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Royle JW, Hurwood D, Sadowski P, Dudley KJ. Non-CG DNA methylation marks the transition from pupa to adult in Helicoverpa armigera. INSECT MOLECULAR BIOLOGY 2024; 33:493-502. [PMID: 38668923 DOI: 10.1111/imb.12917] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 04/10/2024] [Indexed: 08/20/2024]
Abstract
DNA methylation in insects is generally low in abundance, and its role is not well understood. It is often localised in protein coding regions and associated with the expression of 'housekeeping' genes. Few studies have explored DNA methylation dynamics during lifecycle stage transitions in holometabolous (metamorphosing) insects. Using targeted mass spectrometry, we have found a significant difference in global DNA methylation levels between larvae, pupae and adults of Helicoverpa armigera (Lepidoptera: Noctuidae) Hübner, a polyphagous pest of agricultural importance. Whole-genome bisulfite sequencing confirmed these observations and pointed to non-CG context being the primary explanation for the difference observed between pupa and adult. Non-CG methylation was enriched in genes specific to various signalling pathways (Hippo signalling, Hedgehog signalling and mitogen-activated protein kinase (MAPK) signalling) and ATP-dependent chromatin remodelling. Understanding the function of this epigenetic mark could be a target in future studies focusing on integrated pest management.
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Affiliation(s)
- Jack W Royle
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - David Hurwood
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Pawel Sadowski
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kevin J Dudley
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland, Australia
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2
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Huang X, Li Q, Xu Y, Li A, Wang S, Chen Y, Zhang C, Zhang X, Wang H, Lv C, Sun B, Li S, Kang L, Chen B. A neural m 6A pathway regulates behavioral aggregation in migratory locusts. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1242-1254. [PMID: 38478296 DOI: 10.1007/s11427-023-2476-1] [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: 08/12/2023] [Accepted: 10/07/2023] [Indexed: 06/07/2024]
Abstract
RNA N6-methyladenosine (m6A), as the most abundant modification of messenger RNA, can modulate insect behaviors, but its specific roles in aggregation behaviors remain unexplored. Here, we conducted a comprehensive molecular and physiological characterization of the individual components of the methyltransferase and demethylase in the migratory locust Locusta migratoria. Our results demonstrated that METTL3, METTL14 and ALKBH5 were dominantly expressed in the brain and exhibited remarkable responses to crowding or isolation. The individual knockdown of methyltransferases (i.e., METTL3 and METTL14) promoted locust movement and conspecific attraction, whereas ALKBH5 knockdown induced a behavioral shift toward the solitary phase. Furthermore, global transcriptome profiles revealed that m6A modification could regulate the orchestration of gene expression to fine tune the behavioral aggregation of locusts. In summary, our in vivo characterization of the m6A functions in migratory locusts clearly demonstrated the crucial roles of the m6A pathway in effectively modulating aggregation behaviors.
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Affiliation(s)
- Xianliang Huang
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China
| | - Qing Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanan Xu
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Ang Li
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shanzheng Wang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yusheng Chen
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chunrui Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xia Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hailin Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Cong Lv
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100101, China
| | - Baofa Sun
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shaoqin Li
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Le Kang
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China.
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Bing Chen
- School of Life Science, Institutes of Life Science and Green Development, Hebei University, Baoding, 071002, China.
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3
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De Fabrizio V, Trotta V, Pariti L, Radice RP, Martelli G. Preliminary characterization of biomolecular processes related to plasticity in Acyrthosiphonpisum. Heliyon 2024; 10:e23650. [PMID: 38187294 PMCID: PMC10770479 DOI: 10.1016/j.heliyon.2023.e23650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
Global warming strongly impacts many organisms' development, distribution and population structure. This problem has attracted the attention of many scientists to understand and study its actual effects, especially on insects influenced by environmental temperatures. Aphids are a model for studies of the genetics and physiology of stress. Aphids are characterized by parthenogenetic reproduction, which limits the effects of recombination on evolutionary processes, and have shown resistance to various biotic and abiotic stresses. This study was based on the hypothesis that aphids have optimized, over time, genetic mechanisms capable to give them plasticity through genome modifications mediated by transposition. To understand and evaluate the effects of heat stress, the expression levels of transposases and methylases were analyzed in mothers and daughters. Our results show that after four days from the thermal shock, methylation decreases in both mothers and daughters, while transposition significantly increases in daughters, thus generating gene variability, essential for adaptation.
