. In silico analyses clearly showed that this enzyme possesses the necessary conserved motifs for the catalytic activity of de novo methylation of DNA. Real-time PCR revealed that T. urticae de novo methyltransferase 3 (Tudnmt3) is expressed ubiquitously and throughout the life cycle of the two-spotted spider mite. However, the pattern of Tudnmt3 expression was sex-dependent during the adult stage. Whole in situ hybridization provided supportive evidence that Tudnmt3 is linked to the differentiation of the gonads in adult females and males. Methylation-sensitive amplification polymorphism analyses of 119 loci showed that the status of DNA methylation is partially different between adult females and males, raising the possibility that this sex-dependent DNA methylation pattern is mediated by different methylation activity of Tudnmt3.
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Affiliation(s)
- S-X Yang
- Department of Entomology, Nanjing Agricultural University, Nanjing, Jiangsu, China
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44
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Lockett GA, Patil VK, Soto-Ramírez N, Ziyab AH, Holloway JW, Karmaus W. Epigenomics and allergic disease. Epigenomics 2014; 5:685-99. [PMID: 24283882 DOI: 10.2217/epi.13.68] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Allergic disease development is affected by both genes and the environment, and epigenetic mechanisms are hypothesized to mediate these environmental effects. In this article, we discuss the link between the environment, DNA methylation and allergic disease, as well as questions of causality inherent to analyses of DNA methylation. From the practical side, we describe characteristics of allergic phenotypes and contrast different epidemiologic study designs used in epigenetic research. We examine methodological considerations, how best to conduct preprocessing and analysis of DNA methylation data sets, and the latest methods, technologies and discoveries in this rapidly advancing field. DNA methylation and other epigenetic marks are firmly entwined with allergic disease, a link that may hold the basis for future allergic disease diagnosis and treatment.
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Affiliation(s)
- Gabrielle A Lockett
- Human Development & Health, Faculty of Medicine, University of Southampton, Southampton, UK
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45
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Eisenhardt D. Molecular mechanisms underlying formation of long-term reward memories and extinction memories in the honeybee (Apis mellifera). ACTA ACUST UNITED AC 2014; 21:534-42. [PMID: 25225299 PMCID: PMC4175491 DOI: 10.1101/lm.033118.113] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The honeybee (Apis mellifera) has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a flower's characteristic features with a reward in a way that resembles olfactory appetitive classical conditioning, a learning paradigm that is used to study mechanisms underlying learning and memory formation in the honeybee. Due to a plethora of studies on appetitive classical conditioning and phenomena related to it, the honeybee is one of the best characterized invertebrate model organisms from a learning psychological point of view. Moreover, classical conditioning and associated behavioral phenomena are surprisingly similar in honeybees and vertebrates, suggesting a convergence of underlying neuronal processes, including the molecular mechanisms that contribute to them. Here I review current thinking on the molecular mechanisms underlying long-term memory (LTM) formation in honeybees following classical conditioning and extinction, demonstrating that an in-depth analysis of the molecular mechanisms of classical conditioning in honeybees might add to our understanding of associative learning in honeybees and vertebrates.
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Affiliation(s)
- Dorothea Eisenhardt
- Department of Biology, Chemistry, Pharmacy, Institute of Biology, Neurobiology, Freie Universität Berlin, 14195 Berlin, Germany
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46
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Pamir E, Szyszka P, Scheiner R, Nawrot MP. Rapid learning dynamics in individual honeybees during classical conditioning. Front Behav Neurosci 2014; 8:313. [PMID: 25309366 PMCID: PMC4164006 DOI: 10.3389/fnbeh.2014.00313] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 08/26/2014] [Indexed: 01/08/2023] Open
Abstract
Associative learning in insects has been studied extensively by a multitude of classical conditioning protocols. However, so far little emphasis has been put on the dynamics of learning in individuals. The honeybee is a well-established animal model for learning and memory. We here studied associative learning as expressed in individual behavior based on a large collection of data on olfactory classical conditioning (25 datasets, 3298 animals). We show that the group-averaged learning curve and memory retention score confound three attributes of individual learning: the ability or inability to learn a given task, the generally fast acquisition of a conditioned response (CR) in learners, and the high stability of the CR during consecutive training and memory retention trials. We reassessed the prevailing view that more training results in better memory performance and found that 24 h memory retention can be indistinguishable after single-trial and multiple-trial conditioning in individuals. We explain how inter-individual differences in learning can be accommodated within the Rescorla–Wagner theory of associative learning. In both data-analysis and modeling we demonstrate how the conflict between population-level and single-animal perspectives on learning and memory can be disentangled.
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Affiliation(s)
- Evren Pamir
- Bernstein Center for Computational Neuroscience Berlin, Germany ; Neuroinformatics and Theoretical Neuroscience, Institute of Biology, Freie Universität Berlin Germany ; Department Genetics of Learning and Memory, Leibniz Institute for Neurobiology Magdeburg, Germany
| | - Paul Szyszka
- Department of Biology, University of Konstanz Konstanz, Germany
| | - Ricarda Scheiner
- Department of Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg Würzburg, Germany
| | - Martin P Nawrot
- Bernstein Center for Computational Neuroscience Berlin, Germany ; Neuroinformatics and Theoretical Neuroscience, Institute of Biology, Freie Universität Berlin Germany
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47
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Bronfman ZZ, Ginsburg S, Jablonka E. Shaping the learning curve: epigenetic dynamics in neural plasticity. Front Integr Neurosci 2014; 8:55. [PMID: 25071483 PMCID: PMC4083220 DOI: 10.3389/fnint.2014.00055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 06/18/2014] [Indexed: 12/22/2022] Open
Abstract
A key characteristic of learning and neural plasticity is state-dependent acquisition dynamics reflected by the non-linear learning curve that links increase in learning with practice. Here we propose that the manner by which epigenetic states of individual cells change during learning contributes to the shape of the neural and behavioral learning curve. We base our suggestion on recent studies showing that epigenetic mechanisms such as DNA methylation, histone acetylation, and RNA-mediated gene regulation are intimately involved in the establishment and maintenance of long-term neural plasticity, reflecting specific learning-histories and influencing future learning. Our model, which is the first to suggest a dynamic molecular account of the shape of the learning curve, leads to several testable predictions regarding the link between epigenetic dynamics at the promoter, gene-network, and neural-network levels. This perspective opens up new avenues for therapeutic interventions in neurological pathologies.
