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Gang SS, Lažetić V. Microsporidia: Pervasive natural pathogens of Caenorhabditis elegans and related nematodes. J Eukaryot Microbiol 2024:e13027. [PMID: 38702921 DOI: 10.1111/jeu.13027] [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: 01/15/2024] [Accepted: 02/02/2024] [Indexed: 05/06/2024]
Abstract
The nematode Caenorhabditis elegans is an invaluable host model for studying infections caused by various pathogens, including microsporidia. Microsporidia represent the first natural pathogens identified in C. elegans, revealing the previously unknown Nematocida genus of microsporidia. Following this discovery, the utilization of nematodes as a model host has rapidly expanded our understanding of microsporidia biology and has provided key insights into the cell and molecular mechanisms of antimicrosporidia defenses. Here, we first review the isolation history, morphological characteristics, life cycles, tissue tropism, genetics, and host immune responses for the four most well-characterized Nematocida species that infect C. elegans. We then highlight additional examples of microsporidia that infect related terrestrial and aquatic nematodes, including parasitic nematodes. To conclude, we assess exciting potential applications of the nematode-microsporidia system while addressing the technical advances necessary to facilitate future growth in this field.
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Affiliation(s)
- Spencer S Gang
- Molecular Biology Department, Colorado College, Colorado Springs, Colorado, USA
| | - Vladimir Lažetić
- Department of Biological Sciences, Columbian College of Arts & Sciences, The George Washington University, Washington, District of Columbia, USA
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2
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González R, Félix MA. Caenorhabditis elegans immune responses to microsporidia and viruses. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 154:105148. [PMID: 38325500 DOI: 10.1016/j.dci.2024.105148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 01/30/2024] [Accepted: 02/03/2024] [Indexed: 02/09/2024]
Abstract
The model organism Caenorhabditis elegans is susceptible to infection by obligate intracellular pathogens, specifically microsporidia and viruses. These intracellular pathogens infect intestinal cells, or, for some microsporidia, epidermal cells. Strikingly, intestinal cell infections by viruses or microsporidia trigger a common transcriptional response, activated in part by the ZIP-1 transcription factor. Among the strongest activated genes in this response are ubiquitin-pathway members and members of the pals family, an intriguing gene family with cross-regulations of different members of genomic clusters. Some of the induced genes participate in host defense against the pathogens, for example through ubiquitin-mediated inhibition. Other mechanisms defend the host specifically against viral infections, including antiviral RNA interference and uridylation. These various immune responses are altered by environmental factors and by intraspecific genetic variation of the host. These pathogens were first isolated 15 years ago and much remains to be discovered using C. elegans genetics; also, other intracellular pathogens of C. elegans may yet to be discovered.
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Affiliation(s)
- Rubén González
- Institut de Biologie de l'École Normale Supérieure, CNRS, INSERM, 75005, Paris, France.
| | - Marie-Anne Félix
- Institut de Biologie de l'École Normale Supérieure, CNRS, INSERM, 75005, Paris, France
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3
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Trzebny A, Nahimova O, Dabert M. High temperatures and low humidity promote the occurrence of microsporidians (Microsporidia) in mosquitoes (Culicidae). Parasit Vectors 2024; 17:187. [PMID: 38605410 PMCID: PMC11008030 DOI: 10.1186/s13071-024-06254-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 03/20/2024] [Indexed: 04/13/2024] Open
Abstract
BACKGROUND In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing temperatures. In the present study, we used a mosquito-microsporidian model to determine the impact of environmental factors such as temperature, humidity, wind and rainfall on the occurrence rates of opportunistic obligate microparasites (Microsporidia) in hosts from a family that includes important disease vectors (Culicidae). METHODS In our study, 3000 adult mosquitoes collected from the field over 3 years were analysed. Mosquitoes and microsporidia were identified using PCR and sequencing of the hypervariable V5 region of the small subunit ribosomal RNA gene and a shortened fragment of the cytochrome c oxidase subunit I gene, respectively. RESULTS DNA metabarcoding was used to identify nine mosquito species, all of which were hosts of 12 microsporidian species. The prevalence of microsporidian DNA across all mosquito samples was 34.6%. Microsporidian prevalence in mosquitoes was more frequent during warm months (> 19 °C; humidity < 65%), as was the co-occurrence of two or three microsporidian species in a single host individual. During warm months, microsporidian occurrence was noted 1.6-fold more often than during the cold periods. Among the microsporidians found in the mosquitoes, five (representing the genera Enterocytospora, Vairimorpha and Microsporidium) were positively correlated with an increase in temperature, whereas one (Hazardia sp.) was significantly correlated with a decrease in temperature. Threefold more microsporidian co-occurrences were recorded in the warm months than in the cold months. CONCLUSIONS These results suggest that the susceptibility of mosquitoes to parasite occurrence is primarily determined by environmental conditions, such as, for example, temperatures > 19 °C and humidity not exceeding 62%. Collectively, our data provide a better understanding of the effects of the environment on microsporidian-mosquito interactions.
