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Kuhl H, Strassert JFH, Čertnerová D, Varga E, Kreuz E, Lamatsch DK, Wuertz S, Köhler J, Monaghan MT, Stöck M. The haplotype-resolved Prymnesium parvum (type B) microalga genome reveals the genetic basis of its fish-killing toxins. Curr Biol 2024:S0960-9822(24)00817-0. [PMID: 38986615 DOI: 10.1016/j.cub.2024.06.033] [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: 03/29/2024] [Revised: 05/13/2024] [Accepted: 06/11/2024] [Indexed: 07/12/2024]
Abstract
The catastrophic loss of aquatic life in the Central European Oder River in 2022, caused by a toxic bloom of the haptophyte microalga Prymnesium parvum (in a wide sense, s.l.), underscores the need to improve our understanding of the genomic basis of the toxin. Previous morphological, phylogenetic, and genomic studies have revealed cryptic diversity within P. parvum s.l. and uncovered three clade-specific (types A, B, and C) prymnesin toxins. Here, we used state-of-the-art long-read sequencing and assembled the first haplotype-resolved diploid genome of a P. parvum type B from the strain responsible for the Oder disaster. Comparative analyses with type A genomes uncovered a genome-size expansion driven by repetitive elements in type B. We also found conserved synteny but divergent evolution in several polyketide synthase (PKS) genes, which are known to underlie toxin production in combination with environmental cues. We identified an approximately 20-kbp deletion in the largest PKS gene of type B that we link to differences in the chemical structure of types A and B prymnesins. Flow cytometry and electron microscopy analyses confirmed diploidy in the Oder River strain and revealed differences to closely related strains in both ploidy and morphology. Our results provide unprecedented resolution of strain diversity in P. parvum s.l. and a better understanding of the genomic basis of toxin variability in haptophytes. The reference-quality genome will enable us to better understand changes in microbial diversity in the face of increasing environmental pressures and provides a basis for strain-level monitoring of invasive Prymnesium in the future.
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Affiliation(s)
- Heiner Kuhl
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Jürgen F H Strassert
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Dora Čertnerová
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic; Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria
| | - Elisabeth Varga
- Department of Food Chemistry and Toxicology, University of Vienna, Vienna, Austria; Unit Food Hygiene and Technology, Centre for Food Science and Veterinary Public Health, Clinical Department for Farm Animals and Food System Science, University of Veterinary Medicine, Vienna, Austria
| | - Eva Kreuz
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Dunja K Lamatsch
- Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria
| | - Sven Wuertz
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Jan Köhler
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Michael T Monaghan
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany; Institut für Biologie, Freie Universität Berlin, Berlin, Germany.
| | - Matthias Stöck
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany.
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2
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Rao D, Füssy Z, Brisbin MM, McIlvin MR, Moran DM, Allen AE, Follows MJ, Saito MA. Flexible B 12 ecophysiology of Phaeocystis antarctica due to a fusion B 12-independent methionine synthase with widespread homologues. Proc Natl Acad Sci U S A 2024; 121:e2204075121. [PMID: 38306482 PMCID: PMC10861871 DOI: 10.1073/pnas.2204075121] [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: 03/19/2022] [Accepted: 11/13/2023] [Indexed: 02/04/2024] Open
Abstract
Coastal Antarctic marine ecosystems are significant in carbon cycling because of their intense seasonal phytoplankton blooms. Southern Ocean algae are primarily limited by light and iron (Fe) and can be co-limited by cobalamin (vitamin B12). Micronutrient limitation controls productivity and shapes the composition of blooms which are typically dominated by either diatoms or the haptophyte Phaeocystis antarctica. However, the vitamin requirements and ecophysiology of the keystone species P. antarctica remain poorly characterized. Using cultures, physiological analysis, and comparative omics, we examined the response of P. antarctica to a matrix of Fe-B12 conditions. We show that P. antarctica is not auxotrophic for B12, as previously suggested, and identify mechanisms underlying its B12 response in cultures of predominantly solitary and colonial cells. A combination of proteomics and proteogenomics reveals a B12-independent methionine synthase fusion protein (MetE-fusion) that is expressed under vitamin limitation and interreplaced with the B12-dependent isoform under replete conditions. Database searches return homologues of the MetE-fusion protein in multiple Phaeocystis species and in a wide range of marine microbes, including other photosynthetic eukaryotes with polymorphic life cycles as well as bacterioplankton. Furthermore, we find MetE-fusion homologues expressed in metaproteomic and metatranscriptomic field samples in polar and more geographically widespread regions. As climate change impacts micronutrient availability in the coastal Southern Ocean, our finding that P. antarctica has a flexible B12 metabolism has implications for its relative fitness compared to B12-auxotrophic diatoms and for the detection of B12-stress in a more diverse set of marine microbes.