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Affiliation(s)
- Vincenzo De Fabrizio
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Vincenzo Trotta
- School of Agricultural Forestry, Food and Environmental Sciences (SAFE), University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Luigi Pariti
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
| | - Rosa Paola Radice
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
- Bioinnova srls, Via ponte nove luci, 22, 85100, Potenza, Italy
| | - Giuseppe Martelli
- Department of Science, University of Basilicata, Viale dell’Ateneo Lucano, 10, 85100, Potenza, Italy
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4
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Kucharski R, Ellis N, Jurkowski TP, Hurd PJ, Maleszka R. The PWWP domain and the evolution of unique DNA methylation toolkits in Hymenoptera. iScience 2023; 26:108193. [PMID: 37920666 PMCID: PMC10618690 DOI: 10.1016/j.isci.2023.108193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/11/2023] [Accepted: 10/10/2023] [Indexed: 11/04/2023] Open
Abstract
DNMT3 in Hymenoptera has a unique duplication of the essential PWWP domain. Using GST-tagged PWWP fusion proteins and histone arrays we show that these domains have gained new properties and represent the first case of PWWP domains binding to H3K27 chromatin modifications, including H3K27me3, a key modification that is important during development. Phylogenetic analyses of 107 genomes indicate that the duplicated PWWP domains separated into two sister clades, and their distinct binding capacities are supported by 3D modeling. Other features of this unique DNA methylation system include variable copies, losses, and duplications of DNMT1 and DNMT3, and combinatorial generations of DNMT3 isoforms including variants missing the catalytic domain. Some of these losses and duplications of are found only in parasitic wasps. We discuss our findings in the context of the crosstalk between DNA methylation and histone methylation, and the expanded potential of epigenomic modifications in Hymenoptera to drive evolutionary novelties.
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Affiliation(s)
- Robert Kucharski
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Nancy Ellis
- School of Biological & Behavioural Sciences, Queen Mary University of London, London, UK
| | | | - Paul J. Hurd
- School of Biological & Behavioural Sciences, Queen Mary University of London, London, UK
| | - Ryszard Maleszka
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
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5
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Sun D, Yu H, Li Q. Starvation-induced changes in sex ratio involve alterations in sex-related gene expression and methylation in Pacific oyster Crassostrea gigas. Comp Biochem Physiol B Biochem Mol Biol 2023; 267:110863. [PMID: 37164224 DOI: 10.1016/j.cbpb.2023.110863] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/06/2023] [Accepted: 05/06/2023] [Indexed: 05/12/2023]
Abstract
Aquatic animals are subject to varying degrees of starvation stress in their natural habitats due to food limitations. Consequently, starvation is a crucial environmental factor for sex determination in many species; however, limited research has been conducted on the effects of starvation on sex determination in shellfish. Here, four full sibling families of Pacific oysters were established and subjected to starvation stress. The results demonstrated that starvation caused the sex ratio (female to male) to change from 1:0.78 to 1:1.44 and resulted in a delay in gonadal development. Further studies revealed that the expression levels of DNA methylation-related genes Dnmt1 (DNA methyltransferase 1), Dnmt3a/b (DNA methyltransferase 3a/b) and Tet3 (tet methylcytosine dioxygenase 3) decreased under starvation stress. Conversely, the upregulation of Dmrt1 (doublesex and mab-3 related transcription factor 1), a gene typically associated with males, in females suggests that the increased proportion of males may be linked to starvation-induced high expression of this particular gene. In addition, the gene Dgkd (diacylglycerol kinase delta), which is involved in the regulation of second messenger protein kinase C, was differentially methylated between males and females, with the methylation level of this gene gradually increasing with male development, while the methylation level of this gene decreased under starvation stress. Correlation analysis of Dgkd methylation levels with expression levels showed a negative correlation between DNA methylation and gene expression. Finally dual fluorescence reporter experiments confirmed that DNA methylation suppressed Dgkd expression in vitro. In summary, the results suggest that starvation may regulate Dgkd gene expression through DNA methylation and thus affect Dmrt1 expression, thereby causing sex reversal in the Pacific oyster. The outcomes resolved how environmental factors are involved in sex reversal from an epigenetic perspective and provided a theoretical basis for sex control breeding in the Pacific oyster.