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Affiliation(s)
- Artur Trzebny
- Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland.
| | - Olena Nahimova
- Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
- Genetics and Cytology Department, School of Biology, V.N. Karazin Kharkiv National University, Kharkiv, Ukraine
| | - Miroslawa Dabert
- Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
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4
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Tersigni J, Tamim El Jarkass H, James EB, Reinke AW. Interactions between microsporidia and other members of the microbiome. J Eukaryot Microbiol 2024:e13025. [PMID: 38561869 DOI: 10.1111/jeu.13025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
The microbiome is the collection of microbes that are associated with a host. Microsporidia are intracellular eukaryotic parasites that can infect most types of animals. In the last decade, there has been much progress to define the relationship between microsporidia and the microbiome. In this review, we cover an increasing number of reports suggesting that microsporidia are common components of the microbiome in both invertebrates and vertebrates. These microsporidia infections can range from mutualistic to pathogenic, causing several physiological phenotypes, including death. Infection with microsporidia often causes a disruption in the normal microbiome, with both increases and decreases of bacterial, fungal, viral, and protozoan species being observed. This impact on the microbiome can occur through upregulation and downregulation of innate immunity as well as morphological changes to tissues that impact interactions with these microbes. Other microbes, particularly bacteria, can inhibit microsporidia and have been exploited to control microsporidia infections. These bacteria can function through regulating immunity, secreting anti-microsporidia compounds, and, in engineered versions, expressing double-stranded RNA targeting microsporidia genes. We end this review by discussing potential future directions to further understand the complex interactions between microsporidia and the other members of the microbiome.
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Affiliation(s)
- Jonathan Tersigni
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | | | - Edward B James
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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5
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Cooper JF, Nguyen K, Gates D, Wolfrum E, Capan C, Lee H, Williams D, Okoye C, Wojtovich AP, Burton NO. Oocyte mitochondria link maternal environment to offspring phenotype. RESEARCH SQUARE 2024:rs.3.rs-4087193. [PMID: 38585755 PMCID: PMC10996803 DOI: 10.21203/rs.3.rs-4087193/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
During maturation oocytes undergo a recently discovered mitochondrial proteome remodeling event in flies1, frogs1, and humans2. This oocyte mitochondrial remodeling, which includes substantial changes in electron transport chain (ETC) subunit abundance1,2, is regulated by maternal insulin signaling1. Why oocytes undergo mitochondrial remodeling is unknown, with some speculating that it might be an evolutionarily conserved mechanism to protect oocytes from genotoxic damage by reactive oxygen species (ROS)2. In Caenorhabditis elegans, we previously found that maternal exposure to osmotic stress drives a 50-fold increase in offspring survival in response to future osmotic stress3. Like mitochondrial remodeling, we found that this intergenerational adaptation is also regulated by insulin signaling to oocytes3. Here, we used proteomics and genetic manipulations to show that insulin signaling to oocytes regulates offspring's ability to adapt to future stress via a mechanism that depends on ETC composition in maternal oocytes. Specifically, we found that maternally expressed mutant alleles of nduf-7 (complex I subunit) or isp-1 (complex III subunit) altered offspring's response to osmotic stress at hatching independently of offspring genotype. Furthermore, we found that expressing wild-type isp-1 in germ cells (oocytes) was sufficient to restore offspring's normal response to osmotic stress. Chemical mutagenesis screens revealed that maternal ETC composition regulates offspring's response to stress by altering AMP kinase function in offspring which in turn regulates both ATP and glycerol metabolism in response to continued osmotic stress. To our knowledge, these data are the first to show that proper oocyte ETC composition is required to link a mother's environment to adaptive changes in offspring metabolism. The data also raise the possibility that the reason diverse animals exhibit insulin regulated remodeling of oocyte mitochondria is to tailor offspring metabolism to best match the environment of their mother.
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Affiliation(s)
- Jason F. Cooper
- Van Andel Research Institute, Department of Metabolism and Nutritional Programing, Grand Rapids, Michigan, USA, 49503
| | - Kim Nguyen
- Van Andel Research Institute, Department of Metabolism and Nutritional Programing, Grand Rapids, Michigan, USA, 49503
| | - Darrick Gates
- Van Andel Research Institute, Department of Metabolism and Nutritional Programing, Grand Rapids, Michigan, USA, 49503
| | - Emily Wolfrum
- Van Andel Research Institute, Grand Rapids, Michigan, USA, 49503
| | - Colt Capan
- Van Andel Research Institute, Grand Rapids, Michigan, USA, 49503
| | - Hyoungjoo Lee
- Van Andel Research Institute, Grand Rapids, Michigan, USA, 49503
| | - Devia Williams
- Van Andel Research Institute, Department of Metabolism and Nutritional Programing, Grand Rapids, Michigan, USA, 49503
| | - Chidozie Okoye
- University of Rochester Medical Center, Department of Anaesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Andrew P Wojtovich
- University of Rochester Medical Center, Department of Anaesthesiology and Perioperative Medicine, 575 Elmwood Ave., Rochester, NY, 14642, Box 711/604, USA
| | - Nicholas O. Burton
- Van Andel Research Institute, Department of Metabolism and Nutritional Programing, Grand Rapids, Michigan, USA, 49503
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6
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Sengupta T, St. Ange J, Kaletsky R, Moore RS, Seto RJ, Marogi J, Myhrvold C, Gitai Z, Murphy CT. A natural bacterial pathogen of C. elegans uses a small RNA to induce transgenerational inheritance of learned avoidance. PLoS Genet 2024; 20:e1011178. [PMID: 38547071 PMCID: PMC10977744 DOI: 10.1371/journal.pgen.1011178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/09/2024] [Indexed: 04/02/2024] Open
Abstract