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Affiliation(s)
- Deepa Rao
- Earth Atmospheric Planetary Sciences Department, Massachusetts Institute of Technology, Cambridge, MA02139
- Marine Chemistry and Geochemistry Department, Woods Hole, MA02543
| | - Zoltán Füssy
- Microbial and Environmental Genomics Department, J.C. Venter Institute, La Jolla, CA92037
| | | | | | - Dawn M. Moran
- Marine Chemistry and Geochemistry Department, Woods Hole, MA02543
| | - Andrew E. Allen
- Microbial and Environmental Genomics Department, J.C. Venter Institute, La Jolla, CA92037
- Integrative Oceanography Division, Scripps Instition of Oceanography, University of California San Diego, La Jolla, CA92037
| | - Michael J. Follows
- Earth Atmospheric Planetary Sciences Department, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Mak A. Saito
- Marine Chemistry and Geochemistry Department, Woods Hole, MA02543
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3
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Jian J, Wu Z, Silva-Núñez A, Li X, Zheng X, Luo B, Liu Y, Fang X, Workman CT, Larsen TO, Hansen PJ, Sonnenschein EC. Long-read genome sequencing provides novel insights into the harmful algal bloom species Prymnesium parvum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168042. [PMID: 37898203 DOI: 10.1016/j.scitotenv.2023.168042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/20/2023] [Accepted: 10/20/2023] [Indexed: 10/30/2023]
Abstract
Prymnesium parvum is a toxin-producing haptophyte that causes harmful algal blooms worldwide, which are often associated with massive fish-kills and subsequent economic losses. In here, we present nuclear and plastid genome assemblies using PacBio HiFi long reads and DNBseq short reads for the two P. parvum strains UTEX 2797 and CCMP 3037, representing producers of type A prymnesins. Our results show that the P. parvum strains have a moderate haptophyte genome size of 97.56 and 107.32 Mb. The genome assemblies present one of highest contiguous assembled contig sequences to date consisting of 463 and 362 contigs with a contig N50 of 596.99 kb and 968.39 kb for strain UTEX 2797 and CCMP 3037, respectively. The assembled contigs of UTEX 2797 and CCMP 3037 were anchored to 34 scaffolds, with a scaffold N50 of 5.35 Mb and 3.61 Mb, respectively, accounting for 93.2 % and 97.9 % of the total length. Each plastid genome comprises a circular contig. A total of 20,578 and 19,426 protein-coding genes were annotated for UTEX 2797 and CCMP 3037. The expanded gene family analysis showed that starch and sucrose metabolism, sulfur metabolism, energy metabolism and ABC transporters are involved in the evolution of P. parvum. Polyketide synthase (PKS) genes responsible for the production of secondary metabolites such as prymnesins displayed different expression patterns under nutrient limitation. Overlap with repeats and horizontal gene transfer may be two contributing factors to the high number of PKS genes found in this species. The two high quality P. parvum genomes will serve as valuable resources for ecological, genetic, and toxicological studies of haptophytes that can be used to monitor and potentially manage harmful blooms of ichthyotoxic P. parvum in the future.
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Affiliation(s)
- Jianbo Jian
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Arisbe Silva-Núñez
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Tecnologico de Monterrey, School of Engineering and Science, Monterrey, Nuevo León, Mexico
| | - Xiaohui Li
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Bei Luo
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | - Yun Liu
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Christopher T Workman
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Thomas Ostenfeld Larsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Per Juel Hansen
- Marine Biological Section, University of Copenhagen, Helsingør, Denmark
| | - Eva C Sonnenschein
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Department of Biosciences, Swansea University, Swansea, United Kingdom.