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Affiliation(s)
- Dongfang Sun
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Hong Yu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Qi Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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6
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Nicolis VF, Burger NFV, Botha AM. Whole-body transcriptome mining for candidate effectors from Diuraphis noxia. BMC Genomics 2022; 23:493. [PMID: 35799109 PMCID: PMC9264610 DOI: 10.1186/s12864-022-08712-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 06/20/2022] [Indexed: 11/30/2022] Open
Abstract
Background Proteins within aphid saliva play a crucial role as the molecular interface between aphids and their host plants. These salivary effectors modulate plant responses to favour aphid feeding and facilitate infestation. The identification of effectors from economically important pest species is central in understanding the molecular events during the aphid-plant interaction. The Russian wheat aphid (Diuraphis noxia, Kurdjumov) is one such pest that causes devastating losses to wheat and barley yields worldwide. Despite the severe threat to food security posed by D. noxia, the non-model nature of this pest and its host has hindered progress towards understanding this interaction. In this study, in the absence of a salivary gland transcriptome, whole-body transcriptomics data was mined to generate a candidate effector catalogue for D. noxia. Results Mining the transcriptome identified 725 transcripts encoding putatively secreted proteins amongst which were transcripts specific to D. noxia. Six of the seven examined D. noxia putative effectors, termed DnE’s (Diuraphis noxia effectors) exhibited salivary gland-specific expression. A comparative analysis between whole-body D. noxia transcriptome data versus the head and body transcriptomes from three other aphid species allowed us to define a catalogue of transcripts putatively upregulated in D. noxia head tissue. Five of these were selected for RT-qPCR confirmation, and were found to corroborate the differential expression predictions, with a further three confirmed to be highly expressed in D. noxia salivary gland tissue. Conclusions Determining a putative effector catalogue for D. noxia from whole-transcriptome data, particularly the identification of salivary-specific sequences potentially unique to D. noxia, provide the basis for future functional characterisation studies to gain further insight into this aphid-plant interaction. Furthermore, due to a lack of publicly available aphid salivary gland transcriptome data, the capacity to use comparative transcriptomics to compile a list of putative effector candidates from whole-body transcriptomics data will further the study of effectors in various aphid species. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08712-4.
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Affiliation(s)
- Vittorio F Nicolis
- Genetics Department, Stellenbosch University, Stellenbosch, 7600, South Africa
| | - N Francois V Burger
- Genetics Department, Stellenbosch University, Stellenbosch, 7600, South Africa
| | - Anna-Maria Botha
- Genetics Department, Stellenbosch University, Stellenbosch, 7600, South Africa.
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7
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Aigner GP, Pittl V, Fiechtner B, Egger B, Šrut M, Höckner M. Common mechanisms cannot explain time- and dose-dependent DNA methylation changes in earthworms exposed to cadmium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 812:151468. [PMID: 34742794 DOI: 10.1016/j.scitotenv.2021.151468] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/28/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
DNA hypermethylation caused by environmental pollutants like cadmium (Cd) has already been demonstrated in many invertebrates, including earthworms. However, the exact epigenetic mechanisms that drive this hypermethylation are largely unknown and even basic DNA methylation and demethylation processes are hardly characterized. Therefore, we used an important bioindicator, the earthworm Lumbricus terrestris, as a model organism to determine time- and dose-dependent effects of Cd on global and gene-specific DNA methylation and its underlying mechanisms. We revealed Cd-induced adenine and cytosine hypermethylation using specific antibodies in dot blots and found that the methylation level of adenine compared to cytosine changed even to a bigger extent. However, the levels of hydroxymethylated cytosine did not differ between treatment groups. General methylation and demethylation components like methyltransferases (DNMT1 and 3), and ten-eleven translocation (TET) genes were confirmed in L. terrestris by quantitative RealTime PCR. However, neither gene expression, nor DNMT and TET enzyme activity showed significant differences in the Cd exposure groups. Using bisulfite conversion and sequencing, gene body methylation (gbm) of metallothionein 2 (MT2), one of the most important detoxification proteins, was characterized. Cd-dependent changes in MT2 gbm could, however, not be correlated to MT2 gene activity evaluated by quantitative RealTime PCR. Future directions as well as missing links are discussed in the present study hinting towards the importance of studying epigenetic marks and mechanistic insights in a broad variety of species to deepen our knowledge on the effects of changing environmental conditions.
