DOCSLIB.ORG

The Expression of Virulence for a Mixed-Mode Transmitted Parasite in a Diapausing Host

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Expression of Virulence for a Mixed-Mode Transmitted Parasite in a Diapausing Host 1097 The expression of virulence for a mixed-mode transmitted parasite in a diapausing host ELHAM SHEIKH-JABBARI1*, MATTHEW D. HALL1†, FRIDA BEN-AMI2 and DIETER EBERT1,3 1 University of Basel, Zoological Institute, Vesalgasse 1, 4051 Basel, Switzerland 2 Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel 3 Tvärminne Zoological Station, FI-10900 Hanko, Finland (Received 11 November 2013; revised 26 January and 27 February 2014; accepted 3 March 2014; first published online 30 April 2014) SUMMARY Many parasites survive harsh periods together with their hosts. Without the possibility of horizontal transmission during host diapause, parasite persistence depends entirely on host survival. We therefore hypothesize that a parasite should be avirulent during its host’s diapausing stage. In contrast, the parasite may express higher virulence, i.e. parasite-induced fitness reduction of the host, during host life stages with good opportunities for horizontal transmission. Here we study the effects of a vertically and horizontally transmitted microsporidium parasite, Hamiltosporidium tvaerminnensis, on the quantity and survival of resting eggs of its host Daphnia magna. We find that the parasite did not affect egg volume, hatching success and time to hatching of the Daphnia’s resting eggs, although it did strongly reduce the number of resting eggs produced by infected females, revealing high virulence during the non-diapause phase of the host’s life cycle. These results also explain another aspect of this system – namely the strong decline in natural population prevalence across diapause. This decline is not caused by mortality in infected resting stages, as was previously hypothesized, but because infected female hosts produce lower rates of resting eggs. Together, these results help explain the epidemiological dynamics of a microsporidian disease and highlight the adaptive nature of life stage-dependent parasite virulence. Key words: Daphnia magna, Hamiltosporidium tvaerminnensis, diapause, host-parasite, infection, rock pools. INTRODUCTION strongly fluctuating densities, including host dia- pause (Regniere, 1984; Lipsitch et al. 1995; Sorrell In seasonal habitats, many species undergo periods of et al. 2009; Ebert, 2013). reduced activity, or diapause, to survive adverse Little is known about the expression of parasite environmental conditions. For parasites, host dia- virulence during host diapause. Under non-diapause pause may constitute a bottleneck, as survival outside conditions, virulence is thought to evolve as a balance the host may be impossible and strongly impair between the costs of harming the host (and parasite) opportunities for transmission during metabolically and the benefits of within-host competition and inactive host stages such as resting eggs and seeds transmission-stage production (Bull, 1994; Alizon (Thomson, 1958). One strategy that parasites use to et al. 2009). Based on this trade-off model, most endure such periods is to undergo diapause together parasites are expected to evolve intermediate levels of with their host (Thomson, 1958; Regniere, 1984; harm to the host (=virulence). During host diapause, Bauer and Nordin, 1989b; Evseeva, 1996;Brown however, when parasites have reduced, or zero, et al. 2003; Andreadis, 2005). This is often achieved opportunities for transmission from the resting host when the parasite is vertically transmitted (trans- they must maximize their chances of surviving mission between mothers and offspring) into dia- together with the host. Thus it is expected that the pausing eggs, seeds or embryos, even though these parasite should be avirulent to ensure its and the parasites may otherwise be horizontally transmitted host’s survival. This is similar to when a mixed-mode (between hosts not related in direct line) (Regniere, transmitting parasite loses its opportunities for 1984; Mink, 1993). Generally, the ability to transmit horizontal transmission and therefore is expected to both vertically and horizontally (=mixed mode evolve avirulence (Fine, 1975; Stewart and Levin, transmission) is an efficient strategy for parasites, 1984; Bull et al. 1991; Magalon et al. 2010). Here allowing them to persist in host populations with we suggest that parasites would do best to adopt strategies specific to each host life stage: to express * Corresponding author: University of Basel, Zoological high levels