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Brenman-Suttner D, Zayed A. An integrative genomic toolkit for studying the genetic, evolutionary, and molecular underpinnings of eusociality in insects. CURRENT OPINION IN INSECT SCIENCE 2024; 65:101231. [PMID: 38977215 DOI: 10.1016/j.cois.2024.101231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 06/26/2024] [Accepted: 07/02/2024] [Indexed: 07/10/2024]
Abstract
While genomic resources for social insects have vastly increased over the past two decades, we are still far from understanding the genetic and molecular basis of eusociality. Here, we briefly review three scientific advancements that, when integrated, can be highly synergistic for advancing our knowledge of the genetics and evolution of eusocial traits. Population genomics provides a natural way to quantify the strength of natural selection on coding and regulatory sequences, highlighting genes that have undergone adaptive evolution during the evolution or maintenance of eusociality. Genome-wide association studies (GWAS) can be used to characterize the complex genetic architecture underlying eusocial traits and identify candidate causal variants. Concurrently, CRISPR/Cas9 enables the precise manipulation of gene function to both validate genotype-phenotype associations and study the molecular biology underlying interesting traits. While each approach has its own advantages and disadvantages, which we discuss herein, we argue that their combination will ultimately help us better understand the genetics and evolution of eusocial behavior. Specifically, by triangulating across these three different approaches, researchers can directly identify and study loci that have a causal association with key phenotypes and have evidence of positive selection over the relevant timescales associated with the evolution and maintenance of eusociality in insects.
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Affiliation(s)
| | - Amro Zayed
- Department of Biology, York University, Toronto, Ontario, Canada.
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2
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Feng K, Jiang D, Luo J, Tang F. OfGNBP silencing enhances the toxicity of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki). PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 189:105306. [PMID: 36549813 DOI: 10.1016/j.pestbp.2022.105306] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/16/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
The immunity of insects plays a vital role in their survival. Our experiments found that lipopolysaccharide (LPS) and glucono-δ-lactone (GDL) could influence the virulence of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki) by affecting the immunity. Gram-negative binding proteins (GNBPs) are an important pattern recognition proteins that play a crucial role in the innate immune system. Therefore, two OfGNBPs were cloned in O. formosanus. The expression of OfGNBPs was significantly changed by LPS,SM1 and GDL, not prick. In addition, the immune-related gene expression, the phenoloxidase activity and antibacterial activity of donor termites and recipient termites were significantly induced by SM1. Furthermore, the knockdown of OfGNBP by RNA interference reduced not only individual immunity but also social immunity in O. formosanus, which increased the virulence of SM1 to O. formosanus. Importantly, dsOfGNBP alone also had good control effect on O. formosanus. In summary, we concluded that dsOfGNBPs are important termite immunosuppressants.
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Affiliation(s)
- Kai Feng
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Forestry, Nanjing Forestry University, Nanjing 210037, People's Republic of China
| | - Dabao Jiang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Forestry, Nanjing Forestry University, Nanjing 210037, People's Republic of China
| | - Jian Luo
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Forestry, Nanjing Forestry University, Nanjing 210037, People's Republic of China
| | - Fang Tang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Forestry, Nanjing Forestry University, Nanjing 210037, People's Republic of China.
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Zeng W, Shen D, Chen Y, Zhang S, Wu W, Li Z. A High Soldier Proportion Encouraged the Greater Antifungal Immunity in a Subterranean Termite. Front Physiol 2022; 13:906235. [PMID: 35733990 PMCID: PMC9207448 DOI: 10.3389/fphys.2022.906235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Indexed: 11/25/2022] Open
Abstract
Termites possess a mighty social immune system, serving as one of the key obstacles to controlling them biologically. However, the dynamic mechanism coordinating the social immunologic defense and caste distribution of the termites remains elusive. This study used the Coptotermes formosanus Shiraki and an entomopathogenic fungus as a host–pathogen system and experimentally manipulated a series of groups with different caste compositions of workers and soldiers. Then, the impact of demography on the behavior and innate immunity of termites was explored by analyzing the fungus susceptibility of the respective caste, efficiencies, and caste preferences of sanitary care, as well as the expression of the immune genes and phenoloxidase activity. Overall, to ensure the general health and survival of a group, the infected workers were found to sacrifice their survivorship for maintaining the soldier proportion of the group. If soldier proportion was limited within a threshold, both the survivorship of the workers and soldiers were not significantly affected by the infection. Correspondingly, the infected group with a higher proportion of soldiers stimulated the higher efficiency of a non-caste-biased sanitary care of the workers to the nestmate workers and soldiers. Moreover, the innate immunities of the infected workers were found to be more intensely upregulated in the group with higher soldier proportions. This suggested that the adjustable non-caste-biased sanitary care and innate immunity of the workers would contribute to the flexibility of the worker–soldier caste ratio in C. formosanus. This study, therefore, enhanced our understanding of the functional adaptation mechanism between pathogen-driven social immunity and the demography of the termites.
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Bulmer MS, Stefano AM. Termite eusociality and contrasting selective pressure on social and innate immunity. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03090-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Xia T, Zhang L, Sun G, Yang X, Zhang H. Genomic evidence of adaptive evolution in the reptilian SOCS gene family. PeerJ 2021; 9:e11677. [PMID: 34221740 PMCID: PMC8236234 DOI: 10.7717/peerj.11677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 06/04/2021] [Indexed: 11/20/2022] Open
Abstract
The suppressor of the cytokine signaling (SOCS) family of proteins play an essential role in inhibiting cytokine receptor signaling by regulating immune signal pathways. Although SOCS gene functions have been examined extensively, no comprehensive study has been performed on this gene family's molecular evolution in reptiles. In this study, we identified eight canonical SOCS genes using recently-published reptilian genomes. We used phylogenetic analysis to determine that the SOCS genes had highly conserved evolutionary dynamics that we classified into two types. We identified positive SOCS4 selection signals in whole reptile lineages and SOCS2 selection signals in the crocodilian lineage. Selective pressure analyses using the branch model and Z-test revealed that these genes were under different negative selection pressures compared to reptile lineages. We also concluded that the nature of selection pressure varies across different reptile lineages on SOCS3, and the crocodilian lineage has experienced rapid evolution. Our results may provide a theoretical foundation for further analyses of reptilian SOCS genes' functional and molecular mechanisms, as well as their roles in reptile growth and development.
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Affiliation(s)
- Tian Xia
- College of Life Science, Qufu Normal University, Qufu, Shandong, China
| | - Lei Zhang
- College of Life Science, Qufu Normal University, Qufu, Shandong, China
| | - Guolei Sun
- College of Life Science, Qufu Normal University, Qufu, Shandong, China
| | - Xiufeng Yang
- College of Life Science, Qufu Normal University, Qufu, Shandong, China
| | - Honghai Zhang
- College of Life Science, Qufu Normal University, Qufu, Shandong, China
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Costa-Leonardo AM, da Silva IB, Janei V, Poiani SB, Dos Santos-Pinto JRA, Esteves FG, Palma MS. Salivary glands in workers of Ruptitermes spp. (Blattaria, Isoptera, Termitidae, Apicotermitinae): a morphological and preoteomic approach. Cell Tissue Res 2021; 385:603-621. [PMID: 33961129 DOI: 10.1007/s00441-021-03469-w] [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: 11/18/2020] [Accepted: 04/27/2021] [Indexed: 10/21/2022]
Abstract
Salivary glands are omnipresent in termites and occur in all developmental stages and castes. They function to produce, store, and secrete compounds, ranging from a feeding function to defensive mechanisms. Here, we provide a complete morphological overview of the salivary glands in the soldierless species Ruptitermes reconditus and R. xanthochiton, and the first proteomic profile of the salivary glands in a Neotropical Apicotermitinae representative, R. reconditus. Salivary glands from both species were composed of several acini, roughly spherical structures composed of two types of central cells (type I and II) and peripheral parietal cells, as well as transporting ducts and two salivary reservoirs. Central cells were richly supplied with electron-lucent secretory vesicles and rough endoplasmic reticulum, a feature of protein-secreting cells. Parietal cells of Ruptitermes spp. had conspicuous characteristics such as electron-lucent secretory vesicles surrounded by mitochondria and well-developed microvilli. Moreover, different individuals showed variation in the secretory cycle of salivary acini, which may be related to polyethism. Ultrastructural analysis evidenced a high synthesis of secretion and also the occurrence of lysosomes and autophagic structures in central cells. Proteomic analysis of the salivary glands revealed 483 proteins divided into functional groups, highlighting toxins/defensins and compounds related to alarm communication and colony asepsis. Soldierless termites are quite successful, especially due to morphological adaptations of the workers, including unknown modifications of exocrine glands. Thus, according to our morphological and proteomic findings, we discuss the potential roles of the salivary gland secretion in different social aspects of the sampled species.
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Affiliation(s)
- Ana Maria Costa-Leonardo
- Laboratório de Cupins, Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil. .,Centro de Estudos de Insetos Sociais-CEIS, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil.
| | - Iago Bueno da Silva
- Laboratório de Cupins, Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Vanelize Janei
- Laboratório de Cupins, Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Silvana Beani Poiani
- Centro de Estudos de Insetos Sociais-CEIS, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - José Roberto Aparecido Dos Santos-Pinto
- Centro de Estudos de Insetos Sociais-CEIS, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Franciele Grego Esteves
- Centro de Estudos de Insetos Sociais-CEIS, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Mario Sérgio Palma
- Centro de Estudos de Insetos Sociais-CEIS, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
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Aguero CM, Eyer P, Martin JS, Bulmer MS, Vargo EL. Natural variation in colony inbreeding does not influence susceptibility to a fungal pathogen in a termite. Ecol Evol 2021; 11:3072-3083. [PMID: 33841768 PMCID: PMC8019025 DOI: 10.1002/ece3.7233] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 01/08/2021] [Accepted: 01/15/2021] [Indexed: 01/26/2023] Open
Abstract
Reduced genetic diversity through inbreeding can negatively affect pathogen resistance. This relationship becomes more complicated in social species, such as social insects, since the chance of disease transmission increases with the frequency of interactions among individuals. However, social insects may benefit from social immunity, whereby individual physiological defenses may be bolstered by collective-level immune responses, such as grooming or sharing of antimicrobial substance through trophallaxis. We set out to determine whether differences in genetic diversity between colonies of the subterranean termite, Reticulitermes flavipes, accounts for colony survival against pathogens. We sampled colonies throughout the United States (Texas, North Carolina, Maryland, and Massachusetts) and determined the level of inbreeding of each colony. To assess whether genetically diverse colonies were better able to survive exposure to diverse pathogens, we challenged groups of termite workers with two strains of a pathogenic fungus, one local strain present in the soil surrounding sampled colonies and another naïve strain, collected outside the range of this species. We found natural variation in the level of inbreeding between colonies, but this variation did not explain differences in susceptibility to either pathogen. Although the naïve strain was found to be more hazardous than the local strain, colony resistance was correlated between two strains, meaning that colonies had either relatively high or low susceptibility to both strains regardless of their inbreeding coefficient. Overall, our findings may reflect differential virulence between the strains, immune priming of the colonies via prior exposure to the local strain, or a coevolved resistance toward this strain. They also suggest that colony survival may rely more upon additional factors, such as different behavioral response thresholds or the influence of a specific genetic background, rather than the overall genetic diversity of the colony.
