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Dziuba MK, McIntire KM, Seto K, Davenport ES, Rogalski MA, Gowler CD, Baird E, Vaandrager M, Huerta C, Jaye R, Corcoran FE, Withrow A, Ahrendt S, Salamov A, Nolan M, Tejomurthula S, Barry K, Grigoriev IV, James TY, Duffy MA. Phylogeny, morphology, virulence, ecology, and host range of Ordospora pajunii (Ordosporidae), a microsporidian symbiont of Daphnia spp. mBio 2024; 15:e0058224. [PMID: 38651867 DOI: 10.1128/mbio.00582-24] [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: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024] Open
Abstract
The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered microsporidian symbiont of Daphnia, the net impact of which was found to shift from negative to positive based on environmental context. Given this, we hypothesized low baseline virulence of the microsporidian; here, we investigated the impact of infection on hosts in controlled conditions and the absence of other stressors. We also investigated its phylogenetic position, ecology, and host range. The genetic data indicate that the symbiont is Ordospora pajunii, a newly described microsporidian parasite of Daphnia. We show that O. pajunii infection damages the gut, causing infected epithelial cells to lose microvilli and then rupture. The prevalence of this microsporidian could be high (up to 100% in the lab and 77% of adults in the field). Its overall virulence was low in most cases, but some genotypes suffered reduced survival and/or reproduction. Susceptibility and virulence were strongly host-genotype dependent. We found that North American O. pajunii were able to infect multiple Daphnia species, including the European species Daphnia longispina, as well as Ceriodaphnia spp. Given the low, often undetectable virulence of this microsporidian and potentially far-reaching consequences of infections for the host when interacting with other pathogens or food, this Daphnia-O. pajunii symbiosis emerges as a valuable system for studying the mechanisms of context-dependent shifts between mutualism and parasitism, as well as for understanding how symbionts might alter host interactions with resources. IMPORTANCE The net outcome of symbiosis depends on the costs and benefits to each partner. Those can be context dependent, driving the potential for an interaction to change between parasitism and mutualism. Understanding the baseline fitness impact in an interaction can help us understand those shifts; for an organism that is generally parasitic, it should be easier for it to become a mutualist if its baseline virulence is relatively low. Recently, a microsporidian was found to become beneficial to its Daphnia hosts in certain ecological contexts, but little was known about the symbiont (including its species identity). Here, we identify it as the microsporidium Ordospora pajunii. Despite the parasitic nature of microsporidia, we found O. pajunii to be, at most, mildly virulent; this helps explain why it can shift toward mutualism in certain ecological contexts and helps establish O. pajunii is a valuable model for investigating shifts along the mutualism-parasitism continuum.
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Affiliation(s)
- Marcin K Dziuba
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kristina M McIntire
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kensuke Seto
- Faculty of Environment and Information Sciences, Yokohama National University, Yokohama, Kanagawa, Japan
| | - Elizabeth S Davenport
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mary A Rogalski
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
- Biology Department, Bowdoin College, Brunswick, Maine, USA
| | - Camden D Gowler
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Emma Baird
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Megan Vaandrager
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Cristian Huerta
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Riley Jaye
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Fiona E Corcoran
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alicia Withrow
- Center for Advanced Microscopy, Michigan State University, East Lansing, Michigan, USA
| | - Steven Ahrendt
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Asaf Salamov
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Matt Nolan
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Sravanthi Tejomurthula
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Kerrie Barry
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Igor V Grigoriev
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Timothy Y James
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Meghan A Duffy
- Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
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Timanikova N, Fletcher K, Han JW, van West P, Woodward S, Kim GH, Küpper FC, Wenzel M. Macroalgal eukaryotic microbiome composition indicates novel phylogenetic diversity and broad host spectrum of oomycete pathogens. Environ Microbiol 2024; 26:e16656. [PMID: 38818657 DOI: 10.1111/1462-2920.16656] [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: 12/01/2023] [Accepted: 05/07/2024] [Indexed: 06/01/2024]
Abstract