C. elegans can learn to avoid pathogenic bacteria through several mechanisms, including bacterial small RNA-induced learned avoidance behavior, which can be inherited transgenerationally. Previously, we discovered that a small RNA from a clinical isolate of Pseudomonas aeruginosa, PA14, induces learned avoidance and transgenerational inheritance of that avoidance in C. elegans. Pseudomonas aeruginosa is an important human pathogen, and there are other Pseudomonads in C. elegans' natural habitat, but it is unclear whether C. elegans ever encounters PA14-like bacteria in the wild. Thus, it is not known if small RNAs from bacteria found in C. elegans' natural habitat can also regulate host behavior and produce heritable behavioral effects. Here we screened a set of wild habitat bacteria, and found that a pathogenic Pseudomonas vranovensis strain isolated from the C. elegans microbiota, GRb0427, regulates worm behavior: worms learn to avoid this pathogenic bacterium following exposure, and this learned avoidance is inherited for four generations. The learned response is entirely mediated by bacterially-produced small RNAs, which induce avoidance and transgenerational inheritance, providing further support that such mechanisms of learning and inheritance exist in the wild. We identified Pv1, a small RNA expressed in P. vranovensis, that has a 16-nucleotide match to an exon of the C. elegans gene maco-1. Pv1 is both necessary and sufficient to induce learned avoidance of Grb0427. However, Pv1 also results in avoidance of a beneficial microbiome strain, P. mendocina. Our findings suggest that bacterial small RNA-mediated regulation of host behavior and its transgenerational inheritance may be functional in C. elegans' natural environment, and that this potentially maladaptive response may favor reversal of the transgenerational memory after a few generations. Our data also suggest that different bacterial small RNA-mediated regulation systems evolved independently, but define shared molecular features of bacterial small RNAs that produce transgenerationally-inherited effects.
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Affiliation(s)
- Titas Sengupta
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Jonathan St. Ange
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Rachel Kaletsky
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Rebecca S. Moore
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Renee J. Seto
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Jacob Marogi
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Cameron Myhrvold
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Coleen T. Murphy
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
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7
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Tran TD, Luallen RJ. An organismal understanding of C. elegans innate immune responses, from pathogen recognition to multigenerational resistance. Semin Cell Dev Biol 2024; 154:77-84. [PMID: 36966075 PMCID: PMC10517082 DOI: 10.1016/j.semcdb.2023.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/05/2023] [Accepted: 03/14/2023] [Indexed: 03/27/2023]
Abstract
The nematode Caenorhabditis elegans has been a model for studying infection since the early 2000s and many major discoveries have been made regarding its innate immune responses. C. elegans has been found to utilize some key conserved aspects of immune responses and signaling, but new interesting features of innate immunity have also been discovered in the organism that might have broader implications in higher eukaryotes such as mammals. Some of the distinctive features of C. elegans innate immunity involve the mechanisms this bacterivore uses to detect infection and mount specific immune responses to different pathogens, despite lacking putative orthologs of many important innate immune components, including cellular immunity, the inflammasome, complement, or melanization. Even when orthologs of known immune factors exist, there appears to be an absence of canonical functions, most notably the lack of pattern recognition by its sole Toll-like receptor. Instead, recent research suggests that C. elegans senses infection by specific pathogens through contextual information, including unique products produced by the pathogen or infection-induced disruption of host physiology, similar to the proposed detection of patterns of pathogenesis in mammalian systems. Interestingly, C. elegans can also transfer information of past infection to their progeny, providing robust protection for their offspring in face of persisting pathogens, in part through the RNAi pathway as well as potential new mechanisms that remain to be elucidated. Altogether, some of these strategies employed by C. elegans share key conceptual features with vertebrate adaptive immunity, as the animal can differentiate specific microbial features, as well as propagate a form of immune memory to their offspring.
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Affiliation(s)
- Tuan D Tran
- Department of Biology San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
| | - Robert J Luallen
- Department of Biology San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA.
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8
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Huang Q, Chen J, Pan G, Reinke AW. Screening of the Pandemic Response Box identifies anti-microsporidia compounds. PLoS Negl Trop Dis 2023; 17:e0011806. [PMID: 38064503 PMCID: PMC10732440 DOI: 10.1371/journal.pntd.0011806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/20/2023] [Accepted: 11/20/2023] [Indexed: 12/21/2023] Open
Abstract
Microsporidia are fungal obligate intracellular pathogens, which infect most animals and cause microsporidiosis. Despite the serious threat that microsporidia pose to humans and agricultural animals, few drugs are available for the treatment and control of microsporidia. To identify novel inhibitors, we took advantage of the model organism Caenorhabditis elegans infected with its natural microsporidian Nematocida parisii. We used this system to screen the Pandemic Response Box, a collection of 400 diverse compounds with known antimicrobial activity. After testing these compounds in a 96-well format at high (100 μM) and low (40 μM) concentrations, we identified four inhibitors that restored the ability of C. elegans to produce progeny in the presence of N. parisii. All four compounds reduced the pathogen load of both N. parisii and Pancytospora epiphaga, a C. elegans-infecting microsporidia related to human-infecting species. One of these compounds, a known inhibitor of a viral protease, MMV1006203, inhibited invasion and prevented the firing of spores. A bis-indole derivative, MMV1593539, decreased spore viability. An albendazole analog, MMV1782387, inhibited proliferation of N. parisii. We tested albendazole as well as 5 other analogs and observed that MMV1782387 was amongst the strongest inhibitors of N. parisii and displayed the least host toxicity. Our study further demonstrates the effectiveness of the C. elegans-N. parisii system for discovering microsporidia inhibitors and the compounds we identified provide potential scaffolds for anti-microsporidia drug development.