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Schomaker RA, Dudycha JL. De novo transcriptome assembly of the green alga Ankistrodesmus falcatus. PLoS One 2021; 16:e0251668. [PMID: 33989339 PMCID: PMC8121315 DOI: 10.1371/journal.pone.0251668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/30/2021] [Indexed: 01/11/2023] Open
Abstract
Ankistrodesmus falcatus is a globally distributed freshwater chlorophyte that is a candidate for biofuel production, is used to study the effects of toxins on aquatic communities, and is used as food in zooplankton research. Each of these research fields is transitioning to genomic tools. We created a reference transcriptome for of A. falcatus using NextGen sequencing and de novo assembly methods including Trinity, Velvet-Oases, and EvidentialGene. The assembled transcriptome has a total of 17,997 contigs, an N50 value of 2,462, and a GC content of 64.8%. BUSCO analysis recovered 83.3% of total chlorophyte BUSCOs and 82.5% of the eukaryotic BUSCOs. A portion (7.9%) of these supposedly single-copy genes were found to have transcriptionally active, distinct duplicates. We annotated the assembly using the dammit annotation pipeline, resulting in putative functional annotation for 68.89% of the assembly. Using available rbcL sequences from 16 strains (10 species) of Ankistrodesmus, we constructed a neighbor-joining phylogeny to illustrate genetic distances of our A. falcatus strain to other members of the genus. This assembly will be valuable for researchers seeking to identify Ankistrodesmus sequences in metatranscriptomic and metagenomic field studies and in experiments where separating expression responses of zooplankton and their algal food sources through bioinformatics is important.
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Affiliation(s)
- Rachel A Schomaker
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States of America
| | - Jeffry L Dudycha
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States of America
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Rizkallah MR, Frickenhaus S, Trimborn S, Harms L, Moustafa A, Benes V, Gäbler-Schwarz S, Beszteri S. Deciphering Patterns of Adaptation and Acclimation in the Transcriptome of Phaeocystis antarctica to Changing Iron Conditions 1. JOURNAL OF PHYCOLOGY 2020; 56:747-760. [PMID: 32068264 DOI: 10.1111/jpy.12979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The haptophyte Phaeocystis antarctica is endemic to the Southern Ocean, where iron supply is sporadic and its availability limits primary production. In iron fertilization experiments, P. antarctica showed a prompt and steady increase in cell abundance compared to heavily silicified diatoms along with enhanced colony formation. Here we utilized a transcriptomic approach to investigate molecular responses to alleviation of iron limitation in P. antarctica. We analyzed the transcriptomic response before and after (14 h, 24 h and 72 h) iron addition to a low-iron acclimated culture. After iron addition, we observed indicators of a quick reorganization of cellular energetics, from carbohydrate catabolism and mitochondrial energy production to anabolism. In addition to typical substitution responses from an iron-economic toward an iron-sufficient state for flavodoxin (ferredoxin) and plastocyanin (cytochrome c6 ), we found other genes utilizing the same strategy involved in nitrogen assimilation and fatty acid desaturation. Our results shed light on a number of adaptive mechanisms that P. antarctica uses under low iron, including the utilization of a Cu-dependent ferric reductase system and indication of mixotrophic growth. The gene expression patterns underpin P. antarctica as a quick responder to iron addition.
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Affiliation(s)
| | - Stephan Frickenhaus
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Centre for Industrial Mathematics, University of Bremen, Bibliothekstrasse 1, 28359 Postfach 330440, 28334, Bremen, Germany
| | - Scarlett Trimborn
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Department of Marine Botany, University of Bremen, Bibliothekstrasse 1, 28359 Postfach 330440, 28334, Bremen, Germany
| | - Lars Harms
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Herrstrasse 231, 26129, Oldenburg, Germany
| | - Ahmed Moustafa
- Department of Biology, American University in Cairo, P.O. Box 74, 11835, Cairo, Egypt
| | - Vladimir Benes
- European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Steffi Gäbler-Schwarz
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Sara Beszteri
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
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6
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Hennon GMM, Dyhrman ST. Progress and promise of omics for predicting the impacts of climate change on harmful algal blooms. HARMFUL ALGAE 2020; 91:101587. [PMID: 32057337 DOI: 10.1016/j.hal.2019.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 03/10/2019] [Indexed: 06/10/2023]
Abstract
Climate change is predicted to increase the severity and prevalence of harmful algal blooms (HABs). In the past twenty years, omics techniques such as genomics, transcriptomics, proteomics and metabolomics have transformed that data landscape of many fields including the study of HABs. Advances in technology have facilitated the creation of many publicly available omics datasets that are complementary and shed new light on the mechanisms of HAB formation and toxin production. Genomics have been used to reveal differences in toxicity and nutritional requirements, while transcriptomics and proteomics have been used to explore HAB species responses to environmental stressors, and metabolomics can reveal mechanisms of allelopathy and toxicity. In this review, we explore how omics data may be leveraged to improve predictions of how climate change will impact HAB dynamics. We also highlight important gaps in our knowledge of HAB prediction, which include swimming behaviors, microbial interactions and evolution that can be addressed by future studies with omics tools. Lastly, we discuss approaches to incorporate current omics datasets into predictive numerical models that may enhance HAB prediction in a changing world. With the ever-increasing omics databases, leveraging these data for understanding climate-driven HAB dynamics will be increasingly powerful.