Seaweeds are important components of marine ecosystems with emerging potential in aquaculture and as sources of biofuel, food products and pharmacological compounds. However, an increasingly recognised threat to natural and industrial seaweed populations is infection with parasitic single-celled eukaryotes from the relatively understudied oomycete lineage. Here we examine the eukaryomes of diverse brown, red and green marine macroalgae collected from polar (Baffin Island), cold-temperate (Falkland Islands) and tropical (Ascension Island) locations, with a focus on oomycete and closely related diatom taxa. Using 18S rRNA gene amplicon sequencing, we show unexpected genetic and taxonomic diversity of the eukaryomes, a strong broad-brush association between eukaryome composition and geographic location, and some evidence of association between eukaryome structure and macroalgal phylogenetic relationships (phylosymbiosis). However, the oomycete fraction of the eukaryome showed disparate patterns of diversity and structure, highlighting much weaker association with geography and no evidence of phylosymbiosis. We present several novel haplotypes of the most common oomycete Eurychasma dicksonii and report for the first time a cosmopolitan distribution and absence of host specificity of this important pathogen. This indicates rich diversity in macroalgal oomycete pathogens and highlights that these pathogens may be generalist and highly adaptable to diverse environmental conditions.
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Affiliation(s)
| | - Kyle Fletcher
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- Oceanlab, University of Aberdeen, Newburgh, UK
- Aberdeen Oomycete Laboratory, International Centre for Aquaculture Research and Development, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Jon-Wong Han
- Kongju National University, Gongju, South Chungcheong Province, South Korea
| | - Pieter van West
- Aberdeen Oomycete Laboratory, International Centre for Aquaculture Research and Development, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Steve Woodward
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Gwang-Hoon Kim
- Kongju National University, Gongju, South Chungcheong Province, South Korea
| | - Frithjof C Küpper
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- Kongju National University, Gongju, South Chungcheong Province, South Korea
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen, UK
- Department of Chemistry and Biochemistry, San Diego State University, California, San Diego, California, USA
| | - Marius Wenzel
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
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3
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Davenport ES, Dziuba MK, Jacobson LE, Calhoun SK, Monell KJ, Duffy MA. How does parasite environmental transmission stage concentration change before, during, and after disease outbreaks? Ecology 2024; 105:e4235. [PMID: 38185479 DOI: 10.1002/ecy.4235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/09/2023] [Indexed: 01/09/2024]
Abstract
Outbreaks of environmentally transmitted parasites require that susceptible hosts encounter transmission stages in the environment and become infected, but we also know that transmission stages can be in the environment without triggering disease outbreaks. One challenge in understanding the relationship between environmental transmission stages and disease outbreaks is that the distribution and abundance of transmission stages outside of their hosts have been difficult to quantify. Thus, we have limited data about how changes in transmission stage abundance influence disease dynamics; moreover, we do not know whether the relationship between transmission stages and outbreaks differs among parasite species. We used digital PCR to quantify the environmental transmission stages of five parasites in six lakes in southeastern Michigan every 2 weeks from June to November 2021. At the same time, we quantified infection prevalence in hosts and host density. Our study focused on eight zooplankton host species (Daphnia spp. and Ceriodaphnia dubia) and five of their parasites from diverse taxonomic groups (bacteria, yeast, microsporidia, and oomycete) with different infection mechanisms. We found that parasite transmission stage concentration increased prior to disease outbreaks for all parasites. However, parasites differed significantly in the relative timing of peaks in transmission stage concentration and infection outbreaks. The "continuous shedder" parasites had transmission stage peaks at the same time as or slightly after the outbreak peaks. In contrast, parasites relying on host death for transmission ("obligate killers") had transmission stage peaks before outbreak peaks. For most parasites, lakes with outbreaks had higher spore concentrations than those without outbreaks, especially once an outbreak began; the exception was for a parasite, Pasteuria ramosa, with very strong genotypic specificity of infection. Overall, our results show that disease outbreaks are tightly linked to transmission stage concentration; outbreaks were preceded by increases in transmission stage concentration in the environment and then were fueled by the production of more transmission stages during the outbreak itself, with concentrations decreasing to pre-outbreak levels as outbreaks waned. Thus, tracking transmission stages in the environment improves our understanding of the drivers of disease outbreaks and reveals how parasite traits may affect these dynamics.