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Affiliation(s)
- Carlos M. Aguero
- Department of EntomologyTexas A&M UniversityCollege StationTXUSA
| | | | - Jason S. Martin
- Department of Biological SciencesTowson UniversityTowsonMDUSA
| | - Mark S. Bulmer
- Department of Biological SciencesTowson UniversityTowsonMDUSA
| | - Edward L. Vargo
- Department of EntomologyTexas A&M UniversityCollege StationTXUSA
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Harrison MC, Chernyshova AM, Thompson GJ. No obvious transcriptome-wide signature of indirect selection in termites. J Evol Biol 2020; 34:403-415. [PMID: 33290587 DOI: 10.1111/jeb.13749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/16/2020] [Accepted: 11/30/2020] [Indexed: 11/26/2022]
Abstract
The evolution of sterile helper castes in social insects implies selection on genes that underlie variation in this nonreproductive phenotype. These focal genes confer no direct fitness and are presumed to evolve through indirect fitness effects on the helper's reproducing relatives. This separation of a gene's phenotypic effect on one caste and its fitness effect on another suggests that genes for this and other forms of reproductive altruism are buffered from selection and will thus evolve closer to the neutral rate than genes directly selected for selfish reproduction. We test this hypothesis by comparing the strength of selection at loci associated in their expression with reproductive versus sterile castes in termites. Specifically, we gather caste-biased gene expression data from four termite transcriptomes and measure the global dN/dS ratio across gene sets and phylogenetic lineages. We find that the majority of examined orthologous gene groups show patterns of nucleotide substitution that are consistent with strong purifying selection and display little evidence for distinct signatures of direct versus indirect selection in reproductive and sterile castes. For one particular species (Reticulitermes flavipes), the strength of purifying selection is relaxed in a reproductive nymph-biased gene set, which opposes the nearly neutral idea. In other species, the synonymous rate (dS) alone was often found to be the highest in the sterile worker caste, suggesting a more subtle signature of indirect selection or an altogether different relationship between caste-biased expression and rates of molecular evolution.
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Affiliation(s)
- Mark C Harrison
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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Keshavarz M, Jo YH, Patnaik BB, Park KB, Ko HJ, Kim CE, Edosa TT, Lee YS, Han YS. TmRelish is required for regulating the antimicrobial responses to Escherichia coli and Staphylococcus aureus in Tenebrio molitor. Sci Rep 2020; 10:4258. [PMID: 32144366 PMCID: PMC7060202 DOI: 10.1038/s41598-020-61157-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 02/18/2020] [Indexed: 11/09/2022] Open
Abstract
Relish, a transcription factor, is a critical downstream component of the immune deficiency (Imd) pathway and regulates host defense against bacterial infection by mediating antimicrobial peptide (AMP) synthesis. Understanding the immunological function of the mealworm beetle, Tenebrio molitor Relish (TmRelish) will be instructive in understanding insect immunity. In the present study, full-length ORF of TmRelish was retrieved from T. molitor-expressed sequence tags and RNA-seq database. The predicted TmRelish amino acid sequence contained an N-terminal Rel-homology domain; an Ig-like, plexin, and transcription factor domain; ankyrin repeat motifs; a nuclear localization signal; and a C-terminal death domain and shared the highly conserved structure of the Relish proteins of other insect species. TmRelish mRNA was detected in all developmental stages of the insect; however, the highest levels were detected in the larval gut tissue and adult hemocytes. TmRelish mRNA level was upregulated in the fat body, hemocyte, and gut tissue 9 h after infection of T. molitor larvae by the gram-negative bacteria, Escherichia coli. Furthermore, TmRelish knockdown led to significantly higher mortality of the E. coli-infected larvae, and significantly lower mortality of larvae infected with Staphylococcus aureus or Candida albicans. To elucidate the possible cause of mortality, we measured AMP transcription in the fat body, hemocytes, gut, and Malpighian tubules (MTs) of T. molitor larvae. TmRelish knockdown suppressed the expression of nine AMP genes in the larval fat body and gut tissue during E. coli infection, suggesting that TmRelish positively regulates AMP expression in both immune-related tissues, in response to E. coli challenge. Furthermore, negative regulation of some AMPs by TmRelish in the MTs, gut and hemocytes in response to C. albicans infection suggests a crosstalk between the Toll and Imd pathways.
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Affiliation(s)
- Maryam Keshavarz
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Yong Hun Jo
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Bharat Bhusan Patnaik
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea.,Department of Biotechnology, Trident Academy of Technology (TAT), F2-A, Chandaka Industrial Estate, Chandrasekharpur, Bhubaneswar, Odisha, 751024, India
| | - Ki Beom Park
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Hye Jin Ko
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Chang Eun Kim
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Tariku Tesfaye Edosa
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Yong Seok Lee
- School of Biotechnology and Life Sciences, College of Natural Sciences, Soonchunhyang University, 22 Soonchunhyangro, Shinchang-myeon, Asan, Chungchungnam-do, 31538, South Korea
| | - Yeon Soo Han
- Department of Applied Biology, Institute of Environmentally Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea.
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Meusemann K, Korb J, Schughart M, Staubach F. No Evidence for Single-Copy Immune-Gene Specific Signals of Selection in Termites. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Costa-Leonardo AM, da Silva IB, Poiani SB, Dos Santos-Pinto JRA, Esteves FG, da Silva LHB, Palma MS. Proteomic-components provide insights into the defensive secretion in termite workers of the soldierless genus Ruptitermes. J Proteomics 2019; 213:103622. [PMID: 31863930 DOI: 10.1016/j.jprot.2019.103622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 12/03/2019] [Accepted: 12/14/2019] [Indexed: 12/11/2022]
Abstract
Termite soldiers constitute the defensive frontline of the colonies, despite workers also perform such tasks, especially within the Neotropical Apicotermitinae, in which all species are soldierless. Workers of the genus Ruptitermes display an extreme form of defense, characterized by body rupture and release of a sticky secretion. Previous observations suggested that such behavior may be advantageous against enemies, but the chemical composition of this secretion has been neglected. Here we firstly provide the proteomic profile of the defensive secretion of Ruptitermes reconditus and Ruptitermes pitan workers. Additionally, the mechanisms of action of this behavior was evaluated through different bioassays. A total of 446 proteins were identified in R. reconditus and 391 proteins in R. pitan, which were classified into: toxins, defensins and proteolytic enzymes; sticky components/ alarm communication; proteins related to detoxification processes; proteins involved in folding/conformation and post-translational modifications; housekeeping proteins; and uncharacterized/hypothetical proteins. According to the bioassays, the self-sacrifice is triggered by a physical stimulus, and the defensive secretion may cause immobility and death of the opponents. Assuming that termites are abundant in the tropics and therefore exposed to predators, suicidal behaviors seem to be advantageous, since the loss of an individual benefit the whole colony. SIGNIFICANCE: Although recent studies have reported the biochemical composition of different weapons in soldiered species of termites, such efforts had not been applied to sordierless taxa up until now. Thus, this is the first report of the defensive mechanisms in soldierless termite species based on proteomic analysis. The diversity of compounds, which included toxin-like and mucin-like proteins, reflect the mechanisms of action of the defensive secretion released by termite workers, which may cause immobility and death of the opponents. Our findings may contribute to the knowledge regarding the development of defensive strategies in termites, especially in groups which lost the soldier caste during the evolution.
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Affiliation(s)
- Ana Maria Costa-Leonardo
- Laboratório de Cupins, Departamento de Biologia, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP 13506-900, Brazil; Center for the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, Univ Estadual Paulista, UNESP, Rio Claro, São Paulo, Brazil.
| | - Iago Bueno da Silva
- Laboratório de Cupins, Departamento de Biologia, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP 13506-900, Brazil
| | - Silvana Beani Poiani
- Center for the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, Univ Estadual Paulista, UNESP, Rio Claro, São Paulo, Brazil
| | - José Roberto Aparecido Dos Santos-Pinto
- Center for the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, Univ Estadual Paulista, UNESP, Rio Claro, São Paulo, Brazil
| | - Franciele Grego Esteves
- Center for the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, Univ Estadual Paulista, UNESP, Rio Claro, São Paulo, Brazil
| | - Luiza Helena Bueno da Silva
- Laboratório de Cupins, Departamento de Biologia, Instituto de Biociências, Univ Estadual Paulista, UNESP, Campus Rio Claro, Avenida 24A, 1515, Bela Vista, Rio Claro, SP 13506-900, Brazil
| | - Mario Sergio Palma
- Center for the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, Univ Estadual Paulista, UNESP, Rio Claro, São Paulo, Brazil
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Worker Defensive Behavior Associated with Toxins in the Neotropical Termite Neocapritermes braziliensis (Blattaria, Isoptera, Termitidae, Termitinae). J Chem Ecol 2019; 45:755-767. [PMID: 31440960 DOI: 10.1007/s10886-019-01098-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 10/26/2022]
Abstract
Termite societies are abundant in the tropics, and are therefore exposed to multiple enemies and predators, especially during foraging activity. Soldiers constitute a specialized defensive caste, although workers also participate in this process, and even display suicidal behavior, which is the case with the species Neocapritermes braziliensis. Here we describe the morphology, mechanisms of action, and proteomics of the salivary weapon in workers of this species, which due to the autothysis of the salivary glands causes their body rupture, in turn releasing a defensive secretion, observed during aggressiveness bioassays. Salivary glands are paired, composed of two translucent reservoirs, ducts and a set of multicellular acini. Histological and ultrastructural techniques showed that acini are composed of two types of central cells, and small parietal cells located in the acinar periphery. Type I central cells were abundant and filled with a large amount of secretion, while type II central cells were scarce and presented smaller secretion. Parietal cells were often paired and devoid of secretion. The gel-free proteomic approach (shotgun) followed by mass spectrometry revealed 235 proteins in the defensive secretion, which were classified into functional groups: (i) toxins and defensins, (ii) folding/conformation and post-translational modifications, (iii) salivary gland detoxification, (iv) housekeeping proteins and (v) uncharacterized and hypothetical proteins. We highlight the occurrence of neurotoxins previously identified in arachnid venoms, which are novelties for termite biology, and contribute to the knowledge regarding the defense strategies developed by termite species from the Neotropical region.