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Affiliation(s)
- Qingyuan Huang
- State Key Laboratory of Resource Insects, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Jie Chen
- State Key Laboratory of Resource Insects, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Guoqing Pan
- State Key Laboratory of Resource Insects, Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
| | - Aaron W. Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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9
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Sengupta T, St. Ange J, Moore R, Kaletsky R, Marogi J, Myhrvold C, Gitai Z, Murphy CT. A natural bacterial pathogen of C. elegans uses a small RNA to induce transgenerational inheritance of learned avoidance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.20.549962. [PMID: 37503135 PMCID: PMC10370180 DOI: 10.1101/2023.07.20.549962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Previously, we discovered that a small RNA from a clinical isolate of Pseudomonas aeruginosa, PA14, induces learned avoidance and its transgenerational inheritance in C. elegans. Pseudomonas aeruginosa is an important human pathogen, and there are other Pseudomonads in C. elegans' natural habitat, but it is unclear whether C. elegans ever encounters PA14-like bacteria in the wild. Thus, it is not known if small RNAs from bacteria found in C. elegans' natural habitat can also regulate host behavior and produce heritable behavioral effects. Here we found that a pathogenic Pseudomonas vranovensis strain isolated from the C. elegans microbiota, GRb0427, like PA14, regulates worm behavior: worms learn to avoid this pathogenic bacterium following exposure to GRb0427, and this learned avoidance is inherited for four generations. The learned response is entirely mediated by bacterially-produced small RNAs, which induce avoidance and transgenerational inheritance, providing further support that such mechanisms of learning and inheritance exist in the wild. Using bacterial small RNA sequencing, we identified Pv1, a small RNA from GRb0427, that matches the sequence of C. elegans maco-1. We find that Pv1 is both necessary and sufficient to induce learned avoidance of Grb0427. However, Pv1 also results in avoidance of a beneficial microbiome strain, P. mendocina; this potentially maladaptive response may favor reversal of the transgenerational memory after a few generations. Our findings suggest that bacterial small RNA-mediated regulation of host behavior and its transgenerational inheritance are functional in C. elegans' natural environment, and that different bacterial small RNA-mediated regulation systems evolved independently but define shared molecular features of bacterial small RNAs that produce transgenerationally-inherited effects.
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Affiliation(s)
- Titas Sengupta
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jonathan St. Ange
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rebecca Moore
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rachel Kaletsky
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jacob Marogi
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Cameron Myhrvold
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Coleen T. Murphy
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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10
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Wadi L, El Jarkass HT, Tran TD, Islah N, Luallen RJ, Reinke AW. Genomic and phenotypic evolution of nematode-infecting microsporidia. PLoS Pathog 2023; 19:e1011510. [PMID: 37471459 PMCID: PMC10393165 DOI: 10.1371/journal.ppat.1011510] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 06/24/2023] [Indexed: 07/22/2023] Open
Abstract
Microsporidia are a large phylum of intracellular parasites that can infect most types of animals. Species in the Nematocida genus can infect nematodes including Caenorhabditis elegans, which has become an important model to study mechanisms of microsporidia infection. To understand the genomic properties and evolution of nematode-infecting microsporidia, we sequenced the genomes of nine species of microsporidia, including two genera, Enteropsectra and Pancytospora, without any previously sequenced genomes. Core cellular processes, including metabolic pathways, are mostly conserved across genera of nematode-infecting microsporidia. Each species encodes unique proteins belonging to large gene families that are likely used to interact with host cells. Most strikingly, we observed one such family, NemLGF1, is present in both Nematocida and Pancytospora species, but not any other microsporidia. To understand how Nematocida phenotypic traits evolved, we measured the host range, tissue specificity, spore size, and polar tube length of several species in the genus. Our phylogenetic analysis shows that Nematocida is composed of two groups of species with distinct traits and that species with longer polar tubes infect multiple tissues. Together, our work details both genomic and trait evolution between related microsporidia species and provides a useful resource for further understanding microsporidia evolution and infection mechanisms.
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Affiliation(s)
- Lina Wadi
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | | | - Tuan D Tran
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Nizar Islah
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Robert J Luallen
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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11
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Mok C, Xiao MA, Wan YC, Zhao W, Ahmed SM, Luallen RJ, Reinke AW. High-throughput phenotyping of infection by diverse microsporidia species reveals a wild C. elegans strain with opposing resistance and susceptibility traits. PLoS Pathog 2023; 19:e1011225. [PMID: 36893187 PMCID: PMC10030041 DOI: 10.1371/journal.ppat.1011225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 03/21/2023] [Accepted: 02/20/2023] [Indexed: 03/10/2023] Open
Abstract
Animals are under constant selective pressure from a myriad of diverse pathogens. Microsporidia are ubiquitous animal parasites, but the influence they exert on shaping animal genomes is mostly unknown. Using multiplexed competition assays, we measured the impact of four different species of microsporidia on 22 wild isolates of Caenorhabditis elegans. This resulted in the identification and confirmation of 13 strains with significantly altered population fitness profiles under infection conditions. One of these identified strains, JU1400, is sensitive to an epidermal-infecting species by lacking tolerance to infection. JU1400 is also resistant to an intestinal-infecting species and can specifically recognize and destroy this pathogen. Genetic mapping of JU1400 demonstrates that these two opposing phenotypes are caused by separate loci. Transcriptional analysis reveals the JU1400 sensitivity to epidermal microsporidia infection results in a response pattern that shares similarity to toxin-induced responses. In contrast, we do not observe JU1400 intestinal resistance being regulated at the transcriptional level. The transcriptional response to these four microsporidia species is conserved, with C. elegans strain-specific differences in potential immune genes. Together, our results show that phenotypic differences to microsporidia infection amongst C. elegans are common and that animals can evolve species-specific genetic interactions.