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Affiliation(s)
- Elizabeth S Davenport
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Marcin K Dziuba
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Logan E Jacobson
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Siobhan K Calhoun
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kira J Monell
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Meghan A Duffy
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
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Strauss AT, Suh DC, Galbraith K, Coker SM, Schroeder K, Brandon C, Warburton EM, Yabsley MJ, Cleveland CA. Mysterious microsporidians: springtime outbreaks of disease in Daphnia communities in shallow pond ecosystems. Oecologia 2024; 204:303-314. [PMID: 37470872 DOI: 10.1007/s00442-023-05421-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 07/09/2023] [Indexed: 07/21/2023]
Abstract
Parasites can play key roles in ecosystems, especially when they infect common hosts that play important ecological roles. Daphnia are critical grazers in many lentic freshwater ecosystems and typically reach peak densities in early spring. Daphnia have also become prominent model host organisms for the field of disease ecology, although most well-studied parasites infect them in summer or fall. Here, we report field patterns of virulent microsporidian parasites that consistently infect Daphnia in springtime, in a set of seven shallow ponds in Georgia, USA, sampled every 3-4 weeks for 18 months. We detected two distinct parasite taxa, closely matching sequences of Pseudoberwaldia daphniae and Conglomerata obtusa, both infecting all three resident species of Daphnia: D. ambigua, D. laevis, and D. parvula. To our knowledge, neither parasite has been previously reported in any of these host species or anywhere in North America. Infection prevalence peaked consistently in February-May, but the severity of these outbreaks differed substantially among ponds. Moreover, host species differed markedly in terms of their maximum infection prevalence (5% [D. parvula] to 72% [D. laevis]), mean reduction of fecundity when infected (70.6% [D. ambigua] to 99.8% [D. laevis]), mean spore yield (62,000 [D. parvula] to 377,000 [D. laevis] per host), and likelihood of being infected by each parasite. The timing and severity of the outbreaks suggests that these parasites could be impactful members of these shallow freshwater ecosystems, and that the strength of their effects is likely to hinge on the composition of ponds' zooplankton communities.
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Affiliation(s)
- Alexander T Strauss
- Odum School of Ecology, University of Georgia, Athens, GA, USA.
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
- River Basin Center, University of Georgia, Athens, GA, USA.
| | - Daniel C Suh
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Kate Galbraith
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Sarah M Coker
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Katie Schroeder
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | | | - Elizabeth M Warburton
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Michael J Yabsley
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
| | - Christopher A Cleveland
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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5
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Corsaro D. Insights into Microsporidia Evolution from Early Diverging Microsporidia. EXPERIENTIA SUPPLEMENTUM (2012) 2022; 114:71-90. [PMID: 35543999 DOI: 10.1007/978-3-030-93306-7_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Microsporidia have drastically modified genomes and cytology resulting from their high level of adaptation to intracytoplasmic parasitism. Their origins, which had long remained enigmatic, were placed within the line of Rozella, a primitive endoparasitic chytrid. These origins became more and more refined with the discovery of various parasites morphologically similar to the primitive lines of microsporidia (Metchnikovellids and Chytridiopsids) but which possess fungal-like genomes and functional mitochondria. These various parasites turn out to be distinct missing links between a large assemblage of chytrid-like rozellids and the true microsporidians, which are actually a very evolved branch of the rozellids themselves. The question of how to consider the historically known Microsporidia and the various microsporidia-like organisms within paraphyletic rozellids is discussed.