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Affiliation(s)
- Gwenn M M Hennon
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; College of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks, AK, United States
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States.
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7
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Johnson LK, Alexander H, Brown CT. Re-assembly, quality evaluation, and annotation of 678 microbial eukaryotic reference transcriptomes. Gigascience 2019; 8:giy158. [PMID: 30544207 PMCID: PMC6481552 DOI: 10.1093/gigascience/giy158] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/18/2018] [Accepted: 11/29/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND De novo transcriptome assemblies are required prior to analyzing RNA sequencing data from a species without an existing reference genome or transcriptome. Despite the prevalence of transcriptomic studies, the effects of using different workflows, or "pipelines," on the resulting assemblies are poorly understood. Here, a pipeline was programmatically automated and used to assemble and annotate raw transcriptomic short-read data collected as part of the Marine Microbial Eukaryotic Transcriptome Sequencing Project. The resulting transcriptome assemblies were evaluated and compared against assemblies that were previously generated with a different pipeline developed by the National Center for Genome Research. RESULTS New transcriptome assemblies contained the majority of previous contigs as well as new content. On average, 7.8% of the annotated contigs in the new assemblies were novel gene names not found in the previous assemblies. Taxonomic trends were observed in the assembly metrics. Assemblies from the Dinoflagellata showed a higher number of contigs and unique k-mers than transcriptomes from other phyla, while assemblies from Ciliophora had a lower percentage of open reading frames compared to other phyla. CONCLUSIONS Given current bioinformatics approaches, there is no single "best" reference transcriptome for a particular set of raw data. As the optimum transcriptome is a moving target, improving (or not) with new tools and approaches, automated and programmable pipelines are invaluable for managing the computationally intensive tasks required for re-processing large sets of samples with revised pipelines and ensuring a common evaluation workflow is applied to all samples. Thus, re-assembling existing data with new tools using automated and programmable pipelines may yield more accurate identification of taxon-specific trends across samples in addition to novel and useful products for the community.
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Affiliation(s)
- Lisa K Johnson
- Department of Population Health, and Reproduction, School of Veterinary Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Molecular, Cellular, and Integrative Physiology Graduate Group, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Harriet Alexander
- Department of Population Health, and Reproduction, School of Veterinary Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - C Titus Brown
- Department of Population Health, and Reproduction, School of Veterinary Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Molecular, Cellular, and Integrative Physiology Graduate Group, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Genome Center, University of California Davis, 451 Health Sciences Dr, Davis, CA 95616, USA
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8
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Comparative expression profiling reveals widespread coordinated evolution of gene expression across eukaryotes. Nat Commun 2018; 9:4963. [PMID: 30470754 PMCID: PMC6251915 DOI: 10.1038/s41467-018-07436-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/24/2018] [Indexed: 12/17/2022] Open
Abstract
Comparative studies of gene expression across species have revealed many important insights, but have also been limited by the number of species represented. Here we develop an approach to identify orthologs between highly diverged transcriptome assemblies, and apply this to 657 RNA-seq gene expression profiles from 309 diverse unicellular eukaryotes. We analyzed the resulting data for coevolutionary patterns, and identify several hundred protein complexes and pathways whose expression levels have evolved in a coordinated fashion across the trillions of generations separating these species, including many gene sets with little or no within-species co-expression across environmental or genetic perturbations. We also detect examples of adaptive evolution, for example of tRNA ligase levels to match genome-wide codon usage. In sum, we find that comparative studies from extremely diverse organisms can reveal new insights into the evolution of gene expression, including coordinated evolution of some of the most conserved protein complexes in eukaryotes. Gene pairs that are coexpressed across various environmental conditions in multiple species suggest functional similarity. Here the authors analyze patterns of gene expression co-evolution across diverse eukaryotes, and identify hundreds of protein complexes and pathways whose gene expression levels have co-evolved since their ancient divergence.