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Affiliation(s)
- Calvin Mok
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Meng A Xiao
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Yin C Wan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Winnie Zhao
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Shanzeh M Ahmed
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Robert J Luallen
- Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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12
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Wan YC, Troemel ER, Reinke AW. Conservation of Nematocida microsporidia gene expression and host response in Caenorhabditis nematodes. PLoS One 2022; 17:e0279103. [PMID: 36534656 PMCID: PMC9762603 DOI: 10.1371/journal.pone.0279103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Microsporidia are obligate intracellular parasites that are known to infect most types of animals. Many species of microsporidia can infect multiple related hosts, but it is not known if microsporidia express different genes depending upon which host species is infected or if the host response to infection is specific to each microsporidia species. To address these questions, we took advantage of two species of Nematocida microsporidia, N. parisii and N. ausubeli, that infect two species of Caenorhabditis nematodes, C. elegans and C. briggsae. We performed RNA-seq at several time points for each host infected with either microsporidia species. We observed that Nematocida transcription was largely independent of its host. We also observed that the host transcriptional response was similar when infected with either microsporidia species. Finally, we analyzed if the host response to microsporidia infection was conserved across host species. We observed that although many of the genes upregulated in response to infection are not direct orthologs, the same expanded gene families are upregulated in both Caenorhabditis hosts. Together our results describe the transcriptional interactions of Nematocida infection in Caenorhabditis hosts and demonstrate that these responses are evolutionarily conserved.
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Affiliation(s)
- Yin Chen Wan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Aaron W. Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada,* E-mail:
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13
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Gang SS, Grover M, Reddy KC, Raman D, Chang YT, Ekiert DC, Barkoulas M, Troemel ER. A pals-25 gain-of-function allele triggers systemic resistance against natural pathogens of C. elegans. PLoS Genet 2022; 18:e1010314. [PMID: 36191002 PMCID: PMC9560605 DOI: 10.1371/journal.pgen.1010314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/13/2022] [Accepted: 09/15/2022] [Indexed: 11/15/2022] Open
Abstract
Regulation of immunity throughout an organism is critical for host defense. Previous studies in the nematode Caenorhabditis elegans have described an "ON/OFF" immune switch comprised of the antagonistic paralogs PALS-25 and PALS-22, which regulate resistance against intestinal and epidermal pathogens. Here, we identify and characterize a PALS-25 gain-of-function mutant protein with a premature stop (Q293*), which we find is freed from physical repression by its negative regulator, the PALS-22 protein. PALS-25(Q293*) activates two related gene expression programs, the Oomycete Recognition Response (ORR) against natural pathogens of the epidermis, and the Intracellular Pathogen Response (IPR) against natural intracellular pathogens of the intestine. A subset of ORR/IPR genes is upregulated in pals-25(Q293*) mutants, and they are resistant to oomycete infection in the epidermis, and microsporidia and virus infection in the intestine, but without compromising growth. Surprisingly, we find that activation of PALS-25 seems to primarily stimulate the downstream bZIP transcription factor ZIP-1 in the epidermis, with upregulation of gene expression in both the epidermis and in the intestine. Interestingly, we find that PALS-22/25-regulated epidermal-to-intestinal signaling promotes resistance to the N. parisii intestinal pathogen, demonstrating cross-tissue protective immune induction from one epithelial tissue to another in C. elegans.
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Affiliation(s)
- Spencer S. Gang
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Manish Grover
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Kirthi C. Reddy
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Deevya Raman
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ya-Ting Chang
- Departments of Cell Biology and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Damian C. Ekiert
- Departments of Cell Biology and Microbiology, New York University School of Medicine, New York, New York, United States of America
| | | | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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14
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High-throughput small molecule screen identifies inhibitors of microsporidia invasion and proliferation in C. elegans. Nat Commun 2022; 13:5653. [PMID: 36163337 PMCID: PMC9513054 DOI: 10.1038/s41467-022-33400-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/15/2022] [Indexed: 01/19/2023] Open
Abstract
Microsporidia are a diverse group of fungal-related obligate intracellular parasites that infect most animal phyla. Despite the emerging threat that microsporidia represent to humans and agricultural animals, few reliable treatment options exist. Here, we develop a high-throughput screening method for the identification of chemical inhibitors of microsporidia infection, using liquid cultures of Caenorhabditis elegans infected with the microsporidia species Nematocida parisii. We screen a collection of 2560 FDA-approved compounds and natural products, and identify 11 candidate microsporidia inhibitors. Five compounds prevent microsporidia infection by inhibiting spore firing, whereas one compound, dexrazoxane, slows infection progression. The compounds have in vitro activity against several other microsporidia species, including those known to infect humans. Together, our results highlight the effectiveness of C. elegans as a model host for drug discovery against intracellular pathogens, and provide a scalable high-throughput system for the identification and characterization of microsporidia inhibitors.