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Salcedo-Porras N, Guarneri A, Oliveira PL, Lowenberger C. Rhodnius prolixus: Identification of missing components of the IMD immune signaling pathway and functional characterization of its role in eliminating bacteria. PLoS One 2019; 14:e0214794. [PMID: 30943246 PMCID: PMC6447187 DOI: 10.1371/journal.pone.0214794] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/20/2019] [Indexed: 12/16/2022] Open
Abstract
The innate immune system in insects is regulated by specific signalling pathways. Most immune related pathways were identified and characterized in holometabolous insects such as Drosophila melanogaster, and it was assumed they would be highly conserved in all insects. The hemimetabolous insect, Rhodnius prolixus, has served as a model to study basic insect physiology, but also is a major vector of the human parasite, Trypanosoma cruzi, that causes 10,000 deaths annually. The publication of the R. prolixus genome revealed that one of the main immune pathways, the Immune-deficiency pathway (IMD), was incomplete and probably non-functional, an observation shared with other hemimetabolous insects including the pea aphid (Acyrthosiphon pisum) and the bedbug (Cimex lectularius). It was proposed that the IMD pathway is inactive in R. prolixus as an adaptation to prevent eliminating beneficial symbiont gut bacteria. We used bioinformatic analyses based on reciprocal BLAST and HMM-profile searches to find orthologs for most of the "missing" elements of the IMD pathway and provide data that these are regulated in response to infection with Gram-negative bacteria. We used RNAi strategies to demonstrate the role of the IMD pathway in regulating the expression of specific antimicrobial peptides (AMPs) in the fat body of R. prolixus. The data indicate that the IMD pathway is present and active in R. prolixus, which opens up new avenues of research on R. prolixus-T. cruzi interactions.
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Affiliation(s)
- Nicolas Salcedo-Porras
- Centre for Cell Biology, Development, and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Alessandra Guarneri
- Instituto René Rachou, Avenida Augusto de Lima, Belo Horizonte, Minas Gerais, Brazil
| | - Pedro L. Oliveira
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundão, Rio de Janeiro, Brazil
| | - Carl Lowenberger
- Centre for Cell Biology, Development, and Disease, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
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14
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Souza RS, Gama MDVF, Schama R, Lima JBP, Diaz-Albiter HM, Genta FA. Biochemical and Functional Characterization of Glycoside Hydrolase Family 16 Genes in Aedes aegypti Larvae: Identification of the Major Digestive β-1,3-Glucanase. Front Physiol 2019; 10:122. [PMID: 30873040 PMCID: PMC6403176 DOI: 10.3389/fphys.2019.00122] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 01/31/2019] [Indexed: 12/13/2022] Open
Abstract
Insect β-1,3-glucanases belong to Glycoside Hydrolase Family 16 (GHF16) and are involved in digestion of detritus and plant hemicellulose. In this work, we investigated the role of GHF16 genes in Aedes aegypti larvae, due to their detritivore diet. Aedes aegypti genome has six genes belonging to GHF16 (Aae GH16.1 – Aae GH16.6), containing two to six exons. Sequence analysis suggests that five of these GHF16 sequences (Aae GH16.1, 2, 3, 5, and 6) contain the conserved catalytic residues of this family and correspond to glucanases. All genomes of Nematocera analyzed showed putative gene duplications corresponding to these sequences. Aae GH16.4 has no conserved catalytic residues and is probably a β-1,3-glucan binding protein involved in the activation of innate immune responses. Additionally, Ae. aegypti larvae contain significant β-1,3-glucanase activities in the head, gut and rest of body. These activities have optimum pH about 5–6 and molecular masses between 41 and 150 kDa. All GHF16 genes above showed different levels of expression in the larval head, gut or rest of the body. Knock-down of AeGH16.5 resulted in survival and pupation rates lower than controls (dsGFP and water treated). However, under stress conditions, severe mortalities were observed in AeGH16.1 and AeGH16.6 knocked-down larvae. Enzymatic assays of β-1,3-glucanase in AeGH16.5 silenced larvae exhibited lower activity in the gut and no change in the rest of the body. Chromatographic activity profiles from gut samples after GH16.5 silencing showed suppression of enzymatic activity, suggesting that this gene codes for the digestive larval β-1,3-glucanase of Ae. aegypti. This gene and enzyme are attractive targets for new control strategies, based on the impairment of normal gut physiology.
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Affiliation(s)
- Raquel Santos Souza
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Maiara do Valle Faria Gama
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Renata Schama
- Laboratory of Systems and Computational Biology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - José Bento Pereira Lima
- Laboratory of Physiology and Control of Arthropod Vectors, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | | | - Fernando Ariel Genta
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,National Institute of Science and Technology for Molecular Entomology, Rio de Janeiro, Brazil
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15
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Sackton TB. Comparative genomics and transcriptomics of host-pathogen interactions in insects: evolutionary insights and future directions. CURRENT OPINION IN INSECT SCIENCE 2019; 31:106-113. [PMID: 31109663 DOI: 10.1016/j.cois.2018.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 12/21/2018] [Accepted: 12/22/2018] [Indexed: 06/09/2023]
Abstract
Classical evolutionary studies of protein-coding genes have established that genes in the canonical immune system are often among the most rapidly evolving within and between species. As more genomes and transcriptomes across insects are sequenced, it is becoming clear that duplications and losses of immune genes are also a likely consequence of host-pathogen interactions. Furthermore, particular species respond to diverse pathogenic challenges with a wide range of challenge-specific responses that are still poorly understood. Transcriptional studies, using RNA-seq to characterize the infection-regulated transcriptome of diverse insects, are crucial for additional progress in understanding the ecology and evolution of the full complexity of the host response.
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Affiliation(s)
- Timothy B Sackton
- Informatics Group, Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, United States.
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16
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Kumar S, Chera JS, Vats A, De S. Nature of selection varies on different domains of IFI16-like PYHIN genes in ruminants. BMC Evol Biol 2019; 19:26. [PMID: 30654734 PMCID: PMC6335826 DOI: 10.1186/s12862-018-1334-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 12/17/2018] [Indexed: 12/11/2022] Open
Abstract
Background ALRs (AIM2-like Receptors) are germline encoded PRRs that belong to PYHIN gene family of cytokines, which are having signature N-terminal PYD (Pyrin, PAAD or DAPIN) domain and C-terminal HIN-200 (hematopoietic, interferon-inducible nuclear protein with 200 amino acid repeat) domain joined by a linker region. The positively charged HIN-200 domain senses and binds with negatively charged phosphate groups of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) purely through electrostatic attractions. On the other hand, PYD domain interacts homotypically with a PYD domain of other mediators to pass the signals to effector molecules downwards the pathways for inflammatory responses. There is remarkable inter-specific diversity in the numbers of functional PYHIN genes e.g. one in cow, five in human, thirteen in mice etc., while there is a unique loss of PYHIN genes in the bat genomes which was revealed by Ahn et al. (2016) by studying genomes of ten different bat species belonging to sub-orders yinpterochiroptera and yangochiroptera. The conflicts between host and pathogen interfaces are compared with “Red queen’s arms race” which is also described as binding seeking dynamics and binding avoidance dynamics. As a result of this never-ending rivalry, eukaryotes developed PRRs as antiviral mechanism while viruses developed counter mechanisms to evade host immune defense. The PYHIN receptors are directly engaged with pathogenic molecules, so these should have evolved under the influence of selection pressures. In the current study, we investigated the nature of selection pressure on different domain types of IFI16-like (IFI16-L) PYHIN genes in ruminants. Results Three transcript variants of the IFI16-like gene were found in PBMCs of ruminant animals-water buffalo, zebu cattle, goat, and sheep. The IFI16-like gene has one N-terminal PYD domain and one C-terminal HIN-200 domain, separated by an inter-domain linker region. HIN domain and inter-domain region are positively selected while the PYD domain is under the influence of purifying selection. Conclusion Herein, we conclude that the nature of selection pressure varies on different parts (PYD domain, HIN domain, and inter-domain linker region) of IFI16-like PYHIN genes in the ruminants. This data can be useful to predict the molecular determinants of pathogen interactions. Electronic supplementary material The online version of this article (10.1186/s12862-018-1334-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sushil Kumar
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, Haryana, 132001, India
| | - Jatinder Singh Chera
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, Haryana, 132001, India
| | - Ashutosh Vats
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, Haryana, 132001, India
| | - Sachinandan De
- Animal Genomics Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal, Haryana, 132001, India.
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17
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Policarpo IS, Vasconcellos A, Chaves TP, Raimundo JP, Medeiros ACD, Coutinho HDM, Alves RRN. Transference of bioactive compounds from support plants to the termites Constrictotermes cyphergaster (Isoptera). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 639:921-928. [PMID: 29929330 DOI: 10.1016/j.scitotenv.2018.05.173] [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: 02/03/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
This study aims to investigate the microbiological potential of the termite species Constrictotermes cyphergaster (Silvestri, 1901) and its support plants. We collected five C. cyphergaster nests from three different support plant species. Microbiological assays were performed on these extracts using the serial microdilution method in triplicate to measure the minimum inhibitory concentration (MIC) of each microorganism for the analysed extract. The ethanol extracts of the termite C. cyphergaster showed no significant activity against strains of Staphylococcus aureus and Escherichia coli, with an MIC >1000 μg mL-1. Only the extracts of the nests and termites with the nest had the same MICs. These results were in contrast to the extracts of Spondias tuberosa (Umbuzeiro), Poincianella pyramidalis (Catingueira), and Amburana cearensis (Cumaru), which demonstrated significant activity against S. aureus with MICs <1000 μg mL-1. The modulating activity of the extracts tested in the present study demonstrated potentiation of most antibiotics across the bacterial strains tested when combined with the extracts for both S. aureus and E. coli. These results indicate that the extracts tested in the present study may be composed of animal and vegetable origins with the potential to modify the activity of antibiotics and thus may aid in antimicrobial therapy.