of virulence during the metabolically Institute, Vesalgasse 1, 4051 Basel, Switzerland. E-mail: ’ [email protected] active phase of the host s life cycle, and to be avirulent † Current address: School of Biological Sciences, Monash during the host’s diapause, when horizontal trans- University, Melbourne, Victoria 3800, Australia. mission is not possible. Parasitology (2014), 141, 1097–1107. © Cambridge University Press 2014 doi:10.1017/S0031182014000456 Elham Sheikh-Jabbari and others 1098 Mixed-mode transmission is common among inside a protective shell called an ephippium. microsporidia and is often found in parasites with Ephippia allow hosts and parasites to survive harsh diapausing hosts. These parasites are typically periods of freezing or drought (Altermatt and Ebert, virulent, reducing host survival and fecundity 2010). Resting stages hatch after environmental (Agnew and Koella, 1999; Dunn and Smith, 2001; stimuli indicate better conditions. During the active Futerman et al. 2006; Rutrecht and Brown, 2008). part of their life cycle, Daphnia inhabit the plankton Furthermore, when transmitted from mothers to of freshwater ponds and lakes. their directly developing offspring, these parasites The microsporidium H. tvaerminnensis (Haag et al. often dramatically reduce egg hatching and embryo 2011) (formerly called Octosporea bayeri)isan survival (Andreadis and Hall, 1979; Andreadis, 1983; obligate parasite of D. magna. It is horizontally Bauer and Nordin, 1989a; Becnel et al. 1995; Raina transmitted through environmental spores and ver- et al. 1995). Whether the same is true for parasites tically transmitted to both asexually and sexually that are vertically transmitted to resting eggs and produced host eggs (Vizoso et al. 2005; Ebert et al. embryos is not known. Vertical transmission to 2007). Hamiltosporidium tvaerminnensis greatly re- resting eggs and embryos is important in seasonal duces the competitive ability of its hosts in the environments, where many microsporidia are pre- planktonic phase (Lass and Ebert, 2006; Bieger and dominantly transmitted horizontally during the Ebert, 2009). In vertically infected hosts, virulent host’s growth season, but are vertically transmitted effects are particularly strong, reducing lifetime in the diapausing stage of the host (Thomson, 1958; reproductive success by up to 85% (Ben-Ami et al. Bauer and Nordin, 1989b; Raina et al. 1995; Vizoso 2011). Upon infection, Hamiltosporidium produces and Ebert, 2004; Ebert, 2013). Although these several million spores in the host’s body. These microsporidia are described as highly virulent during spores are released for horizontal transmission after the host’s growth season (including killing the the host’s death. Spore production is a proxy for developing eggs; references as before), nothing has the parasite’s horizontal transmission potential and been reported about virulence during the host’s is traded-off with reduction in host fecundity, resting phase. a measure for virulence (Vizoso and Ebert, 2005). Here we test the hypothesis that a parasite that is Infected resting eggs do not contain fully developed, virulent during the host’s growth phase expresses low microsporidian spores, making transmission from levels of virulence during host diapause, thus max- resting eggs impossible (E. Sheikh-Jabbari, unpub- imizing its likelihood of surviving diapause together lished). with its host. We test this hypothesis using the Infections by H. tvaerminnensis are recognized by microsporidium Hamiltosporidium tvaerminnensis the presence of the typical spores. To observe the (Haag et al. 2011) of the water flea Daphnia magna, spores, which are very numerous when present, which lives in a seasonal habitat. Three complemen- whole D. magna are placed on glass slides with a tary experiments were conducted, each focusing on a drop of medium and a cover-slip is pressed upon different aspect of infectious disease. In the first the Daphnia with a rotating motion so as to spread experiment resting eggs were collected from natural the tissues evenly. These wet-mount preparations rock pools. All populations were infected but the are observed using phase-contrast microscopy at prevalence was unknown. In the second experiment 400× magnification. Spore types of H. tvaerminnensis infected and uninfected females collected from one have been described and can be easily identified and natural rock pool were used to produce monoclonal differentiated from other parasites, even from the populations placed in mesocosms in the field. In the congeneric Hamiltosporidium magnivora, also a para- third experiment infected and uninfected host site of D. magna (Vizoso et al. 2005; Haag et al. 2011). clones were reared in the laboratory. By quantifying No other vertically transmitted microsporidia are the parasite’sinfluence on resting stage production, known to infect D. magna in this metapopulation egg morphology and hatching, we test whether this (Ebert et al. 2001). Molecular analysis confirmed that otherwise virulent parasite expresses reduced viru- H. tvaerminnensis from these rock pool populations