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Affiliation(s)
- Gerhard P Aigner
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Verena Pittl
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Birgit Fiechtner
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Bernhard Egger
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Maja Šrut
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Martina Höckner
- University of Innsbruck, Institute of Zoology, Center for Molecular Biosciences Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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8
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Aigner GP, Nenning P, Fiechtner B, Šrut M, Höckner M. DNA Methylation and Detoxification in the Earthworm Lumbricus terrestris Exposed to Cadmium and the DNA Demethylation Agent 5-aza-2'-deoxycytidine. TOXICS 2022; 10:100. [PMID: 35202286 PMCID: PMC8879108 DOI: 10.3390/toxics10020100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 01/27/2023]
Abstract
Earthworms are well-established model organisms for testing the effects of heavy metal pollution. How DNA methylation affects cadmium (Cd) detoxification processes such as the expression of metallothionein 2 (MT2), however, is largely unknown. We therefore exposed Lumbricus terrestris to 200 mg concentrations of Cd and 5-aza-2'-deoxycytidine (Aza), a demethylating agent, and sampled tissue and coelomocytes, cells of the innate immune system, for 48 h. MT2 transcription significantly increased in the Cd- and Cd-Aza-treated groups. In tissue samples, a significant decrease in MT2 in the Aza-treated group was detected, showing that Aza treatment inhibits basal MT2 gene activity but has no effect on Cd-induced MT2 levels. Although Cd repressed the gene expression of DNA-(cytosine-5)-methyltransferase-1 (DNMT1), which is responsible for maintaining DNA methylation, DNMT activity was unchanged, meaning that methylation maintenance was not affected in coelomocytes. The treatment did not influence DNMT3, which mediates de novo methylation, TET gene expression, which orchestrates demethylation, and global levels of hydroxymethylcytosine (5hmC), a product of the demethylation process. Taken together, this study indicates that Aza inhibits basal gene activity, in contrast to Cd-induced MT2 gene expression, but does not affect global DNA methylation. We therefore conclude that Cd detoxification based on the induction of MT2 does not relate to DNA methylation changes.
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Affiliation(s)
| | | | | | | | - Martina Höckner
- Department of Zoology, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria; (G.P.A.); (P.N.); (B.F.); (M.Š.)
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9
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Duncan EJ, Cunningham CB, Dearden PK. Phenotypic Plasticity: What Has DNA Methylation Got to Do with It? INSECTS 2022; 13:110. [PMID: 35206684 PMCID: PMC8878681 DOI: 10.3390/insects13020110] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/14/2022]
Abstract
How does one genome give rise to multiple, often markedly different, phenotypes in response to an environmental cue? This phenomenon, known as phenotypic plasticity, is common amongst plants and animals, but arguably the most striking examples are seen in insects. Well-known insect examples include seasonal morphs of butterfly wing patterns, sexual and asexual reproduction in aphids, and queen and worker castes of eusocial insects. Ultimately, we need to understand how phenotypic plasticity works at a mechanistic level; how do environmental signals alter gene expression, and how are changes in gene expression translated into novel morphology, physiology and behaviour? Understanding how plasticity works is of major interest in evolutionary-developmental biology and may have implications for understanding how insects respond to global change. It has been proposed that epigenetic mechanisms, specifically DNA methylation, are the key link between environmental cues and changes in gene expression. Here, we review the available evidence on the function of DNA methylation of insects, the possible role(s) for DNA methylation in phenotypic plasticity and also highlight key outstanding questions in this field as well as new experimental approaches to address these questions.