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Affiliation(s)
- Daniele Corsaro
- CHLAREAS Chlamydia Research Association, Vandoeuvre-lès-Nancy, France.
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Rogalski MA, Stewart Merrill T, Gowler CD, Cáceres CE, Duffy MA. Context-Dependent Host-Symbiont Interactions: Shifts along the Parasitism-Mutualism Continuum. Am Nat 2021; 198:563-575. [PMID: 34648395 DOI: 10.1086/716635] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractSymbiotic interactions can shift along a mutualism-parasitism continuum. While there are many studies examining dynamics typically considered to be mutualistic that sometimes shift toward parasitism, little is known about conditions underlying shifts from parasitism toward mutualism. In lake populations, we observed that infection by a microsporidian gut symbiont sometimes conferred a reproductive advantage and other times a disadvantage to its Daphnia host. We hypothesized that the microsporidian might benefit its host by reducing infection by more virulent parasites, which attack via the gut. In a laboratory study using field-collected animals, we found that spores of a virulent fungal parasite were much less capable of penetrating the guts of Daphnia harboring the microsporidian gut symbiont. We predicted that this altered gut penetrability could cause differential impacts on host fitness depending on ecological context. Field survey data revealed that microsporidian-infected Daphnia hosts experienced a reproductive advantage when virulent parasites were common while resource scarcity led to a reproductive disadvantage, but only in lakes where virulent parasites were relatively rare. Our findings highlight the importance of considering multiparasite community context and resource availability in host-parasite studies and open the door for future research into conditions driving shifts along parasitism to mutualism gradients.
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Gowler CD, Rogalski MA, Shaw CL, Hunsberger KK, Duffy MA. Density, parasitism, and sexual reproduction are strongly correlated in lake Daphnia populations. Ecol Evol 2021; 11:10446-10456. [PMID: 34367587 PMCID: PMC8328469 DOI: 10.1002/ece3.7847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/03/2021] [Accepted: 06/08/2021] [Indexed: 01/06/2023] Open
Abstract
Many organisms can reproduce both asexually and sexually. For cyclical parthenogens, periods of asexual reproduction are punctuated by bouts of sexual reproduction, and the shift from asexual to sexual reproduction has large impacts on fitness and population dynamics. We studied populations of Daphnia dentifera to determine the amount of investment in sexual reproduction as well as the factors associated with variation in investment in sex. To do so, we tracked host density, infections by nine different parasites, and sexual reproduction in 15 lake populations of D. dentifera for 3 years. Sexual reproduction was seasonal, with male and ephippial female production beginning as early as late September and generally increasing through November. However, there was substantial variation in the prevalence of sexual individuals across populations, with some populations remaining entirely asexual throughout the study period and others shifting almost entirely to sexual females and males. We found strong relationships between density, prevalence of infection, parasite species richness, and sexual reproduction in these populations. However, strong collinearity between density, parasitism, and sexual reproduction means that further work will be required to disentangle the causal mechanisms underlying these relationships.