Load more

Recommended publications
  • Filling Gaps in the Microsporidian Tree: Rdna Phylogeny of Chytridiopsis Typographi (Microsporidia: Chytridiopsida)
    Parasitology Research (2019) 118:169–180 https://doi.org/10.1007/s00436-018-6130-1 GENETICS, EVOLUTION, AND PHYLOGENY - ORIGINAL PAPER Filling gaps in the microsporidian tree: rDNA phylogeny of Chytridiopsis typographi (Microsporidia: Chytridiopsida) Daniele Corsaro1 & Claudia Wylezich2 & Danielle Venditti1 & Rolf Michel3 & Julia Walochnik4 & Rudolf Wegensteiner5 Received: 7 August 2018 /Accepted: 23 October 2018 /Published online: 12 November 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Microsporidia are intracellular eukaryotic parasites of animals, characterized by unusual morphological and genetic features. They can be divided in three main groups, the classical microsporidians presenting all the features of the phylum and two putative primitive groups, the chytridiopsids and metchnikovellids. Microsporidia originated from microsporidia-like organisms belong- ing to a lineage of chytrid-like endoparasites basal or sister to the Fungi. Genetic and genomic data are available for all members, except chytridiopsids. Herein, we filled this gap by obtaining the rDNA sequence (SSU-ITS-partial LSU) of Chytridiopsis typographi (Chytridiopsida), a parasite of bark beetles. Our rDNA molecular phylogenies indicate that Chytridiopsis branches earlier than metchnikovellids, commonly thought ancestral, forming the more basal lineage of the Microsporidia. Furthermore, our structural analyses showed that only classical microsporidians present 16S-like SSU rRNA and 5.8S/LSU rRNA gene fusion, whereas the standard eukaryote rRNA gene structure, although slightly reduced, is still preserved in the primitive microsporidians, including 18S-like SSU rRNA with conserved core helices, and ITS2-like separating 5.8S from LSU. Overall, our results are consistent with the scenario of an evolution from microsporidia-like rozellids to microsporidians, however suggesting for metchnikovellids a derived position, probably related to marine transition and adaptation to hyperparasitism.
    [Show full text]
  • Secreted Proteins in Microsporidian Parasites: a Functional and Evolutionary Perspective on Host-Parasite Interactions
    Secreted proteins in microsporidian parasites: a functional and evolutionary perspective on host-parasite interactions. Submitted by Scott Edward Campbell to the University of Exeter as a thesis for the degree of Doctor of Philosophy in Biological Science. In September 2013 This thesis is available for Library use on the understanding that it is copyright material and that no quotation from this thesis may be published without proper acknowledgment. I certify that all material in this thesis which is not my own work has been identified and that no material has previously been submitted and approved for the award of a degree by this or any other University. Signature ……………………………………. Page| 1 Abstract The Microsporidia form a phylum of obligate intracellular parasites known to cause disease in humans and a diverse range of economically important animal species. Once classified as ‘primitive’ eukaryotes, it is now recognised that the peculiarities of microsporidian genomics and cell biology are, in fact, the consequence of extreme reduction allowed by an intimate relationship with the host cell. Excluding survival as an extracellular spore, microsporidia are in direct contact with the host throughout their developmental lifecycle, from entry to egress. Host cell manipulations have been described in morphological terms, but despite this, characterisation of such processes at the molecular level remains challenging. The logistics of the microsporidian lifecycle suggest secreted proteins and membrane proteins with extracellular domains may be involved in virulence and implicated in host cell manipulation. This study employs bioinformatic tools to predict secreted proteins in diverse microsporidia and comparative genomics to identify conserved proteins which may be required for host cell manipulation, pathogenicity and lifecycle progression.