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Affiliation(s)
- Elizabeth J. Duncan
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | | | - Peter K. Dearden
- Genomics Aotearoa and Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand
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10
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Botha AM. Fast developing Russian wheat aphid biotypes remains an unsolved enigma. CURRENT OPINION IN INSECT SCIENCE 2021; 45:42-52. [PMID: 33359167 DOI: 10.1016/j.cois.2020.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/05/2020] [Accepted: 12/07/2020] [Indexed: 06/12/2023]
Abstract
Diuraphis noxia, commonly known as the Russian wheat aphid, is an economically important cereal pest species, highly invasive and reproduces mostly asexually. Remarkably, many new virulent populations continue to develop, despite the lack of genetic diversity in the aphid. Russian wheat aphid is a phloem feeder and is therefore engaged in a continuous arms battle with its cereal host, with the acquisition of virulence central to the breakdown of host resistance. In the review, most attention is given to recent topics about mechanisms and strategies whereby the aphid acquires virulence against its host, with special reference given to the role of noncoding RNA elements, bacteria, and the epigenetic pathway in possibly directing virulence.
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Affiliation(s)
- Anna-Maria Botha
- Genetics Department, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch 7601, South Africa.
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Tolmay VL, Sydenham SL, Sikhakhane TN, Nhlapho BN, Tsilo TJ. Elusive Diagnostic Markers for Russian Wheat Aphid Resistance in Bread Wheat: Deliberating and Reviewing the Status Quo. Int J Mol Sci 2020; 21:ijms21218271. [PMID: 33158282 PMCID: PMC7663459 DOI: 10.3390/ijms21218271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/13/2022] Open
Abstract
Russian wheat aphid, Diuraphis noxia (Kurdjumov), is a severe pest of wheat, Triticum aestivum L., throughout the world. Resistant cultivars are viewed as the most economical and environmentally viable control available. Studies to identify molecular markers to facilitate resistance breeding started in the 1990s, and still continue. This paper reviews and discusses the literature pertaining to the D. noxia R-genes on chromosome 7D, and markers reported to be associated with them. Individual plants with known phenotypes from a panel of South African wheat accessions are used as examples. Despite significant inputs from various research groups over many years, diagnostic markers for resistance to D. noxia remain elusive. Factors that may have impeded critical investigation, thus blurring the accumulation of a coherent body of information applicable to Dn resistance, are discussed. This review calls for a more fastidious approach to the interpretation of results, especially considering the growing evidence pointing to the complex regulation of aphid resistance response pathways in plants. Appropriate reflection on prior studies, together with emerging knowledge regarding the complexity and specificity of the D. noxia–wheat resistance interaction, should enable scientists to address the challenges of protecting wheat against this pest in future.
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Affiliation(s)
- Vicki L. Tolmay
- Agricultural Research Council, Small Grain, Private Bag X29, Bethlehem 9700, South Africa; (S.L.S.); (T.N.S.); (B.N.N.); (T.J.T.)
- Department of Life and Consumer Sciences, University of South Africa, Pretoria 0002, South Africa
- Correspondence:
| | - Scott L. Sydenham
- Agricultural Research Council, Small Grain, Private Bag X29, Bethlehem 9700, South Africa; (S.L.S.); (T.N.S.); (B.N.N.); (T.J.T.)
| | - Thandeka N. Sikhakhane
- Agricultural Research Council, Small Grain, Private Bag X29, Bethlehem 9700, South Africa; (S.L.S.); (T.N.S.); (B.N.N.); (T.J.T.)
- Department of Life and Consumer Sciences, University of South Africa, Pretoria 0002, South Africa
| | - Bongiwe N. Nhlapho
- Agricultural Research Council, Small Grain, Private Bag X29, Bethlehem 9700, South Africa; (S.L.S.); (T.N.S.); (B.N.N.); (T.J.T.)
| | - Toi J. Tsilo
- Agricultural Research Council, Small Grain, Private Bag X29, Bethlehem 9700, South Africa; (S.L.S.); (T.N.S.); (B.N.N.); (T.J.T.)
- Department of Life and Consumer Sciences, University of South Africa, Pretoria 0002, South Africa
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