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Affiliation(s)
- Camden D. Gowler
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
| | - Mary A. Rogalski
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
- Biology and Environmental StudiesBowdoin CollegeBrunswickMEUSA
| | - Clara L. Shaw
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
- Department of BiologyThe Pennsylvania State UniversityUniversity ParkPAUSA
| | | | - Meghan A. Duffy
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMIUSA
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Taxonomy and phylogeny of Aphanomycopsis bacillariacearum, a holocarpic oomycete parasitoid of the freshwater diatom genus Pinnularia. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01668-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AbstractInvestigations into simple holocarpic oomycetes are challenging, because of the obligate biotrophic nature of many lineages and the periodic presence in their hosts. Thus, despite recent efforts, still, the majority of species described remains to be investigated for their phylogenetic relationships. One of these species is Aphanomycopsis bacillariacearum, the type species of the genus Aphanomycopsis. Species of Aphanomycopsis are endobiotic holocarpic parasites of diverse hosts (e.g., diatoms, desmids, dinoflagellates). All species classified in this genus were assigned to it based on the presence of branching hyphae and the formation of two generations of zoospores, of which the first one is not motile. Originally, Aphanomycopsis with its type species, A. bacillariacearum, had been classified in the Saprolegniaceae. However, the genus has undergone multiple taxonomic reassignments (to Ectrogellaceae, Lagenidiaceae, and Leptolegniellaceae) in the past. To settle the taxonomy and investigate the phylogenetic placement of Aphanomycopsis, efforts were undertaken to isolate A. bacillariacearum from its original host, Pinnularia viridis and infer its phylogenetic placement based on nrSSU (18S) sequences. By targeted isolation, the diatom parasitoid was rediscovered from Heiðarvatn lake, Höskuldsstaðir, Iceland. Phylogenetic reconstruction shows that A. bacillariacearum from Pinnularia viridis is embedded within the Saprolegniales, and largely unrelated to both diatom-infecting oomycetes in the Leptomitales (Ectrogella, Lagenisma) and those placed within the early-diverging lineages (Miracula, Diatomophthora) of the Oomycota.
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9
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Martin WW, Warren A. Periplasma, gen. nov., a new oomycete lineage with isogamous sexual reproduction. Mycologia 2020; 112:989-1002. [PMID: 32845791 DOI: 10.1080/00275514.2020.1797385] [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] [Indexed: 10/23/2022]
Abstract
This paper describes the taxonomy, developmental morphology, and phylogeny of Periplasma isogametum, a new monotypic member of the Leptomitales (Oomycota). In phylogenetic trees inferred from concatenated and separate nuc 18S rDNA (18S) and nuc 28S rDNA (28S) sequences, P. isogametum forms a well-supported clade related to but distinct from Apodachlya, a member of the Leptomitales. The organism is a holocarpic facultative saprotroph of moribund aquatic insects but grows well on a variety of mycological media in which it produces large eucarpic hyphae with a peripheral layer of protoplasm surrounding a central vacuole. In zoosporogenesis, a peripheral network of zoospore initials collapses to the center of the zoosporangium and is partitioned into individual heterokont zoospores. Sexual reproduction involves morphological isogamy in which male gametes produce elongate fertilization tubes, which fuse with female gametes, which are subsequently converted into thick-walled oospores. Developmental morphology is detailed in photomicrographs and pointillism drawings.
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Affiliation(s)
- W Wallace Martin
- Department of Biology, Randolph-Macon College , Ashland, Virginia 23005
| | - Alyssa Warren
- Department of Biology, Randolph-Macon College , Ashland, Virginia 23005
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10
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Buaya AT, Thines M. Bolbea parasitica gen. et sp. nov., a cultivable holocarpic parasitoid of the early-diverging Saprolegniomycetes. Fungal Syst Evol 2020; 6:129-137. [PMID: 32904153 PMCID: PMC7451777 DOI: 10.3114/fuse.2020.06.07] [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] [Indexed: 11/16/2022] Open
Abstract
Holocarpic oomycetes convert their entire cytoplasm into zoospores and thus do not form dedicated sporangia or hyphal compartments for asexual reproduction. The majority of holocarpic oomycetes are obligate parasites and parasitoids of a diverse suite of organisms, among them green and red algae, brown seaweeds, diatoms, fungi, oomycetes and invertebrates. Most of them are found among the early diverging oomycetes or the Peronosporomycetes, and some in the early-diverging Saprolegniomycetes (Leptomitales). The obligate parasitism renders it difficult to study some of these organisms. Only a few members of the genus Haliphthoross. l. have been cultured without their hosts, and of the parasitoid Leptomitales, some transient cultures have been established, which are difficult to maintain. Here, the cultivation of a new holocarpic oomycete genus of the Leptomitales, Bolbea, is presented. Bolbea is parasitic to ostracods, is readily cultivable on malt extract agar, and upon contact with water converts its cytoplasm into zoospores. Its morphology and phylogenetic relationships are reported. Due to the ease of cultivation and the ready triggering of zoospore development, similar to some lagenidiaceous oomycetes, the species could be a promising model to study sporulation processes in detail.