    [Show full text]
  • Baltic Sea Genetic Biodiversity: Current Knowledge Relating to Conservation Management
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Brage IMR Received: 21 August 2016 Revised: 26 January 2017 Accepted: 16 February 2017 DOI: 10.1002/aqc.2771 REVIEW ARTICLE Baltic Sea genetic biodiversity: Current knowledge relating to conservation management Lovisa Wennerström1* | Eeva Jansson1,2* | Linda Laikre1 1 Department of Zoology, Stockholm University, SE‐106 91 Stockholm, Sweden Abstract 2 Institute of Marine Research, Bergen, 1. The Baltic Sea has a rare type of brackish water environment which harbours unique genetic Norway lineages of many species. The area is highly influenced by anthropogenic activities and is affected Correspondence by eutrophication, climate change, habitat modifications, fishing and stocking. Effective genetic Lovisa Wennerström, Department of Zoology, management of species in the Baltic Sea is highly warranted in order to maximize their potential SE‐106 91 Stockholm, Sweden. for survival, but shortcomings in this respect have been documented. Lack of knowledge is one Email: [email protected] reason managers give for why they do not regard genetic diversity in management. Funding information Swedish Research Council Formas (LL); The 2. Here, the current knowledge of population genetic patterns of species in the Baltic Sea is BONUS BAMBI Project supported by BONUS reviewed and summarized with special focus on how the information can be used in (Art 185), funded jointly by the European management. The extent to which marine protected areas (MPAs) protect genetic diversity Union and the Swedish Research Council Formas (LL); Swedish Cultural Foundation in is also investigated in a case study of four key species.
    [Show full text]
  • Four QTL Underlie Resistance to a Microsporidian Parasite That May Drive Genome Evolution in Its 2 Daphnia Host
    bioRxiv preprint doi: https://doi.org/10.1101/847194; this version posted November 20, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. 1 Four QTL underlie resistance to a microsporidian parasite that may drive genome evolution in its 2 Daphnia host 3 Devon Keller1, Devin Kirk1,2, Pepijn Luijckx1,3 4 1 Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, 5 M5S 3G5. 6 2 Current address: Department of Biology, Stanford University, Stanford, USA. 7 3 School of Natural Sciences, Zoology, Trinity College Dublin, Dublin 2, Ireland 8 Author contributions 9 DK, DK and PL designed the study and conducted experiments. PL conducted the analysis. PL wrote the 10 first draft of the manuscript, and all authors significantly contributed to revisions. 11 Abstract: 12 Despite its pivotal role in evolutionary and ecological processes the genetic architecture underlying host- 13 parasite interactions remains understudied. Here we use a quantitative trait loci approach to identify 14 regions in the Daphnia magna genome that provide resistance against its microsporidium parasite 15 Ordospora colligata. The probability that Daphnia became infected was affected by a single locus and an 16 interaction between two additional loci. A fourth locus influenced the number of spores that grew within 17 the host. Comparing our findings to previously published genetic work on Daphnia magna revealed that 18 two of these loci may be the same as detected for another microsporidium parasite, suggesting a general 19 immune response to this group of pathogens.
    [Show full text]
  • Origin and Evolution of Fungal HECT Ubiquitin Ligases Ignacio Marín
    www.nature.com/scientificreports OPEN Origin and evolution of fungal HECT ubiquitin ligases Ignacio Marín Ubiquitin ligases (E3s) are basic components of the eukaryotic ubiquitination system. In this work, the Received: 29 December 2017 emergence and diversifcation of fungal HECT ubiquitin ligases is described. Phylogenetic and structural Accepted: 11 April 2018 data indicate that six HECT subfamilies (RSP5, TOM1, UFD4, HUL4, HUL4A and HUL5) existed in Published: xx xx xxxx the common ancestor of all fungi. These six subfamilies have evolved very conservatively, with only occasional losses and duplications in particular fungal lineages. However, an early, drastic reduction in the number of HECT genes occurred in microsporidians, in parallel to the reduction of their genomes. A signifcant correlation between the total number of genes and the number of HECT-encoding genes present in fungi has been observed. However, transitions from unicellularity to multicellularity or vice versa apparently had no efect on the evolution of this family. Likely orthologs or co-orthologs of all fungal HECT genes have been detected in animals. Four genes are deduced to be present in the common ancestor of fungi, animals and plants. Protein-protein interactions detected in both the yeast Saccharomyces cerevisiae and humans suggest that some ancient functions of HECT proteins have been conserved since the animals/fungi split. Protein ubiquitination is involved in the control of multiple essential functions in all eukaryotic species1–3. Given its importance, there is a signifcant interest in understanding the evolution of the ubiquitination system, from its early origin4–6 to its complex patterns of diversifcation in eukaryotic phyla, in which the ubiquitination machinery typically involves hundreds of proteins7.