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15
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Rivera DE, Lažetić V, Troemel ER, Luallen RJ. RNA Fluorescence in situ Hybridization (FISH) to Visualize Microbial Colonization and Infection in Caenorhabditis elegans Intestines. J Vis Exp 2022:10.3791/63980. [PMID: 35969095 PMCID: PMC9969837 DOI: 10.3791/63980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The intestines of wild Caenorhabditis nematodes are inhabited by a variety of microorganisms, including gut microbiome bacteria and pathogens, such as microsporidia and viruses. Because of the similarities between Caenorhabditis elegans and mammalian intestinal cells, as well as the power of the C. elegans system, this host has emerged as a model system to study host intestine-microbe interactions in vivo. While it is possible to observe some aspects of these interactions with bright-field microscopy, it is difficult to accurately classify microbes and characterize the extent of colonization or infection without more precise tools. RNA fluorescence in situ hybridization (FISH) can be used as a tool to identify and visualize microbes in nematodes from the wild or to experimentally characterize and quantify infection in nematodes infected with microbes in the lab. FISH probes, labeling the highly abundant small subunit ribosomal RNA, produce a bright signal for bacteria and microsporidian cells. Probes designed to target conserved regions of ribosomal RNA common to many species can detect a broad range of microbes, whereas targeting divergent regions of the ribosomal RNA is useful for narrower detection. Similarly, probes can be designed to label viral RNA. A protocol for RNA FISH staining with either paraformaldehyde (PFA) or acetone fixation is presented. PFA fixation is ideal for nematodes associated with bacteria, microsporidia, and viruses, whereas acetone fixation is necessary for the visualization of microsporida spores. Animals were first washed and fixed in paraformaldehyde or acetone. After fixation, FISH probes were incubated with samples to allow for the hybridization of probes to the desired target. The animals were again washed and then examined on microscope slides or using automated approaches. Overall, this FISH protocol enables detection, identification, and quantification of the microbes that inhabit the C. elegans intestine, including microbes for which there are no genetic tools available.
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Affiliation(s)
| | - Vladimir Lažetić
- School of Biological Sciences, University of California, San Diego
| | - Emily R. Troemel
- School of Biological Sciences, University of California, San Diego
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16
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Bubrig LT, Janisch AN, Tillet EM, Gibson AK. Contrasting parasite-mediated reductions in fitness within versus between patches of a nematode host. Evolution 2022; 76:1556-1564. [PMID: 35652582 PMCID: PMC9329228 DOI: 10.1111/evo.14521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 01/22/2023]
Abstract
Host and parasites interact across spatial scales, but parasite-mediated fitness effects are typically measured only at local scales. Recent work suggests that parasites can reduce host fitness during dispersal between patches, highlighting the potential for both within- and between-patch effects to contribute to the net fitness consequences of parasitism. Building on this work, we measured the contribution of the dispersal phase to parasite-mediated reductions in host fitness. We used the nematode Caenorhabditis elegans and its natural microsporidian parasite Nematocida parisii to quantify the fitness consequences of parasitism at the individual, population, and metapopulation level. Nematocida parisii reduced individual fecundity and population growth but had its greatest fitness impact at the dispersal stage: parasitism reduced the fitness of dispersing larvae by 62%-100%. These results indicate that the cost of parasitism in this system is greatly underestimated if the metapopulation level is not taken into account. We also found that the effects of N. parisii vary with host genotype, and the relative advantage of the most resistant genotype increases with inclusion of the dispersal stage. Taken together, our findings demonstrate that host-parasite interactions at the dispersal stage can magnify selection for parasite resistance.
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Affiliation(s)
- Louis T. Bubrig
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginia22904
| | - Anne N. Janisch
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginia22904
| | - Emily M. Tillet
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginia22904
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17
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Tran TD, Ali MA, Lee D, Félix MA, Luallen RJ. Bacterial filamentation as a mechanism for cell-to-cell spread within an animal host. Nat Commun 2022; 13:693. [PMID: 35121734 PMCID: PMC8816909 DOI: 10.1038/s41467-022-28297-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 01/14/2022] [Indexed: 01/01/2023] Open
Abstract
Intracellular pathogens are challenged with limited space and resources while replicating in a single host cell. Mechanisms for direct invasion of neighboring host cells have been discovered in cell culture, but we lack an understanding of how bacteria directly spread between host cells in vivo. Here, we describe the discovery of intracellular bacteria that use filamentation for spreading between the intestinal epithelial cells of a natural host, the rhabditid nematode Oscheius tipulae. The bacteria, which belong to the new species Bordetella atropi, can infect the nematodes following a fecal-oral route, and reduce host life span and fecundity. Filamentation requires UDP-glucose biosynthesis and sensing, a highly conserved pathway that is used by other bacteria to detect rich conditions and inhibit cell division. Our results indicate that B. atropi uses a pathway that normally regulates bacterial cell size to trigger filamentation inside host cells, thus facilitating cell-to-cell dissemination. Some intracellular pathogens can directly invade neighboring host cells in cell culture, but it is unclear how this happens in vivo. Here, Tran et al. describe an intracellular bacterium that forms filaments to spread between intestinal epithelial cells in its host nematode, in a process regulated by a conserved nutrient-sensing pathway.