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Affiliation(s)
- Iamara Silva Policarpo
- Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, Laboratório de Termitologia, 58051-900 João Pessoa, PB, Brazil
| | - Alexandre Vasconcellos
- Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, Laboratório de Termitologia, 58051-900 João Pessoa, PB, Brazil
| | - Thiago Pereira Chaves
- Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Bom Jesus, PI 64900-000, Brazil
| | - Joanda Paolla Raimundo
- Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Ana Cláudia D Medeiros
- Laboratório de Desenvolvimento e Ensaios de Medicamentos, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Henrique D M Coutinho
- Laboratório de Microbiologia e Biologia Molecular, Universidade Regional do Cariri, Crato, CE 63105-000, Brazil.
| | - Rômulo Romeu Nóbrega Alves
- Departamento de Biologia, Universidade Estadual da Paraíba, Laboratório de Termitologia, 58051-900 João Pessoa, PB, Brazil
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18
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Rolff J, Schmid-Hempel P. Perspectives on the evolutionary ecology of arthropod antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0297. [PMID: 27160599 DOI: 10.1098/rstb.2015.0297] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2016] [Indexed: 12/27/2022] Open
Abstract
Antimicrobial peptides (AMPs) are important elements of the innate immune defence in multicellular organisms that target and kill microbes. Here, we reflect on the various points that are raised by the authors of the 11 contributions to a special issue of Philosophical Transactions on the 'evolutionary ecology of arthropod antimicrobial peptides'. We see five interesting topics emerging. (i) AMP genes in insects, and perhaps in arthropods more generally, evolve much slower than most other immune genes. One explanation refers to the constraints set by AMPs being part of a finely tuned defence system. A new view argues that AMPs are under strong stabilizing selection. Regardless, this striking observation still invites many more questions than have been answered so far. (ii) AMPs almost always are expressed in combinations and sometimes show expression patterns that are dependent on the infectious agent. While it is often assumed that this can be explained by synergistic interactions, such interactions have rarely been demonstrated and need to be studied further. Moreover, how to define synergy in the first place remains difficult and needs to be addressed. (iii) AMPs play a very important role in mediating the interaction between a host and its mutualistic or commensal microbes. This has only been studied in a very small number of (insect) species. It has become clear that the very same AMPs play different roles in different situations and hence are under concurrent selection. (iv) Different environments shape the physiology of organisms; especially the host-associated microbial communities should impact on the evolution host AMPs. Studies in social insects and some organisms from extreme environments seem to support this notion, but, overall, the evidence for adaptation of AMPs to a given environment is scant. (v) AMPs are considered or already developed as new drugs in medicine. However, bacteria can evolve resistance to AMPs. Therefore, in the light of our limited understanding of AMP evolution in the natural context, and also the very limited understanding of the evolution of resistance against AMPs in bacteria in particular, caution is recommended. What is clear though is that study of the ecology and evolution of AMPs in natural systems could inform many of these outstanding questions, including those related to medical applications and pathogen control.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Jens Rolff
- Evolutionary Biology, Institute of Biology, Freie Universität Berlin, Königin-Luise-Strasse 1-3, 14195 Berlin, Germany Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany
| | - Paul Schmid-Hempel
- ETH Zürich, Institute of Integrative Biology (IBZ), ETH-Zentrum CHN, Universitätsstrasse 16, 8092 Zürich, Switzerland
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19
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Mitaka Y, Kobayashi K, Matsuura K. Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus. PLoS One 2017; 12:e0175417. [PMID: 28410430 PMCID: PMC5391962 DOI: 10.1371/journal.pone.0175417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/24/2017] [Indexed: 12/02/2022] Open
Abstract
Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole.
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Affiliation(s)
- Yuki Mitaka
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kazuya Kobayashi
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kenji Matsuura
- Laboratory of Insect Ecology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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20
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Velenovsky JF, Kalisch J, Bulmer MS. Selective sweeps in Cryptocercus woodroach antifungal proteins. Genetica 2016; 144:547-552. [DOI: 10.1007/s10709-016-9923-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/08/2016] [Indexed: 10/21/2022]
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21
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Zeng Y, Hu XP, Suh SJ. Characterization of Antibacterial Activities of Eastern Subterranean Termite, Reticulitermes flavipes, against Human Pathogens. PLoS One 2016; 11:e0162249. [PMID: 27611223 PMCID: PMC5017719 DOI: 10.1371/journal.pone.0162249] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/21/2016] [Indexed: 11/18/2022] Open
Abstract
The emergence and dissemination of multidrug resistant bacterial pathogens necessitate research to find new antimicrobials against these organisms. We investigated antimicrobial production by eastern subterranean termites, Reticulitermes flavipes, against a panel of bacteria including three multidrug resistant (MDR) and four non-MDR human pathogens. We determined that the crude extract of naïve termites had a broad-spectrum activity against the non-MDR bacteria but it was ineffective against the three MDR pathogens Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Acinetobacter baumannii. Heat or trypsin treatment resulted in a complete loss of activity suggesting that antibacterial activity was proteinaceous in nature. The antimicrobial activity changed dramatically when the termites were fed with either heat-killed P. aeruginosa or MRSA. Heat-killed P. aeruginosa induced activity against P. aeruginosa and MRSA while maintaining or slightly increasing activity against non-MDR bacteria. Heat-killed MRSA induced activity specifically against MRSA, altered the activity against two other Gram-positive bacteria, and inhibited activity against three Gram-negative bacteria. Neither the naïve termites nor the termites challenged with heat-killed pathogens produced antibacterial activity against A. baumannii. Further investigation demonstrated that hemolymph, not the hindgut, was the primary source of antibiotic activity. This suggests that the termite produces these antibacterial activities and not the hindgut microbiota. Two-dimensional gel electrophoretic analyses of 493 hemolymph protein spots indicated that a total of 38 and 65 proteins were differentially expressed at least 2.5-fold upon being fed with P. aeruginosa and MRSA, respectively. Our results provide the first evidence of constitutive and inducible activities produced by R. flavipes against human bacterial pathogens.
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Affiliation(s)
- Yuan Zeng
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States of America
| | - Xing Ping Hu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States of America
- * E-mail: (SS); (XPH)
| | - Sang-Jin Suh
- Department of Biological Sciences, Auburn University, Auburn University, Auburn, AL, United States of America
- * E-mail: (SS); (XPH)
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22
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Marxer M, Vollenweider V, Schmid-Hempel P. Insect antimicrobial peptides act synergistically to inhibit a trypanosome parasite. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150302. [PMID: 27160603 PMCID: PMC4874398 DOI: 10.1098/rstb.2015.0302] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2016] [Indexed: 11/12/2022] Open
Abstract
The innate immune system provides protection from infection by producing essential effector molecules, such as antimicrobial peptides (AMPs) that possess broad-spectrum activity. This is also the case for bumblebees, Bombus terrestris, when infected by the trypanosome, Crithidia bombi Furthermore, the expressed mixture of AMPs varies with host genetic background and infecting parasite strain (genotype). Here, we used the fact that clones of C. bombi can be cultivated and kept as strains in medium to test the effect of various combinations of AMPs on the growth rate of the parasite. In particular, we used pairwise combinations and a range of physiological concentrations of three AMPs, namely Abaecin, Defensin and Hymenoptaecin, synthetized from the respective genomic sequences. We found that these AMPs indeed suppress the growth of eight different strains of C. bombi, and that combinations of AMPs were typically more effective than the use of a single AMP alone. Furthermore, the most effective combinations were rarely those consisting of maximum concentrations. In addition, the AMP combination treatments revealed parasite strain specificity, such that strains varied in their sensitivity towards the same mixtures. Hence, variable expression of AMPs could be an alternative strategy to combat highly variable infections.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Monika Marxer
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Vera Vollenweider
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Paul Schmid-Hempel
- ETH Zurich, Institute of Integrative Biology (IBZ), Universitätsstrasse 16, 8092 Zürich, Switzerland
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23
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Patterns of molecular evolution of RNAi genes in social and socially parasitic bumblebees. INFECTION GENETICS AND EVOLUTION 2016; 42:53-9. [PMID: 27117935 DOI: 10.1016/j.meegid.2016.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/19/2016] [Accepted: 04/22/2016] [Indexed: 01/16/2023]
Abstract
The high frequency of interactions amongst closely related individuals in social insect colonies enhances pathogen transmission. Group-mediated behavior supporting immune defenses tends to decrease selection acting on immune genes. Along with low effective population sizes this might result in relaxed constraint and rapid evolution of immune system genes. Here, we show that antiviral siRNA genes show high rates of molecular evolution with argonaute 2, armitage and maelstrom evolving faster in social bumblebees compared to their socially parasitic cuckoo bumblebees that lack a worker caste. RNAi genes show frequent positive selection at the codon level additionally supported by the occurrence of parallel evolution. Their evolutionary rate is linked to their pathway specific position with genes directly interacting with viruses showing the highest rates of molecular evolution. We suggest that higher pathogen load in social insects indeed drives the molecular evolution of immune genes including antiviral siRNA, if not compensated by behavior.
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24
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Rosengaus RB, Reichheld JL. Phenoloxidase activity in the infraorder Isoptera: unraveling life-history correlates of immune investment. Naturwissenschaften 2016; 103:14. [PMID: 26838762 DOI: 10.1007/s00114-016-1338-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 01/19/2016] [Accepted: 01/21/2016] [Indexed: 11/25/2022]
Abstract
Within the area of ecological immunology, the quantification of phenoloxidase (PO) activity has been used as a proxy for estimating immune investment. Because termites have unique life-history traits and significant inter-specific differences exist regarding their nesting and foraging habits, comparative studies on PO activity can shed light on the general principles influencing immune investment against the backdrop of sociality, reproductive potential, and gender. We quantified PO activity across four termite species ranging from the phylogenetically basal to the most derived, each with their particular nesting/foraging strategies. Our data indicate that PO activity varies across species, with soil-dwelling termites exhibiting significantly higher PO levels than the above-ground wood nester species which in turn have higher PO levels than arboreal species. Moreover, our comparative approach suggests that pathogenic risks can override reproductive potential as a more important driver of immune investment. No gender-based differences in PO activities were recorded. Although termite PO activity levels vary in accordance with a priori predictions made from life-history theory, our data indicate that nesting and foraging strategies (and their resulting pathogenic pressures) can supersede reproductive potential and other life-history traits in influencing investment in PO. Termites, within the eusocial insects, provide a unique perspective for inferring how different ecological pressures may have influenced immune function in general and their levels of PO activity, in particular.