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Affiliation(s)
- A T Buaya
- Goethe-Universität Frankfurt am Main, Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Max-von-Laue-Str. 13, D-60438 Frankfurt am Main, Germany.,Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany
| | - M Thines
- Goethe-Universität Frankfurt am Main, Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Max-von-Laue-Str. 13, D-60438 Frankfurt am Main, Germany.,Senckenberg Biodiversity and Climate Research Centre, Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany.,LOEWE Centre for Translational Biodiversity Genomics, Georg-Voigt-Str. 14-16, D-60325 Frankfurt am Main, Germany
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11
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Rogalski MA, Duffy MA. Local adaptation of a parasite to solar radiation impacts disease transmission potential, spore yield, and host fecundity. Evolution 2020; 74:1856-1864. [PMID: 32052425 DOI: 10.1111/evo.13940] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 01/10/2020] [Accepted: 01/26/2020] [Indexed: 12/29/2022]
Abstract
Environmentally transmitted parasites spend time in the abiotic environment, where they are subjected to a variety of stressors. Learning how they face this challenge is essential if we are to understand how host-parasite interactions may vary across environmental gradients. We used a zooplankton-bacteria host-parasite system where availability of sunlight (solar radiation) influences disease dynamics to look for evidence of parasite local adaptation to sunlight exposure. We also examined how variation in sunlight tolerance among parasite strains impacted host reproduction. Parasite strains collected from clearer lakes (with greater sunlight penetration) were most tolerant of the negative impacts of sunlight exposure, suggesting local adaptation to sunlight conditions. This adaptation came with both a cost and a benefit for parasites: parasite strains from clearer lakes produced relatively fewer transmission stages (spores) but these strains were more infective. After experimental sunlight exposure, the most sunlight-tolerant parasite strains reduced host fecundity just as much as spores that were never exposed to sunlight. Sunlight availability varies greatly among lakes around the world. Our results suggest that the selective pressure sunlight exposure exerts on parasites may impact both parasite and host fitness, potentially driving variation in disease epidemics and host population dynamics across sunlight availability gradients.
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Affiliation(s)
- Mary Alta Rogalski
- Bowdoin College, Brunswick, Maine, 04011.,University of Michigan, Ann Arbor, Michigan, 48109
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12
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Corsaro D, Walochnik J, Venditti D, Hauröder B, Michel R. Solving an old enigma: Morellospora saccamoebae gen. nov., sp. nov. (Rozellomycota), a Sphaerita-like parasite of free-living amoebae. Parasitol Res 2020; 119:925-934. [PMID: 32048025 DOI: 10.1007/s00436-020-06623-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/05/2020] [Indexed: 12/21/2022]
Abstract
The Rozellomycota form a lineage basal or sister to the Fungi, ancestor of Microsporidia. Their biodiversity is very rich but remains poorly characterized. The few known species are all parasites, whether of water molds and algae (Rozella), crustaceans (Mitosporidium), or as endonuclear parasites of amoebae (Nucleophaga, Paramicrosporidium). Since the nineteenth century, intracytoplasmic parasites of various protozoa have been described as species of the same genus Sphaerita. However, it was later thought possible to separate these parasites into at least two distinct groups, those forming flagellated zoospores, prevalent in Euglena and other flagellates, and those forming immobile spores, found mainly in free-living and endozoic amoebae. Herein, we report the recovery of a strain of the free-living amoeba species Saccamoeba lacustris, naturally infected by an intracytoplasmic parasite, which under light microscope has a morphology consistent with that of Sphaerita. Biomolecular analyses were thus performed. Our results show that the intracytoplasmic parasite of Saccamoeba belongs to the same subgroup of Mitosporidium and that it forms a new genus within Rozellomycota, Morellospora, that corresponds to the former spore-forming Sphaerita-like parasites of amoebae.