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Affiliation(s)
- Zohar Z Bronfman
- The Cohn Institute for the History and Philosophy of Science and Ideas, Faculty of Humanities, Tel-Aviv University Tel-Aviv, Israel ; School of Psychology, Faculty of Social Science, Tel-Aviv University Tel-Aviv, Israel
| | - Simona Ginsburg
- Natural Science Department, The Open University of Israel Raanana, Israel
| | - Eva Jablonka
- The Cohn Institute for the History and Philosophy of Science and Ideas, Faculty of Humanities, Tel-Aviv University Tel-Aviv, Israel
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48
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Welch M, Lister R. Epigenomics and the control of fate, form and function in social insects. CURRENT OPINION IN INSECT SCIENCE 2014; 1:31-38. [PMID: 32846727 DOI: 10.1016/j.cois.2014.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 06/11/2023]
Abstract
Phenotypic plasticity is central to the success of social insects. The ability to form functionally and behaviourally diverse phenotypes from a common genome enables synthesis of highly specialised castes that carry out unique roles essential for colony survival. There is accumulating evidence that the epigenome may underlie some of this diversity in social insects. Here we discuss recent research into the role of epigenomic control of behavioural and developmental caste determination in social insects. Furthermore we suggest future strategies for unravelling the complex mechanisms by which the epigenome may shape these diverse societies.
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Affiliation(s)
- Mat Welch
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, WA 6009, Australia; Centre for Integrative Bee Research, The University of Western Australia, Perth, WA 6009, Australia
| | - Ryan Lister
- Australian Research Council Centre of Excellence in Plant Energy Biology, The University of Western Australia, Perth, WA 6009, Australia.
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49
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Contrasting Effects of Histone Deacetylase Inhibitors on Reward and Aversive Olfactory Memories in the Honey Bee. INSECTS 2014; 5:377-98. [PMID: 26462690 PMCID: PMC4592598 DOI: 10.3390/insects5020377] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 04/12/2014] [Accepted: 05/19/2014] [Indexed: 11/17/2022]
Abstract
Much of what we have learnt from rodent models about the essential role of epigenetic processes in brain plasticity has made use of aversive learning, yet the role of histone acetylation in aversive memory in the honey bee, a popular invertebrate model for both memory and epigenetics, was previously unknown. We examined the effects of histone deacetylase (HDAC) inhibition on both aversive and reward olfactory associative learning in a discrimination proboscis extension reflex (PER) assay. We report that treatment with the HDAC inhibitors APHA compound 8 (C8), phenylbutyrate (PB) or sodium butyrate (NaB) impaired discrimination memory due to impairment of aversive memory in a dose-dependent manner, while simultaneously having no effect on reward memory. Treatment with C8 1 h before training, 1 h after training or 1 h before testing, impaired aversive but not reward memory at test. C8 treatment 1 h before training also improved aversive but not reward learning during training. PB treatment only impaired aversive memory at test when administered 1 h after training, suggesting an effect on memory consolidation specifically. Specific impairment of aversive memory (but not reward memory) by HDAC inhibiting compounds was robust, reproducible, occurred following treatment with three drugs targeting the same mechanism, and is likely to be genuinely due to alterations to memory as sucrose sensitivity and locomotion were unaffected by HDAC inhibitor treatment. This pharmacological dissection of memory highlights the involvement of histone acetylation in aversive memory in the honey bee, and expands our knowledge of epigenetic control of neural plasticity in invertebrates.
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Junca P, Carcaud J, Moulin S, Garnery L, Sandoz JC. Genotypic influence on aversive conditioning in honeybees, using a novel thermal reinforcement procedure. PLoS One 2014; 9:e97333. [PMID: 24828422 PMCID: PMC4020857 DOI: 10.1371/journal.pone.0097333] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 04/17/2014] [Indexed: 11/22/2022] Open
Abstract
In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera) is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER), bees learn to associate an odor (conditioned stimulus - CS) with an electric shock (unconditioned stimulus - US). This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee’s body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive.
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Affiliation(s)
- Pierre Junca
- Evolution, Genomes et Speciation Lab (LEGS – UPR 9034), CNRS, Gif-sur-Yvette, France
| | - Julie Carcaud
- Evolution, Genomes et Speciation Lab (LEGS – UPR 9034), CNRS, Gif-sur-Yvette, France
| | - Sibyle Moulin
- Evolution, Genomes et Speciation Lab (LEGS – UPR 9034), CNRS, Gif-sur-Yvette, France
| | - Lionel Garnery
- Evolution, Genomes et Speciation Lab (LEGS – UPR 9034), CNRS, Gif-sur-Yvette, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes et Speciation Lab (LEGS – UPR 9034), CNRS, Gif-sur-Yvette, France
- * E-mail:
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