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Affiliation(s)
- Rebeca B Rosengaus
- Department of Marine and Environmental Sciences, Northeastern University, 134 Mugar Life Sciences Building, 360 Huntington Avenue, Boston, MA, 02115-5000, USA.
| | - Jennifer L Reichheld
- Department of Marine and Environmental Sciences, Northeastern University, 134 Mugar Life Sciences Building, 360 Huntington Avenue, Boston, MA, 02115-5000, USA
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25
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Chaves TP, Clementino EL, Felismino DC, Alves RR, Vasconcellos A, Coutinho HD, Medeiros ACD. Antibiotic resistance modulation by natural products obtained from Nasutitermes corniger (Motschulsky, 1855) and its nest. Saudi J Biol Sci 2015; 22:404-8. [PMID: 26150745 PMCID: PMC4486467 DOI: 10.1016/j.sjbs.2014.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/05/2014] [Accepted: 12/08/2014] [Indexed: 11/03/2022] Open
Abstract
Insects and their products are included in the traditional pharmacopoeia of various ethnic groups worldwide. In the Brazilian semiarid region can be highlighted the use of the termite Nasutitermes corniger for the treatment of various diseases. This study evaluated the ethanol extract of N. corniger and its nest as an antimicrobial agent and as a modulator of bacterial resistance against multidrug strains. The Minimum Inhibitory Concentration (MIC) of the extract on Staphylococcus aureus and Escherichia coli by microdilution was determined, as well as MIC of antibiotics in the presence and absence of extract. Despite having no significant antimicrobial activity (MIC ⩾ 1000 μg mL(-1)), the extract showed additive activity to the antibiotic efficacy, significantly reducing its MIC. These results suggest that N. corniger and its nest are promising natural products for use in antimicrobial therapy.
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Affiliation(s)
- Thiago P. Chaves
- Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Bom Jesus, PI 64900-000, Brazil
- Laboratório de Desenvolvimento e Ensaios de Medicamentos, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Elaine L.C. Clementino
- Laboratório de Desenvolvimento e Ensaios de Medicamentos, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Delcio C. Felismino
- Departamento de Biologia, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Rômulo R.N. Alves
- Departamento de Biologia, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
| | - Alexandre Vasconcellos
- Universidade Federal do Rio Grande do Norte, Departamento de Botânica, Ecologia e Zoologia, Natal, RN 59072-900, Brazil
| | - Henrique D.M. Coutinho
- Laboratório de Microbiologia e Biologia Molecular, Universidade Regional do Cariri, Crato, CE 63105-000, Brazil
| | - Ana Cláudia D. Medeiros
- Laboratório de Desenvolvimento e Ensaios de Medicamentos, Centro de Ciências Biológicas e da Saúde, Universidade Estadual da Paraíba, Campina Grande, Paraíba 58.429-500, Brazil
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de Figueirêdo RECR, Vasconcellos A, Policarpo IS, Alves RRN. Edible and medicinal termites: a global overview. JOURNAL OF ETHNOBIOLOGY AND ETHNOMEDICINE 2015; 11:29. [PMID: 25925503 PMCID: PMC4427943 DOI: 10.1186/s13002-015-0016-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/14/2015] [Indexed: 05/16/2023]
Abstract
Termites are mainly known for damage caused to human beings, both in urban and rural areas. However, these insects play an important role in the decomposition of organic matter in tropical regions and are important natural resources, which are widely used in traditional medicine and are also consumed by human populations in several parts of the world. This study aimed to catalogue termite species used worldwide through a literature review, characterizing them by its human populations' use. The results showed that at least 45 species of termites, belonging to four families, are used in the world, with 43 species used in human diet and/or in livestock feeding. Nine termite species are used as a therapeutic resource. There is an overlapping use of seven species. The use of termites was registered in 29 countries over three continents. Africa is the continent with the highest number of records, followed by America and Asia. The results suggest that, in addition to their ecological importance, termites are a source of medicinal and food resources to various human populations in various locations of the world, showing their potential for being used as an alternative protein source in human or livestock diets, as well as a source for new medicines.
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Affiliation(s)
| | - Alexandre Vasconcellos
- Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, Laboratório de Termitologia, 58051-900, João Pessoa, PB, Brazil.
| | - Iamara Silva Policarpo
- Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, Laboratório de Termitologia, 58051-900, João Pessoa, PB, Brazil.
| | - Rômulo Romeu Nóbrega Alves
- Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, Laboratório de Termitologia, 58051-900, João Pessoa, PB, Brazil.
- Departamento de Biologia, Universidade Estadual da Paraíba, Laboratório de Termitologia, 58051-900, João Pessoa, PB, Brazil.
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Sen R, Raychoudhury R, Cai Y, Sun Y, Lietze VU, Peterson BF, Scharf ME, Boucias DG. Molecular signatures of nicotinoid-pathogen synergy in the termite gut. PLoS One 2015; 10:e0123391. [PMID: 25837376 PMCID: PMC4383478 DOI: 10.1371/journal.pone.0123391] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/18/2015] [Indexed: 11/19/2022] Open
Abstract
Previous studies in lower termites revealed unexpected synergies between nicotinoid insecticides and fungal entomopathogens. The present study investigated molecular mechanisms of nicotinoid-pathogen synergy in the lower termite Reticulitermes flavipes, using the nicotinoid, imidacloprid, in combination with fungal and bacterial entomopathogens. Particular focus was placed on metatranscriptome composition and microbial dynamics in the symbiont-rich termite gut, which houses diverse mixes of protists and bacteria. cDNA microarrays containing a mix of host and protist symbiont oligonucleotides were used to simultaneously assess termite and protist gene expression. Five treatments were compared that included single challenges with sublethal doses of fungi (Metharizium anisopliae), bacteria (Serratia marcescens) or imidacloprid, and dual challenges with fungi + imidacloprid or bacteria + imidacloprid. Our findings point towards protist dysbiosis and compromised social behavior, rather than suppression of stereotypical immune defense mechanisms, as the dominant factors underlying nicotinoid-pathogen synergy in termites. Also, greater impacts observed for the fungal pathogen than for the bacterial pathogen suggest that the rich bacterial symbiont community in the R. flavipes gut (>5000 species-level phylotypes) exists in an ecological balance that effectively excludes exogenous bacterial pathogens. These findings significantly advance our understanding of antimicrobial defenses in this important eusocial insect group, as well as provide novel insights into how nicotinoids can exert deleterious effects on social insect colonies.
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Affiliation(s)
- Ruchira Sen
- Dept. of Entomology, Purdue University, West Lafayette, IN, United States of America
| | - Rhitoban Raychoudhury
- Dept. of Entomology, Purdue University, West Lafayette, IN, United States of America
| | - Yunpeng Cai
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States of America
| | - Yijun Sun
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, United States of America
| | - Verena-Ulrike Lietze
- Entomology and Nematology Department, University of Florida, Gainesville, FL, United States of America
| | - Brittany F. Peterson
- Dept. of Entomology, Purdue University, West Lafayette, IN, United States of America
| | - Michael E. Scharf
- Dept. of Entomology, Purdue University, West Lafayette, IN, United States of America
| | - Drion G. Boucias
- Entomology and Nematology Department, University of Florida, Gainesville, FL, United States of America
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Abstract
Patterns of evolution in immune defense genes help to understand the evolutionary dynamics between hosts and pathogens. Multiple insect genomes have been sequenced, with many of them having annotated immune genes, which paves the way for a comparative genomic analysis of insect immunity. In this review, I summarize the current state of comparative and evolutionary genomics of insect innate immune defense. The focus is on the conserved and divergent components of immunity with an emphasis on gene family evolution and evolution at the sequence level; both population genetics and molecular evolution frameworks are considered.
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Korb J, Poulsen M, Hu H, Li C, Boomsma JJ, Zhang G, Liebig J. A genomic comparison of two termites with different social complexity. Front Genet 2015; 6:9. [PMID: 25788900 PMCID: PMC4348803 DOI: 10.3389/fgene.2015.00009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/09/2015] [Indexed: 11/15/2022] Open
Abstract
The termites evolved eusociality and complex societies before the ants, but have been studied much less. The recent publication of the first two termite genomes provides a unique comparative opportunity, particularly because the sequenced termites represent opposite ends of the social complexity spectrum. Zootermopsis nevadensis has simple colonies with totipotent workers that can develop into all castes (dispersing reproductives, nest-inheriting replacement reproductives, and soldiers). In contrast, the fungus-growing termite Macrotermes natalensis belongs to the higher termites and has very large and complex societies with morphologically distinct castes that are life-time sterile. Here we compare key characteristics of genomic architecture, focusing on genes involved in communication, immune defenses, mating biology and symbiosis that were likely important in termite social evolution. We discuss these in relation to what is known about these genes in the ants and outline hypothesis for further testing.
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Affiliation(s)
- Judith Korb
- Department of Evolutionary Biology and Ecology, Institute of Biology I, University of FreiburgFreiburg, Germany
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, Centre for Social Evolution, University of CopenhagenCopenhagen, Denmark
| | - Haofu Hu
- China National Genebank, BGI-ShenzhenShenzhen, China
| | - Cai Li
- China National Genebank, BGI-ShenzhenShenzhen, China
- Centre for GeoGenetics, Natural History Museum of Denmark, University of CopenhagenCopenhagen, Denmark
| | - Jacobus J. Boomsma
- Section for Ecology and Evolution, Department of Biology, Centre for Social Evolution, University of CopenhagenCopenhagen, Denmark
| | - Guojie Zhang
- Section for Ecology and Evolution, Department of Biology, Centre for Social Evolution, University of CopenhagenCopenhagen, Denmark
- China National Genebank, BGI-ShenzhenShenzhen, China
| | - Jürgen Liebig
- School of Life Sciences, Arizona State UniversityTempe, AZ, USA
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Abstract
Termites have many unique evolutionary adaptations associated with their eusocial lifestyles. Recent omics research has created a wealth of new information in numerous areas of termite biology (e.g., caste polyphenism, lignocellulose digestion, and microbial symbiosis) with wide-ranging applications in diverse biotechnological niches. Termite biotechnology falls into two categories: (a) termite-targeted biotechnology for pest management purposes, and (b) termite-modeled biotechnology for use in various industrial applications. The first category includes several candidate termiticidal modes of action such as RNA interference, digestive inhibition, pathogen enhancement, antimicrobials, endocrine disruption, and primer pheromone mimicry. In the second category, termite digestomes are deep resources for host and symbiont lignocellulases and other enzymes with applications in a variety of biomass, industrial, and processing applications. Moving forward, one of the most important approaches for accelerating advances in both termite-targeted and termite-modeled biotechnology will be to consider host and symbiont together as a single functional unit.