    [Show full text]
  • S41437-020-0332-X.Pdf
    Heredity (2020) 125:173–183 https://doi.org/10.1038/s41437-020-0332-x ARTICLE An alternative route of bacterial infection associated with a novel resistance locus in the Daphnia–Pasteuria host–parasite system 1 1 1,2 1 Gilberto Bento ● Peter D. Fields ● David Duneau ● Dieter Ebert Received: 12 September 2019 / Revised: 7 June 2020 / Accepted: 7 June 2020 / Published online: 19 June 2020 © The Author(s) 2020. This article is published with open access Abstract To understand the mechanisms of antagonistic coevolution, it is crucial to identify the genetics of parasite resistance. In the Daphnia magna–Pasteuria ramosa host–parasite system, the most important step of the infection process is the one in which P. ramosa spores attach to the host’s foregut. A matching-allele model (MAM) describes the host–parasite genetic interactions underlying attachment success. Here we describe a new P. ramosa genotype, P15, which, unlike previously studied genotypes, attaches to the host’s hindgut, not to its foregut. Host resistance to P15 attachment shows great diversity across natural populations. In contrast to P. ramosa genotypes that use foregut attachment, P15 shows some quantitative variation in attachment success and does not always lead to successful infections, suggesting that hindgut attachment fi 1234567890();,: 1234567890();,: represents a less-ef cient infection mechanism than foregut attachment. Using a Quantitative Trait Locus (QTL) approach, we detect two significant QTLs in the host genome: one that co-localizes with the previously described D. magna PR locus of resistance to foregut attachment, and a second, major QTL located in an unlinked genomic region.
    [Show full text]
  • Transposable Element Abundance Correlates with Mode Of
    Albuquerque et al. Mobile DNA (2020) 11:19 https://doi.org/10.1186/s13100-020-00218-8 SHORT REPORT Open Access Transposable element abundance correlates with mode of transmission in microsporidian parasites Nathalia Rammé Medeiros de Albuquerque1, Dieter Ebert2 and Karen Luisa Haag1* Abstract The extreme genome reduction and physiological simplicity of some microsporidia has been attributed to their intracellular, obligate parasitic lifestyle. Although not all microsporidian genomes are small (size range from about 2 to 50 MB), it is suggested that the size of their genomes has been streamlined by natural selection. We explore the hypothesis that vertical transmission in microsporidia produces population bottlenecks, and thus reduces the effectiveness of natural selection. Here we compare the transposable element (TE) content of 47 microsporidian genomes, and show that genome size is positively correlated with the amount of TEs, and that species that experience vertical transmission have larger genomes with higher proportion of TEs. Our findings are consistent with earlier studies inferring that nonadaptive processes play an important role in microsporidian evolution. Background gene-sparse genomes is populated by repetitive se- Microsporidia, a phylum of fast evolving intracellular quences, most of which have been identified as transpos- parasites related to fungi [1–3], are interesting models able elements [11]. It is suggested that the majority of for studying the mechanisms shaping eukaryotic genome transposable element (TE) insertions cause mildly dele- evolution. Their genomes are small and highly diverse. terious effects in eukaryotes [12, 13]. Therefore, their Two contrasting genome architectures are found in spread and accumulation depend on the cellular mecha- microsporidians.