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18
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Tamim El Jarkass H, Mok C, Schertzberg MR, Fraser AG, Troemel ER, Reinke AW. An intestinally secreted host factor promotes microsporidia invasion of C. elegans. eLife 2022; 11:72458. [PMID: 34994689 PMCID: PMC8806185 DOI: 10.7554/elife.72458] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/06/2022] [Indexed: 12/11/2022] Open
Abstract
Microsporidia are ubiquitous obligate intracellular pathogens of animals. These parasites often infect hosts through an oral route, but little is known about the function of host intestinal proteins that facilitate microsporidia invasion. To identify such factors necessary for infection by Nematocida parisii, a natural microsporidian pathogen of Caenorhabditis elegans, we performed a forward genetic screen to identify mutant animals that have a Fitness Advantage with Nematocida (Fawn). We isolated four fawn mutants that are resistant to Nematocida infection and contain mutations in T14E8.4, which we renamed aaim-1 (Antibacterial and Aids invasion by Microsporidia). Expression of AAIM-1 in the intestine of aaim-1 animals restores N. parisii infectivity and this rescue of infectivity is dependent upon AAIM-1 secretion. N. parisii spores in aaim-1 animals are improperly oriented in the intestinal lumen, leading to reduced levels of parasite invasion. Conversely, aaim-1 mutants display both increased colonization and susceptibility to the bacterial pathogen Pseudomonas aeruginosa and overexpression ofaaim-1 reduces P. aeruginosa colonization. Competitive fitness assays show that aaim-1 mutants are favored in the presence of N. parisii but disadvantaged on P. aeruginosa compared to wild-type animals. Together, this work demonstrates how microsporidia exploits a secreted protein to promote host invasion. Our results also suggest evolutionary trade-offs may exist to optimizing host defense against multiple classes of pathogens.
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Affiliation(s)
| | - Calvin Mok
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | | | - Andrew G Fraser
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Emily R Troemel
- Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
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19
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Willis AR, Reinke AW. Factors That Determine Microsporidia Infection and Host Specificity. EXPERIENTIA SUPPLEMENTUM (2012) 2022; 114:91-114. [PMID: 35544000 DOI: 10.1007/978-3-030-93306-7_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microsporidia are a large phylum of obligate intracellular parasites that infect an extremely diverse range of animals and protists. In this chapter, we review what is currently known about microsporidia host specificity and what factors influence microsporidia infection. Extensive sampling in nature from related hosts has provided insight into the host range of many microsporidia species. These field studies have been supported by experiments conducted in controlled laboratory environments which have helped to demonstrate host specificity. Together, these approaches have revealed that, while examples of generalist species exist, microsporidia specificity is often narrow, and species typically infect one or several closely related hosts. For microsporidia to successfully infect and complete their life cycle within a compatible host, several steps must occur, including spore germination, host cell invasion, and proliferation of the parasite within the host tissue. Many factors influence infection, including temperature, seasonality, nutrient availability, and the presence or absence of microbes, as well as the developmental stage, sex, and genetics of the host. Several studies have identified host genomic regions that influence resistance to microsporidia, and future work is likely to uncover molecular mechanisms of microsporidia host specificity in more detail.
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Affiliation(s)
- Alexandra R Willis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Aaron W Reinke
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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20
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Insights from C. elegans into Microsporidia Biology and Host-Pathogen Relationships. EXPERIENTIA SUPPLEMENTUM 2022; 114:115-136. [PMID: 35544001 PMCID: PMC9208714 DOI: 10.1007/978-3-030-93306-7_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Microsporidia are poorly understood, ubiquitous eukaryotic parasites that are completely dependent on their hosts for replication. With the discovery of microsporidia species naturally infecting the genetically tractable transparent nematode C. elegans, this host has been used to explore multiple areas of microsporidia biology. Here we review results about microsporidia infections in C. elegans, which began with the discovery of the intestinal-infecting species Nematocida parisii. Recent findings include new species identification in the Nematocida genus, with more intestinal-infecting species, and also a species with broader tissue tropism, the epidermal and muscle-infecting species Nematocida displodere. This species has a longer polar tube infection apparatus, which may enable its wider tissue range. After invasion, multiple Nematocida species appear to fuse host cells, which likely promotes their dissemination within host organs. Localized proteomics identified Nematocida proteins that have direct contact with the C. elegans intestinal cytosol and nucleus, and many of these host-exposed proteins belong to expanded, species-specific gene families. On the host side, forward genetic screens have identified regulators of the Intracellular Pathogen Response (IPR), which is a transcriptional response induced by both microsporidia and the Orsay virus, which is also a natural, obligate intracellular pathogen of the C. elegans intestine. The IPR constitutes a novel immune/stress response that promotes resistance against microsporidia, virus, and heat shock. Overall, the Nematocida/C. elegans system has provided insights about strategies for microsporidia pathogenesis, as well as innate defense pathways against these parasites.
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21
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Molecular insights into transgenerational inheritance of stress memory. J Genet Genomics 2021; 49:89-95. [PMID: 34923165 DOI: 10.1016/j.jgg.2021.11.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 11/23/2022]
Abstract
There is accumulating evidence to show that environmental stressors can regulate a variety of phenotypes in descendants through germline-mediated epigenetic inheritance. Studies of model organisms exposed to environmental cues (e.g., diet, heat stress, toxins) indicate that altered DNA methylations, histone modifications, or non-coding RNAs in the germ cells are responsible for the transgenerational effects. In addition, it has also become evident that maternal provision could provide a mechanism for the transgenerational inheritance of stress adaptations that result from ancestral environmental cues. However, how the signal of environmentally-induced stress response transmits from the soma to the germline, which may influence offspring fitness, remains largely elusive. Small RNAs could serve as signaling molecules that transmit between tissues and even across generations. Furthermore, a recent study revealed that neuronal mitochondrial perturbations induce a transgenerational induction of the mitochondrial unfolded protein response mediated by a Wnt-dependent increase in mitochondrial DNA levels. Here, we review recent work on the molecular mechanism by which parental experience can affect future generations and the importance of soma-to-germline signaling for transgenerational inheritance.