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Affiliation(s)
- Daniele Corsaro
- CHLAREAS, 12 rue du Maconnais, F-54500, Vandoeuvre-lès-Nancy, France.
| | - Julia Walochnik
- Molecular Parasitology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Kinderspitalgasse 15, 1095, Vienna, Austria
| | - Danielle Venditti
- CHLAREAS, 12 rue du Maconnais, F-54500, Vandoeuvre-lès-Nancy, France
| | - Bärbel Hauröder
- Department of Pathology, Electron Microscopy Facility, Bundeswehr Central Hospital Koblenz, Andernacher Strasse 100, 56070, Koblenz, Germany
| | - Rolf Michel
- Department of Pathology, Electron Microscopy Facility, Bundeswehr Central Hospital Koblenz, Andernacher Strasse 100, 56070, Koblenz, Germany
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13
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Affiliation(s)
| | | | - Lincoln Mullen
- University of California, Berkeley, CA
- George Mason University, Fairfax, VA
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14
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Toenshoff ER, Fields PD, Bourgeois YX, Ebert D. The End of a 60-year Riddle: Identification and Genomic Characterization of an Iridovirus, the Causative Agent of White Fat Cell Disease in Zooplankton. G3 (BETHESDA, MD.) 2018; 8:1259-1272. [PMID: 29487186 PMCID: PMC5873915 DOI: 10.1534/g3.117.300429] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/08/2018] [Indexed: 12/11/2022]
Abstract
The planktonic freshwater crustacean of the genus Daphnia are a model system for biomedical research and, in particular, invertebrate-parasite interactions. Up until now, no virus has been characterized for this system. Here we report the discovery of an iridovirus as the causative agent of White Fat Cell Disease (WFCD) in Daphnia WFCD is a highly virulent disease of Daphnia that can easily be cultured under laboratory conditions. Although it has been studied from sites across Eurasia for more than 60 years, its causative agent had not been described, nor had an iridovirus been connected to WFCD before now. Here we find that an iridovirus-the Daphnia iridescent virus 1 (DIV-1)-is the causative agent of WFCD. DIV-1 has a genome sequence of about 288 kbp, with 39% G+C content and encodes 367 predicted open reading frames. DIV-1 clusters together with other invertebrate iridoviruses but has by far the largest genome among all sequenced iridoviruses. Comparative genomics reveal that DIV-1 has apparently recently lost a substantial number of unique genes but has also gained genes by horizontal gene transfer from its crustacean host. DIV-1 represents the first invertebrate iridovirus that encodes proteins to purportedly cap RNA, and it contains unique genes for a DnaJ-like protein, a membrane glycoprotein and protein of the immunoglobulin superfamily, which may mediate host-pathogen interactions and pathogenicity. Our findings end a 60-year search for the causative agent of WFCD and add to our knowledge of iridovirus genomics and invertebrate-virus interactions.
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Affiliation(s)
- Elena R Toenshoff
- Basel University, Department of Environmental Sciences, Zoology, Vesalgasse 1, CH-4051 Basel, Switzerland
| | - Peter D Fields
- Basel University, Department of Environmental Sciences, Zoology, Vesalgasse 1, CH-4051 Basel, Switzerland
| | - Yann X Bourgeois
- Basel University, Department of Environmental Sciences, Zoology, Vesalgasse 1, CH-4051 Basel, Switzerland
| | - Dieter Ebert
- Basel University, Department of Environmental Sciences, Zoology, Vesalgasse 1, CH-4051 Basel, Switzerland
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15
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High-throughput sequencing reveals diverse oomycete communities in oligotrophic peat bog micro-habitat. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2016.05.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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