    [Show full text]
  • Exploiting the Architecture and the Features of the Microsporidian Genomes to Investigate Diversity and Impact of These Parasites on Ecosystems
    Heredity (2015) 114, 441–449 & 2015 Macmillan Publishers Limited All rights reserved 0018-067X/15 www.nature.com/hdy REVIEW Exploiting the architecture and the features of the microsporidian genomes to investigate diversity and impact of these parasites on ecosystems E Peyretaillade1, D Boucher1, N Parisot1,2, C Gasc1, R Butler3, J-F Pombert3, E Lerat4 and P Peyret1 Fungal species play extremely important roles in ecosystems. Clustered at the base of the fungal kingdom are Microsporidia, a group of obligate intracellular eukaryotes infecting multiple animal lineages. Because of their large host spectrum and their implications in host population regulation, they influence food webs, and accordingly, ecosystem structure and function. Unfortunately, their ecological role is not well understood. Present also as highly resistant spores in the environment, their characterisation requires special attention. Different techniques based on direct isolation and/or molecular approaches can be considered to elucidate their role in the ecosystems, but integrating environmental and genomic data (for example, genome architecture, core genome, transcriptional and translational signals) is crucial to better understand the diversity and adaptive capacities of Microsporidia. Here, we review the current status of Microsporidia in trophic networks; the various genomics tools that could be used to ensure identification and evaluate diversity and abundance of these organisms; and how these tools could be used to explore the microsporidian life cycle in different
    [Show full text]
  • LIVRO DE RESUMOS Dorn, Marcio EGB 2017 - Livro De Resumos / Marcio Dorn, Rodrigo Ligabue Braun, Hugo Verli
    AULAS PALESTRAS MINI-CURSOS SESSÃO DE PÔSTERES LIVRO DE RESUMOS Dorn, Marcio EGB 2017 - Livro de Resumos / Marcio Dorn, Rodrigo Ligabue Braun, Hugo Verli. -- Porto Alegre, 2017. 39 f. Anais/Livro de Resumos - Universidade Federal do Rio Grande do Sul, Instituto de Informática e Centro de Biotecnologia - UFRGS, 2017. 1. bioinformática. 2. biologia computacional. 3. escola. I. Ligabue Braun, Rodrigo. II. Verli, Hugo. I. , . II. Título. DOI: 10.13140/RG.2.2.34681.77929 DETECTION OF LTR RETROTRANSPOSONS IN THREE Hamiltosporidium lineages ALBUQUERQUE, NATHALIA RAMMÉ MEDEIROS1; SILVEIRA, JULIANO DE OLIVEIRA1; HAAG, KAREN LUISA1. 1Laboratório de Genômica Evolutiva, Departamento de Genética, Universidade Federal do Rio Grande do Sul. Microsporidia have one of the smallest genomes among eukaryotes, due to their obligate intracellular parasitism that resulted in an extensive reduction in genome size and complexity. Transposable elements (TEs) compose a high fraction in eukaryotic genomes, the vast majority being retrotransposons, due to their "copy-paste" transposition mechanism. TEs are able to mutate genes, alter gene regulation and generate new genes. Transposition events can be deleterious when TEs integrate in active coding regions and disrupt important genes. Due to the absence of recombination, TEs may accumulate in asexual genomes and contribute to extinction of asexual organisms. However, there is no evidence showing different TE densities between sexual and asexual lineages. We assessed the genomes of three Hamiltosporidium lineages for TE content. Two genomes of H. magnivora lineages (BEOM2 and ILBN2) that reproduce sexually and are vertically transmitted, and one genome of an H. tvaerminnensis lineage (FIOER33) that reproduces asexually and is both vertically and horizontally transmitted.
    [Show full text]
  • Vertical Transmission and Early Diagnosis of the Microsporidian Enterocytozoon Hepatonaei in Whiteleg Shrimp Penaeus Vannamei
    JOURNAL OF PURE AND APPLIED MICROBIOLOGY, Sept. 2018. Vol. 12(3), p. proof Vertical Transmission and Early Diagnosis of the Microsporidian Enterocytozoon hepatonaei in Whiteleg Shrimp Penaeus vannamei Hung Vu-Khac1, Thuy Nguyen Thi Thanh2, Giang Nguyen Thi Thu1, Chi Hieu Le3, Van Duy Nguyen3,4* 1Institute of Veterinary Research and Development of Central Vietnam, Nha Trang, Vietnam. 2 Research Institute for Aquaculture No. 3, Nha Trang, Vietnam. 3 Faculty of Engineering and Science, University of Greenwich, Chatham, Kent, UK. 4Institute of Biotechnology and Environment, Nha Trang University, Nha Trang, Vietnam. doi: (Received: 10 June 2018; accepted: 20 July 2018) Microsporidia, which are ubiquitous obligate intracellular parasites responsible for a variety of diseases and economic losses in farming, have different transmission strategies. While horizontal transmission relies on sufûcient parasite numbers released into environment, vertical transmission requires host reproduction to occur leading to a lower virulence, and also induces a sex ratio distortion. The second strategy has been reported in a broad range of hosts from protists to mammals, in which insects and amphipod crustaceans as the most common. The present study shows the first evidence of vertical transmission of a microsporidia in decapod crustaceans via an experimental description of the infection by Enterocytozoon hepatopenaei (EHP) in whiteleg shrimp Penaeus vannamei. The group of healthy shrimp was infected with EHP by feeding with infected-shrimp tissue and sharing habitat. The presence of EHP in the infected shrimps was detected by using Polymerase Chain Reaction (PCR) method with specific primers EHP-510F/EHP-510R and histopathological analysis. The Nauplius, Zoae 1 and Zoae 2 stages collected from the infected female broodstocks demonstrated that EHP can infect offspring from their parental shrimp, and interestingly EHP can be detected from Nauplius stage of shrimp by the use of PCR method.