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22
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An integrated view of innate immune mechanisms in C. elegans. Biochem Soc Trans 2021; 49:2307-2317. [PMID: 34623403 DOI: 10.1042/bst20210399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 12/13/2022]
Abstract
The simple notion 'infection causes an immune response' is being progressively refined as it becomes clear that immune mechanisms cannot be understood in isolation, but need to be considered in a more global context with other cellular and physiological processes. In part, this reflects the deployment by pathogens of virulence factors that target diverse cellular processes, such as translation or mitochondrial respiration, often with great molecular specificity. It also reflects molecular cross-talk between a broad range of host signalling pathways. Studies with the model animal C. elegans have uncovered a range of examples wherein innate immune responses are intimately connected with different homeostatic mechanisms, and can influence reproduction, ageing and neurodegeneration, as well as various other aspects of its biology. Here we provide a short overview of a number of such connections, highlighting recent discoveries that further the construction of a fully integrated view of innate immunity.
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23
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Burton NO, Willis A, Fisher K, Braukmann F, Price J, Stevens L, Baugh LR, Reinke A, Miska EA. Intergenerational adaptations to stress are evolutionarily conserved, stress-specific, and have deleterious trade-offs. eLife 2021; 10:e73425. [PMID: 34622777 PMCID: PMC8570697 DOI: 10.7554/elife.73425] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/27/2021] [Indexed: 12/24/2022] Open
Abstract
Despite reports of parental exposure to stress promoting physiological adaptations in progeny in diverse organisms, there remains considerable debate over the significance and evolutionary conservation of such multigenerational effects. Here, we investigate four independent models of intergenerational adaptations to stress in Caenorhabditis elegans - bacterial infection, eukaryotic infection, osmotic stress, and nutrient stress - across multiple species. We found that all four intergenerational physiological adaptations are conserved in at least one other species, that they are stress -specific, and that they have deleterious tradeoffs in mismatched environments. By profiling the effects of parental bacterial infection and osmotic stress exposure on progeny gene expression across species, we established a core set of 587 genes that exhibited a greater than twofold intergenerational change in expression in response to stress in C. elegans and at least one other species, as well as a set of 37 highly conserved genes that exhibited a greater than twofold intergenerational change in expression in all four species tested. Furthermore, we provide evidence suggesting that presumed adaptive and deleterious intergenerational effects are molecularly related at the gene expression level. Lastly, we found that none of the effects we detected of these stresses on C. elegans F1 progeny gene expression persisted transgenerationally three generations after stress exposure. We conclude that intergenerational responses to stress play a substantial and evolutionarily conserved role in regulating animal physiology and that the vast majority of the effects of parental stress on progeny gene expression are reversible and not maintained transgenerationally.
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Affiliation(s)
- Nicholas O Burton
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of CambridgeCambridgeUnited Kingdom
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
- Van Andel InstituteGrand RapidsUnited States
| | - Alexandra Willis
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Kinsey Fisher
- Department of Biology, Duke UniversityDurhamUnited States
| | - Fabian Braukmann
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
| | - Jonathan Price
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
| | - Lewis Stevens
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States
- Wellcome Sanger Institute, Wellcome Genome CampusCambridgeUnited Kingdom
| | - L Ryan Baugh
- Department of Biology, Duke UniversityDurhamUnited States
- Center for Genomic and Computational Biology, Duke UniversityDurhamUnited States
| | - Aaron Reinke
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Eric A Miska
- Gurdon Institute, University of CambridgeCambridgeUnited Kingdom
- Wellcome Sanger Institute, Wellcome Genome CampusCambridgeUnited Kingdom
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
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24
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Burton NO, Greer EL. Multigenerational epigenetic inheritance: Transmitting information across generations. Semin Cell Dev Biol 2021; 127:121-132. [PMID: 34426067 DOI: 10.1016/j.semcdb.2021.08.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 01/07/2023]
Abstract
Inherited epigenetic information has been observed to regulate a variety of complex organismal phenotypes across diverse taxa of life. This continually expanding body of literature suggests that epigenetic inheritance plays a significant, and potentially fundamental, role in inheritance. Despite the important role these types of effects play in biology, the molecular mediators of this non-genetic transmission of information are just now beginning to be deciphered. Here we provide an intellectual framework for interpreting these findings and how they can interact with each other. We also define the different types of mechanisms that have been found to mediate epigenetic inheritance and to regulate whether epigenetic information persists for one or many generations. The field of epigenetic inheritance is entering an exciting phase, in which we are beginning to understand the mechanisms by which non-genetic information is transmitted to, and deciphered by, subsequent generations to maintain essential environmental information without permanently altering the genetic code. A more complete understanding of how and when epigenetic inheritance occurs will advance our understanding of numerous different aspects of biology ranging from how organisms cope with changing environments to human pathologies influenced by a parent's environment.
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Affiliation(s)
- Nicholas O Burton
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK; Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, UK; Center for Epigenetics, Van Andel Institute, Grand Rapids, MI 49503, USA.
| | - Eric L Greer
- Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Medical School Initiative for RNA Medicine, Boston, MA 02115, USA.
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