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Affiliation(s)
- Michael E Scharf
- Department of Entomology, Purdue University, West Lafayette, Indiana 47907;
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Abstract
Natural selection is expected to drive adaptive evolution in genes involved in host–pathogen interactions. In this study, we use molecular population genetic analyses to understand how natural selection operates on the immune system of Anopheles coluzzii (formerly A. gambiae “M form”). We analyzed patterns of intraspecific and interspecific genetic variation in 20 immune-related genes and 17 nonimmune genes from a wild population of A. coluzzii and asked if patterns of genetic variation in the immune genes are consistent with pathogen-driven selection shaping the evolution of defense. We found evidence of a balanced polymorphism in CTLMA2, which encodes a C-type lectin involved in regulation of the melanization response. The two CTLMA2 haplotypes, which are distinguished by fixed amino acid differences near the predicted peptide cleavage site, are also segregating in the sister species A. gambiae (“S form”) and A. arabiensis. Comparison of the two haplotypes between species indicates that they were not shared among the species through introgression, but rather that they arose before the species divergence and have been adaptively maintained as a balanced polymorphism in all three species. We additionally found that STAT-B, a retroduplicate of STAT-A, shows strong evidence of adaptive evolution that is consistent with neofunctionalization after duplication. In contrast to the striking patterns of adaptive evolution observed in these Anopheles-specific immune genes, we found no evidence of adaptive evolution in the Toll and Imd innate immune pathways that are orthologously conserved throughout insects. Genes encoding the Imd pathway exhibit high rates of amino acid divergence between Anopheles species but also display elevated amino acid diversity that is consistent with relaxed purifying selection. These results indicate that adaptive coevolution between A. coluzzii and its pathogens is more likely to involve novel or lineage-specific molecular mechanisms than the canonical humoral immune pathways.
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Otti O, Tragust S, Feldhaar H. Unifying external and internal immune defences. Trends Ecol Evol 2014; 29:625-34. [DOI: 10.1016/j.tree.2014.09.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 08/28/2014] [Accepted: 09/09/2014] [Indexed: 10/24/2022]
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van Mierlo JT, Overheul GJ, Obadia B, van Cleef KWR, Webster CL, Saleh MC, Obbard DJ, van Rij RP. Novel Drosophila viruses encode host-specific suppressors of RNAi. PLoS Pathog 2014; 10:e1004256. [PMID: 25032815 PMCID: PMC4102588 DOI: 10.1371/journal.ppat.1004256] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 06/03/2014] [Indexed: 12/24/2022] Open
Abstract
The ongoing conflict between viruses and their hosts can drive the co-evolution between host immune genes and viral suppressors of immunity. It has been suggested that an evolutionary ‘arms race’ may occur between rapidly evolving components of the antiviral RNAi pathway of Drosophila and viral genes that antagonize it. We have recently shown that viral protein 1 (VP1) of Drosophila melanogaster Nora virus (DmelNV) suppresses Argonaute-2 (AGO2)-mediated target RNA cleavage (slicer activity) to antagonize antiviral RNAi. Here we show that viral AGO2 antagonists of divergent Nora-like viruses can have host specific activities. We have identified novel Nora-like viruses in wild-caught populations of D. immigrans (DimmNV) and D. subobscura (DsubNV) that are 36% and 26% divergent from DmelNV at the amino acid level. We show that DimmNV and DsubNV VP1 are unable to suppress RNAi in D. melanogaster S2 cells, whereas DmelNV VP1 potently suppresses RNAi in this host species. Moreover, we show that the RNAi suppressor activity of DimmNV VP1 is restricted to its natural host species, D. immigrans. Specifically, we find that DimmNV VP1 interacts with D. immigrans AGO2, but not with D. melanogaster AGO2, and that it suppresses slicer activity in embryo lysates from D. immigrans, but not in lysates from D. melanogaster. This species-specific interaction is reflected in the ability of DimmNV VP1 to enhance RNA production by a recombinant Sindbis virus in a host-specific manner. Our results emphasize the importance of analyzing viral RNAi suppressor activity in the relevant host species. We suggest that rapid co-evolution between RNA viruses and their hosts may result in host species-specific activities of RNAi suppressor proteins, and therefore that viral RNAi suppressors could be host-specificity factors. Viruses and their hosts can engage in an evolutionary arms race. Viruses may select for hosts with more effective immune responses, whereas the immune response of the host may select for viruses that evade the immune system. These viral counter-defenses may in turn drive adaptations in host immune genes. A potential outcome of this perpetual cycle is that the interaction between virus and host becomes more specific. In insects, the host antiviral RNAi machinery exerts strong evolutionary pressure that has led to the evolution of viral proteins that can antagonize the RNAi response. We have identified novel viruses that infect different fruit fly species and we show that the RNAi suppressor proteins of these viruses can be specific to their host. Furthermore, we show that these proteins can enhance virus replication in a host-specific manner. These results are in line with the hypothesis that virus-host co-evolution shapes the genomes of both virus and host. Moreover, our results suggest that RNAi suppressor proteins have the potential to determine host specificity of viruses.
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Affiliation(s)
- Joël T. van Mierlo
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Gijs J. Overheul
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Benjamin Obadia
- Institut Pasteur, Viruses and RNA interference Unit and Centre National de la Recherche Scientifique, UMR 3569, Paris, France
| | - Koen W. R. van Cleef
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Claire L. Webster
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Maria-Carla Saleh
- Institut Pasteur, Viruses and RNA interference Unit and Centre National de la Recherche Scientifique, UMR 3569, Paris, France
| | - Darren J. Obbard
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (DJO); (RPvR)
| | - Ronald P. van Rij
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
- * E-mail: (DJO); (RPvR)
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Erler S, Lhomme P, Rasmont P, Lattorff HMG. Rapid evolution of antimicrobial peptide genes in an insect host–social parasite system. INFECTION GENETICS AND EVOLUTION 2014; 23:129-37. [DOI: 10.1016/j.meegid.2014.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 01/08/2014] [Accepted: 02/07/2014] [Indexed: 10/25/2022]
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Sackton TB, Werren JH, Clark AG. Characterizing the infection-induced transcriptome of Nasonia vitripennis reveals a preponderance of taxonomically-restricted immune genes. PLoS One 2013; 8:e83984. [PMID: 24386321 PMCID: PMC3873987 DOI: 10.1371/journal.pone.0083984] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/10/2013] [Indexed: 12/19/2022] Open
Abstract
The innate immune system in insects consists of a conserved core signaling network and rapidly diversifying effector and recognition components, often containing a high proportion of taxonomically-restricted genes. In the absence of functional annotation, genes encoding immune system proteins can thus be difficult to identify, as homology-based approaches generally cannot detect lineage-specific genes. Here, we use RNA-seq to compare the uninfected and infection-induced transcriptome in the parasitoid wasp Nasonia vitripennis to identify genes regulated by infection. We identify 183 genes significantly up-regulated by infection and 61 genes significantly down-regulated by infection. We also produce a new homology-based immune catalog in N. vitripennis, and show that most infection-induced genes cannot be assigned an immune function from homology alone, suggesting the potential for substantial novel immune components in less well-studied systems. Finally, we show that a high proportion of these novel induced genes are taxonomically restricted, highlighting the rapid evolution of immune gene content. The combination of functional annotation using RNA-seq and homology-based annotation provides a robust method to characterize the innate immune response across a wide variety of insects, and reveals significant novel features of the Nasonia immune response.
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Affiliation(s)
- Timothy B. Sackton
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - John H. Werren
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Andrew G. Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
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Hussain A, Li YF, Cheng Y, Liu Y, Chen CC, Wen SY. Immune-related transcriptome of Coptotermes formosanus Shiraki workers: the defense mechanism. PLoS One 2013; 8:e69543. [PMID: 23874972 PMCID: PMC3712931 DOI: 10.1371/journal.pone.0069543] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 06/14/2013] [Indexed: 12/26/2022] Open
Abstract
Formosan subterranean termites, Coptotermes formosanus Shiraki, live socially in microbial-rich habitats. To understand the molecular mechanism by which termites combat pathogenic microbes, a full-length normalized cDNA library and four Suppression Subtractive Hybridization (SSH) libraries were constructed from termite workers infected with entomopathogenic fungi (Metarhizium anisopliae and Beauveria bassiana), Gram-positive Bacillus thuringiensis and Gram-negative Escherichia coli, and the libraries were analyzed. From the high quality normalized cDNA library, 439 immune-related sequences were identified. These sequences were categorized as pattern recognition receptors (47 sequences), signal modulators (52 sequences), signal transducers (137 sequences), effectors (39 sequences) and others (164 sequences). From the SSH libraries, 27, 17, 22 and 15 immune-related genes were identified from each SSH library treated with M. anisopliae, B. bassiana, B. thuringiensis and E. coli, respectively. When the normalized cDNA library was compared with the SSH libraries, 37 immune-related clusters were found in common; 56 clusters were identified in the SSH libraries, and 259 were identified in the normalized cDNA library. The immune-related gene expression pattern was further investigated using quantitative real time PCR (qPCR). Important immune-related genes were characterized, and their potential functions were discussed based on the integrated analysis of the results. We suggest that normalized cDNA and SSH libraries enable us to discover functional genes transcriptome. The results remarkably expand our knowledge about immune-inducible genes in C. formosanus Shiraki and enable the future development of novel control strategies for the management of Formosan subterranean termites.