    [Show full text]
  • Dear Author, Here Are the Proofs of Your Article. • You Can Submit Your
    Dear Author, Here are the proofs of your article. • You can submit your corrections online, via e-mail or by fax. • For online submission please insert your corrections in the online correction form. Always indicate the line number to which the correction refers. • You can also insert your corrections in the proof PDF and email the annotated PDF. • For fax submission, please ensure that your corrections are clearly legible. Use a fine black pen and write the correction in the margin, not too close to the edge of the page. • Remember to note the journal title, article number, and your name when sending your response via e-mail or fax. • Check the metadata sheet to make sure that the header information, especially author names and the corresponding affiliations are correctly shown. • Check the questions that may have arisen during copy editing and insert your answers/ corrections. • Check that the text is complete and that all figures, tables and their legends are included. Also check the accuracy of special characters, equations, and electronic supplementary material if applicable. If necessary refer to the Edited manuscript. • The publication of inaccurate data such as dosages and units can have serious consequences. Please take particular care that all such details are correct. • Please do not make changes that involve only matters of style. We have generally introduced forms that follow the journal’s style. Substantial changes in content, e.g., new results, corrected values, title and authorship are not allowed without the approval of the responsible editor. In such a case, please contact the Editorial Office and return his/her consent together with the proof.
    [Show full text]
  • Supplementary Materials Journal of Fungi New Method for Identifying Fungal Kingdom Enzyme Hotspots from Genome Sequences Lene L
    Supplementary Materials Journal of Fungi New Method for identifying Fungal Kingdom Enzyme Hotspots from Genome Sequences Lene Lange1, Kristian Barrett2, and Anne S. Meyer2 1 BioEconomy, Research & Advisory, Copenhagen, 2500 Valby, Denmark; [email protected] (L.L) 2 Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Building 221, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark; [email protected] (KB), [email protected] (ASM) Table S1. List of the rank of all 1.932 fungal species/strains with regard to biomass degrading capacity based on bioinformatics analysis of their genome sequence. The species are ranked with regard to the Total number of “Function;Family” observations, yet specifying the total number of “Function;Family” observations in each substrate category. The data shown is the full list of data supporting Table 1 in the main manuscript. ACC Submitter Total Xylan Xylan Lignin Pectin Cellulose No Species Class Phylum 1 Pecoramyces ruminatium Neocallimastigo Chytridio 248 85 208 0 541 GCA_000412615.1 Oklahoma State University 2 Neocallimastix californiae Neocallimastigo Chytridio 232 122 172 0 526 GCA_002104975.1 DOE Joint Genome Institute 3 Mycena citricolor Agarico Basidio 91 204 50 149 494 GCA_003987915.1 Universidade de Sao Paulo 4 Verticillium longisporum Sordario Asco 139 176 74 95 484 GCA_001268165.1 SLU 5 Coniochaeta sp. 2T2.1 Sordario Asco 117 102 108 98 425 GCA_009194965.1 DOE Joint Genome Institute 6 Paramyrothecium roridum Sordario Asco 106 163 63 79 411 GCA_003012165.1 USDA, ARS, NCAUR 7 Cadophora sp. DSE1049 Leotio Asco 105 138 75 91 409 GCA_003073865.1 DOE Joint Genome Institute 8 Diaporthe ampelina Sordario Asco 116 129 58 97 400 GCA_001630405.1 Bangalore University 9 Diaporthe longicolla Sordario Asco 111 128 56 90 385 GCA_000800745.1 Purdue University 10 Diaporthe sp.
    [Show full text]