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Affiliation(s)
- Abid Hussain
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
| | - Yi-Feng Li
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
| | - Yu Cheng
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
| | - Yang Liu
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
| | - Chuan-Cheng Chen
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
| | - Shuo-Yang Wen
- Department of Entomology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, P. R. China
- * E-mail:
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Kirsch R, Wielsch N, Vogel H, Svatoš A, Heckel DG, Pauchet Y. Combining proteomics and transcriptome sequencing to identify active plant-cell-wall-degrading enzymes in a leaf beetle. BMC Genomics 2012; 13:587. [PMID: 23116131 PMCID: PMC3505185 DOI: 10.1186/1471-2164-13-587] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 10/29/2012] [Indexed: 11/24/2022] Open
Abstract
Background The primary plant cell wall is a complex mixture of polysaccharides and proteins encasing living plant cells. Among these polysaccharides, cellulose is the most abundant and useful biopolymer present on earth. These polysaccharides also represent a rich source of energy for organisms which have evolved the ability to degrade them. A growing body of evidence suggests that phytophagous beetles, mainly species from the superfamilies Chrysomeloidea and Curculionoidea, possess endogenous genes encoding complex and diverse families of so-called plant cell wall degrading enzymes (PCWDEs). The presence of these genes in phytophagous beetles may have been a key element in their success as herbivores. Here, we combined a proteomics approach and transcriptome sequencing to identify PCWDEs present in larval gut contents of the mustard leaf beetle, Phaedon cochleariae. Results Using a two-dimensional proteomics approach, we recovered 11 protein bands, isolated using activity assays targeting cellulose-, pectin- and xylan-degrading enzymes. After mass spectrometry analyses, a total of 13 proteins putatively responsible for degrading plant cell wall polysaccharides were identified; these proteins belong to three glycoside hydrolase (GH) families: GH11 (xylanases), GH28 (polygalacturonases or pectinases), and GH45 (β-1,4-glucanases or cellulases). Additionally, highly stable and proteolysis-resistant host plant-derived proteins from various pathogenesis-related protein (PRs) families as well as polygalacturonase-inhibiting proteins (PGIPs) were also identified from the gut contents proteome. In parallel, transcriptome sequencing revealed the presence of at least 19 putative PCWDE transcripts encoded by the P. cochleariae genome. All of these were specifically expressed in the insect gut rather than the rest of the body, and in adults as well as larvae. The discrepancy observed in the number of putative PCWDEs between transcriptome and proteome analyses could be partially explained by differences in transcriptional level. Conclusions Combining proteome and transcriptome sequencing analyses proved to be a powerful tool for the discovery of active PCWDEs in a non-model species. Our data represent the starting point of an in-depth functional and evolutionary characterization of PCWDE gene families in phytophagous beetles and their contribution to the adaptation of these highly successful herbivores to their host plants.
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Affiliation(s)
- Roy Kirsch
- Entomology Department, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany
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Jin P, Zhou L, Song X, Qian J, Chen L, Ma F. Particularity and universality of a putative Gram-negative bacteria-binding protein (GNBP) gene from amphioxus (Branchiostoma belcheri): insights into the function and evolution of GNBP. FISH & SHELLFISH IMMUNOLOGY 2012; 33:835-845. [PMID: 22986589 DOI: 10.1016/j.fsi.2012.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 07/05/2012] [Accepted: 07/26/2012] [Indexed: 06/01/2023]
Abstract
Gram-negative bacteria-binding proteins (GNBPs) are important pattern recognition proteins (PRPs), which can initiate host defense in response to pathogen surface molecules. The roles of GNBP in innate immunity of arthropods and molluscs have recently been reported. However, the GNBP gene has not been characterized in the species of higher evolutionary status yet. In this study, we identified and characterized an amphioxus GNBP gene (designated as AmphiGNBP). First, we identified and cloned the AmphiGNBP and found that the AmphiGNBP encodes a putative protein with 558 amino acids, which contains a conserved β-1, 3-glucan recognizing and binding domain. Second, we found that the AmphiGNBP encodes two extra WSC (cell Wall integrity and Stress response Component) domains, which are unique in AmphiGNBP protein. The two WSC domains of AmphiGNBP protein coupled with the expansion of amphioxus immunity repertoire might undergo intensive domain shuffling during the age of the Cambrian explosion. Finally, we found that the AmphiGNBP was mainly expressed in immune tissues, such as hepatic cecum and intestine, and the expression of AmphiGNBP was affected after LPS stimulation. In conclusion, our findings disclose the particularity and universality of AmphiGNBP and provide profound insights into the function and evolution of GNBP.
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Affiliation(s)
- Ping Jin
- Laboratory for Comparative Genomics and Bioinformatics & Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, China
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Gao Q, Tancredi SE, Thompson GJ. Identification of mycosis-related genes in the eastern subterranean termite by suppression subtractive hybridization. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2012; 80:63-76. [PMID: 22549993 DOI: 10.1002/arch.21026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Eastern subterranean termite Reticulitermes flavipes (Isoptera, Rhinotermitidae) is a cosmopolitan, structural pest that is the target of research into termite innate immunity. In this study, we use suppression subtractive hybridization to construct a normalized cDNA library of genes excessively expressed upon fungal infection. At 24 h postinfection with Metarhizium anisopliae, the library revealed 182 expressed sequence tag (EST) clones that potentially represent immune responsive genes. The nucleotide sequence from a majority (97%) of ESTs assembled into a small number (n = 13) of contiguous sequences, with the remainder (n = 6) representing singletons. Our screen therefore captured as many as 19 different mRNAs highly expressed in response to the fungal pathogen at this time. Primary sequencing of all loci revealed that approximately half (n = 10) contained open reading frames with significant similarity to known proteins. These clones represent nuclear and mitochondrial coding genes, as well as putative long noncoding RNA genes. Quantitative polymerase chain reaction analysis of coding genes on independently infected groups of worker termites confirms in each case that the transcripts identified from the library are up-regulated postfungal infection. The genes identified here are relevant to future studies on termite biocontrol and social insect immunity.
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Affiliation(s)
- Qi Gao
- Department of Biology, Western University, London, Canada
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Siva VS, Yang C, Yang J, Wang L, Wang L, Zhou Z, Qiu L, Song L. Association of CfLGBP gene polymorphism with disease susceptibility/resistance of Zhikong scallop (Chlamys farreri) to Listonella anguillarum. FISH & SHELLFISH IMMUNOLOGY 2012; 32:1117-1123. [PMID: 22465359 DOI: 10.1016/j.fsi.2012.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 03/15/2012] [Accepted: 03/15/2012] [Indexed: 05/31/2023]
Abstract
Lipopolysaccharide and β-1, 3-glucan binding protein (LGBP) is a pattern recognition receptor (PRR) recognizing and binding both LPS and β-1, 3-glucan, playing important roles in innate immunity. In the present study, the single nucleotide polymorphisms (SNPs) were assessed in LGBP gene from scallop Chlamys farreri (designated CfLGBP), and eight SNPs were found in its potential LPS and glucanase binding motif. The locus +7679 with the transition of G-A, which produced an amino acid substitution at codon 360 from a non polar Glycine to polar Serine, was selected to inspect their association with disease resistance/susceptibility to Listonella anguillarum. Three genotypes G/G, G/A and A/A, were revealed at locus +7679, and their frequencies were 89.7%, 7.7% and 2.6% in the resistant stock, while 63.2%, 34.2% and 2.6% in the susceptible stock, respectively. The frequency of genotypes G/G and G/A were significantly different (P < 0.05) between the two stocks. The pathogen-associated molecular patterns (PAMP) binding activity of two recombinant proteins, rCfLGBP (G) with G variant at locus +7679 and rCfLGBP (S) with A variant at locus +7679, were elucidated by ELISA assay. The binding affinities of both LPS and β-glucan binding affinity were varied in a dose-dependent manner, where the binding affinity of rCfLGBP (G) was significantly higher than that of rCfLGBP (S) (P < 0.05). The results collectively suggested that the polymorphism of +7679 G/G in CfLGBP possibly enhances the binding activity of LPS and β-glucan, and was associated to disease resistance of scallop against L. anguillarum, which could be a potential marker applied in future selection of scallop with enhanced resistance to L. anguillarum.
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Affiliation(s)
- Vinu S Siva
- Key laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
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41
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Evolution of the βGRP/GNBP/β-1,3-glucanase family of insects. Immunogenetics 2012; 64:549-58. [DOI: 10.1007/s00251-012-0610-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/29/2012] [Indexed: 11/28/2022]
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Hamilton C, Bulmer MS. Molecular antifungal defenses in subterranean termites: RNA interference reveals in vivo roles of termicins and GNBPs against a naturally encountered pathogen. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2012; 36:372-377. [PMID: 21824492 DOI: 10.1016/j.dci.2011.07.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/22/2011] [Accepted: 07/22/2011] [Indexed: 05/27/2023]
Abstract
Subterranean termites face strong pathogenic pressures from the ubiquitous soil fungus Metarhizium anisopliae, and rely on innate humoral and cellular, as well as behavioral immune defenses for protection. Reticulitermes termites secrete antifungal enzymes that exhibit strong β-1,3-glucanase activity associated with Gram-negative bacteria binding proteins (GNBPs), which prevent M. anisopliae from invading the hemocoel where it can evade immune responses. Molecular evolutionary studies of Reticulitermes termicin genes, which code for defensin-like antifungal peptides, suggest that these proteins may be important effector molecules in antifungal defenses. In this study we show that the RNAi knockdown of termicin and GNBP2 expression via the ingestion of dsRNA significantly increases mortality in termites exposed to a naturally encountered strain of M. anisopliae. Termicin and GNBP2 knockdown also decrease external cuticular antifungal activity, indicating a direct role for these proteins in an external antifungal defense strategy that depends on the active dissemination of antifungal secretions among nestmates.
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Affiliation(s)
- Casey Hamilton
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA.
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Hamilton C, Lay F, Bulmer MS. Subterranean termite prophylactic secretions and external antifungal defenses. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1259-1266. [PMID: 21708164 DOI: 10.1016/j.jinsphys.2011.05.016] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 05/25/2011] [Accepted: 05/27/2011] [Indexed: 05/27/2023]
Abstract
Termites exploit environments that make them susceptible to infection and rapid disease transmission. Gram-negative bacteria binding proteins (GNBPs) signal the presence of microbes and in some insects directly damage fungal pathogens with β-1,3-glucanase activity. The subterranean termites Reticulitermes flavipes and Reticulitermes virginicus encounter soil entomopathogenic fungi such as Metarhizium anisopliae, which can evade host immune responses after penetrating the cuticle. An external defense that prevents invasion of fungal pathogens could be crucial in termites, allowing them to thrive under high pathogenic pressures. We investigated the role of secreted β-1,3-glucanases in Reticulitermes defenses against M. anisopliae. Our results show that these termites secrete antifungal β-1,3-glucanases on the cuticle, and the specific inhibition of GNBP associated β-1,3-glucanase activity with d-δ-gluconolactone (GDL) reduces this activity and can cause significant increases in mortality after exposure to M. anisopliae. Secreted β-1,3-glucanases appear to be essential in preventing infection by breaking down fungi externally.
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Affiliation(s)
- Casey Hamilton
- Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252, USA.
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Hult EF, Tobe SS, Chang BSW. Molecular evolution of ultraspiracle protein (USP/RXR) in insects. PLoS One 2011; 6:e23416. [PMID: 21901121 PMCID: PMC3162005 DOI: 10.1371/journal.pone.0023416] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 07/16/2011] [Indexed: 12/20/2022] Open
Abstract
Ultraspiracle protein/retinoid X receptor (USP/RXR) is a nuclear receptor and transcription factor which is an essential component of a heterodimeric receptor complex with the ecdysone receptor (EcR). In insects this complex binds ecdysteroids and plays an important role in the regulation of growth, development, metamorphosis and reproduction. In some holometabolous insects, including Lepidoptera and Diptera, USP/RXR is thought to have experienced several important shifts in function. These include the acquisition of novel ligand-binding properties and an expanded dimerization interface with EcR. In light of these recent hypotheses, we implemented codon-based likelihood methods to investigate if the proposed shifts in function are reflected in changes in site-specific evolutionary rates across functional and structural motifs in insect USP/RXR sequences, and if there is any evidence for positive selection at functionally important sites. Our results reveal evidence of positive selection acting on sites within the loop connecting helices H1 and H3, the ligand-binding pocket, and the dimer interface in the holometabolous lineage leading to the Lepidoptera/Diptera/Trichoptera. Similar analyses conducted using EcR sequences did not indicate positive selection. However, analyses allowing for variation across sites demonstrated elevated non-synonymous/synonymous rate ratios (d(N)/d(S)), suggesting relaxed constraint, within the dimerization interface of both USP/RXR and EcR as well as within the coactivator binding groove and helix H12 of USP/RXR. Since the above methods are based on the assumption that d(S) is constant among sites, we also used more recent models which relax this assumption and obtained results consistent with traditional random-sites models. Overall our findings support the evolution of novel function in USP/RXR of more derived holometabolous insects, and are consistent with shifts in structure and function which may have increased USP/RXR reliance on EcR for cofactor recruitment. Moreover, these findings raise important questions regarding hypotheses which suggest the independent activation of USP/RXR by its own ligand.
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Affiliation(s)
- Ekaterina F. Hult
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Stephen S. Tobe
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Belinda S. W. Chang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
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Fischman BJ, Woodard SH, Robinson GE. Molecular evolutionary analyses of insect societies. Proc Natl Acad Sci U S A 2011; 108 Suppl 2:10847-54. [PMID: 21690385 PMCID: PMC3131825 DOI: 10.1073/pnas.1100301108] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The social insects live in extraordinarily complex and cohesive societies, where many individuals sacrifice their personal reproduction to become helpers in the colony. Identifying adaptive molecular changes involved in eusocial evolution in insects is important for understanding the mechanisms underlying transitions from solitary to social living, as well as the maintenance and elaboration of social life. Here, we review recent advances made in this area of research in several insect groups: the ants, bees, wasps, and termites. Drawing from whole-genome comparisons, candidate gene approaches, and a genome-scale comparative analysis of protein-coding sequence, we highlight novel insights gained for five major biological processes: chemical signaling, brain development and function, immunity, reproduction, and metabolism and nutrition. Lastly, we make comparisons across these diverse approaches and social insect lineages and discuss potential common themes of eusocial evolution, as well as challenges and prospects for future research in the field.
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Affiliation(s)
| | | | - Gene E. Robinson
- Program in Ecology, Evolution, and Conservation Biology
- Department of Entomology
- Institute for Genomic Biology, and
- Neuroscience Program, University of Illinois, Urbana, IL 61801
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Bragatto I, Genta FA, Ribeiro AF, Terra WR, Ferreira C. Characterization of a β-1,3-glucanase active in the alkaline midgut of Spodoptera frugiperda larvae and its relation to β-glucan-binding proteins. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2010; 40:861-872. [PMID: 20816775 DOI: 10.1016/j.ibmb.2010.08.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/23/2010] [Accepted: 08/25/2010] [Indexed: 05/29/2023]
Abstract
Spodoptera frugiperda β-1,3-glucanase (SLam) was purified from larval midgut. It has a molecular mass of 37.5 kDa, an alkaline optimum pH of 9.0, is active against β-1,3-glucan (laminarin), but cannot hydrolyze yeast β-1,3-1,6-glucan or other polysaccharides. The enzyme is an endoglucanase with low processivity (0.4), and is not inhibited by high concentrations of substrate. In contrast to other digestive β-1,3-glucanases from insects, SLam is unable to lyse Saccharomyces cerevisae cells. The cDNA encoding SLam was cloned and sequenced, showing that the protein belongs to glycosyl hydrolase family 16 as other insect glucanases and glucan-binding proteins. Multiple sequence alignment of β-1,3-glucanases and β-glucan-binding protein supports the assumption that the β-1,3-glucanase gene duplicated in the ancestor of mollusks and arthropods. One copy originated the derived β-1,3-glucanases by the loss of an extended N-terminal region and the β-glucan-binding proteins by the loss of the catalytic residues. SLam homology modeling suggests that E228 may affect the ionization of the catalytic residues, thus displacing the enzyme pH optimum. SLam antiserum reacts with a single protein in the insect midgut. Immunocytolocalization shows that the enzyme is present in secretory vesicles and glycocalyx from columnar cells.
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Affiliation(s)
- Ivan Bragatto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, CP 26077, 05513-970 São Paulo, Brazil
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47
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Bulmer MS, Lay F, Hamilton C. Adaptive evolution in subterranean termite antifungal peptides. INSECT MOLECULAR BIOLOGY 2010; 19:669-674. [PMID: 20561089 DOI: 10.1111/j.1365-2583.2010.01023.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We identified and analysed mRNA sequences of two immune proteins from the subterranean termites Reticulitermes flavipes and Reticulitermes virginicus. These proteins correspond to two immune proteins described in the distantly related termite genus Nasutitermes; termicin, which is a small antifungal peptide, and GNBP2, which functions both as a broad pattern recognition receptor and a direct antifungal effector. A population genetic analysis of nucleotide intraspecific polymorphism and interspecific divergence indicates that a selective sweep has reduced polymorphism in the termicins. Moreover, this selective sweep appears to have been driven by the positive selection of beneficial amino acid changes in the antifungal peptide. In contrast, the pattern of polymorphism and divergence in GNBP2 corresponds to the standard neutral model of evolution.
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Affiliation(s)
- M S Bulmer
- Department of Biological Sciences, Towson University, Towson, MD21252, USA.
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48
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Coutinho HDM, Vasconcellos A, Freire-Pessôa HL, Gadelha CA, Gadelha TS, Almeida-Filho GG. Natural products from the termite Nasutitermes corniger lowers aminoglycoside minimum inhibitory concentrations. Pharmacogn Mag 2010; 6:1-4. [PMID: 20548928 PMCID: PMC2881651 DOI: 10.4103/0973-1296.59958] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 12/02/2009] [Accepted: 02/13/2010] [Indexed: 11/18/2022] Open
Abstract
Bacterial infectious agents present a risk to populations, as they are responsible for high morbidity and mortality. For combating these pathogens, our main line of defense is the use of antibiotics. However, indiscriminate use of these drugs develops resistant strains to these same drugs. The present study has tested the antibacterial and modifying antibiotic activity of natural products from Nasutitermes corniger (Termitidae) (Motschulsky), a termite used in folk medicine in Northeast Brazil, by the microdilution and checkerboard methods, respectively. In this study, the aqueous extract from the nest of N. corniger (ANCE) was prepared and tested with chlorpromazine (CPZ) for its antimicrobial activity, using the microdilution method. CPZ and ANCE were used independently and also in combination with aminoglycosides, against a strain of Escherichia coli resistant to these antibiotics, to determine the participation of efflux systems in resistance mechanisms. The fractional inhibitory concentration (FIC) index was calculated and evaluated for the occurrence of synergism, using the checkerboard method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) values were ≥ 2048 μg/mL for both strains of E. coli assayed, indicating low antibacterial activity. However, synergism was observed with kanamycin when the decoction was used, but when chlorpromazine was used, synergism was observed with kanamycin, amikacin, and neomycin. This synergism with CPZ indicated the involvement of an efflux system in the resistance to these aminoglycosides. Therefore, it was suggested that the natural products from N. corniger could be used as a source of zoo-derived natural products with kanamycin-modifying activity, resulting in a new approach against bacterial resistance to antibiotics.
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Affiliation(s)
- Henrique D M Coutinho
- Laboratório de Pesquisa em Produtos Naturais, Departamento de Ciências Biológicas, Universidade Regional do Cariri, Crato (CE), 63105-000, Brazil
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Coutinho HDM, Vasconcellos A, Lima MA, Almeida-Filho GG, Alves RRN. Termite usage associated with antibiotic therapy: enhancement of aminoglycoside antibiotic activity by natural products of Nasutitermes corniger (Motschulsky 1855). BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2009; 9:35. [PMID: 19761599 PMCID: PMC2751743 DOI: 10.1186/1472-6882-9-35] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 09/17/2009] [Indexed: 11/10/2022]
Abstract
Background Several species from Insecta are used as remedies. Among these species, the termite Nasutitermes corniger is commonly used in traditional medicine in Northeast Brazil. The present work tests the modifying antibiotic activity of Nasutitermes corniger, a termite used in folk medicine in Northeastern region of Brazil. Methods Chlorpromazine and decocts of N. corniger were collected from two different plant species used in the traditional medicine were tested for their antimicrobial activity against strains of Escherichia coli resistant to aminoglycosides. The growth of two bacterial strains of E. coli was tested using decocts and chlorpromazine alone or associeted with aminogycosides. Results The MIC and MBC values were ≥1024 μg/ml for both strains of E. coli assayed. A significant synergism was observed between both decocts and chlorpromazine when assyed with neomycin. This synergism with neomycin indicates the involvement of an efflux system in the resistance to this aminoglycoside. Conclusion Therefore it is suggested that natural products from N. corniger could be used as a source of zoo-derived natural products with modifying antibiotic activity to aminoglycosides, being a new weapon against the bacterial resistance to antibiotics.
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Targeting an antimicrobial effector function in insect immunity as a pest control strategy. Proc Natl Acad Sci U S A 2009; 106:12652-7. [PMID: 19506247 DOI: 10.1073/pnas.0904063106] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Insect pests such as termites cause damages to crops and man-made structures estimated at over $30 billion per year, imposing a global challenge for the human economy. Here, we report a strategy for compromising insect immunity that might lead to the development of nontoxic, sustainable pest control methods. Gram-negative bacteria binding proteins (GNBPs) are critical for sensing pathogenic infection and triggering effector responses. We report that termite GNBP-2 (tGNBP-2) shows beta(1,3)-glucanase effector activity previously unknown in animal immunity and is a pleiotropic pattern recognition receptor and an antimicrobial effector protein. Termites incorporate this protein into the nest building material, where it functions as a nest-embedded sensor that cleaves and releases pathogenic components, priming termites for improved antimicrobial defense. By means of rational design, we present an inexpensive, nontoxic small molecule glycomimetic that blocks tGNBP-2, thus exposing termites in vivo to accelerated infection and death from specific and opportunistic pathogens. Such a molecule, introduced into building materials and agricultural methods, could protect valuable assets from insect pests.
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