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Hu SK, Liu Z, Alexander H, Campbell V, Connell PE, Dyhrman ST, Heidelberg KB, Caron DA. Shifting metabolic priorities among key protistan taxa within and below the euphotic zone. Environ Microbiol 2018; 20:2865-2879. [PMID: 29708635 DOI: 10.1111/1462-2920.14259] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/12/2022]
Abstract
A metatranscriptome study targeting the protistan community was conducted off the coast of Southern California, at the San Pedro Ocean Time-series station at the surface, 150 m (oxycline), and 890 m to link putative metabolic patterns to distinct protistan lineages. Comparison of relative transcript abundances revealed depth-related shifts in the nutritional modes of key taxonomic groups. Eukaryotic gene expression in the sunlit surface environment was dominated by phototrophs, such as diatoms and chlorophytes, and high abundances of transcripts associated with synthesis pathways (e.g., photosynthesis, carbon fixation, fatty acid synthesis). Sub-euphotic depths (150 and 890 m) exhibited strong contributions from dinoflagellates and ciliates, and were characterized by transcripts relating to digestion or intracellular nutrient recycling (e.g., breakdown of fatty acids and V-type ATPases). These transcriptional patterns underlie the distinct nutritional modes of ecologically important protistan lineages that drive marine food webs, and provide a framework to investigate trophic dynamics across diverse protistan communities.
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Affiliation(s)
- Sarah K Hu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Zhenfeng Liu
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Harriet Alexander
- Department of Population Health and Reproduction, University of California Davis, Davis, CA, USA
| | - Victoria Campbell
- Division Allergy and Infectious Diseases, UW Medicine, Seattle, WA, USA
| | - Paige E Connell
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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10
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Bharudin I, Abu Bakar MF, Hashim NHF, Mat Isa MN, Alias H, Firdaus-Raih M, Md Illias R, Najimudin N, Mahadi NM, Abu Bakar FD, Abdul Murad AM. Unravelling the adaptation strategies employed by Glaciozyma antarctica PI12 on Antarctic sea ice. MARINE ENVIRONMENTAL RESEARCH 2018; 137:169-176. [PMID: 29598997 DOI: 10.1016/j.marenvres.2018.03.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/09/2018] [Accepted: 03/19/2018] [Indexed: 06/08/2023]
Abstract
Glaciozyma antarctica PI12, is a psychrophilic yeast isolated from Antarctic sea. In this work, Expressed Sequence Tags (EST) from cells exposed to three different temperatures; 15 °C, 0 °C and -12 °C were generated to identify genes associated with cold adaptation. A total of 5376 clones from each library were randomly picked and sequenced. Comparative analyses from the resulting ESTs in each condition identified several groups of genes required for cold adaptation. Additionally, 319 unique transcripts that encoded uncharacterised functions were identified in the -12 °C library and are currently unique to G. antarctica. Gene expression analysis using RT-qPCR revealed two of the unknown genes to be up-regulated at -12 °C compared to 0 °C and 15 °C. These findings further contribute to the collective knowledge into G. antarctica cold adaptation and as a resource for understanding the ecological and physiological tolerance of psychrophilic microbes in general.
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Affiliation(s)
- Izwan Bharudin
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia.
| | | | - Noor Haza Fazlin Hashim
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Mohd Noor Mat Isa
- Malaysia Genome Institute, Jalan Bangi Lama, 43000, Kajang, Selangor, Malaysia
| | - Halimah Alias
- Malaysia Genome Institute, Jalan Bangi Lama, 43000, Kajang, Selangor, Malaysia
| | - Mohd Firdaus-Raih
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia; Institute of Systems Biology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Rosli Md Illias
- Department of Biosciences Engineering, Faculty of Chemical & Natural Resources Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Nazalan Najimudin
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Nor Muhammad Mahadi
- Malaysia Genome Institute, Jalan Bangi Lama, 43000, Kajang, Selangor, Malaysia
| | - Farah Diba Abu Bakar
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
| | - Abdul Munir Abdul Murad
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
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11
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Berdjeb L, Parada A, Needham DM, Fuhrman JA. Short-term dynamics and interactions of marine protist communities during the spring-summer transition. ISME JOURNAL 2018; 12:1907-1917. [PMID: 29599520 DOI: 10.1038/s41396-018-0097-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 02/15/2018] [Accepted: 02/26/2018] [Indexed: 11/09/2022]
Abstract
We examined the short-term variability, by daily to weekly sampling, of protist assemblages from March to July in surface water of the San Pedro Ocean Time-series station (eastern North Pacific), by V4 Illumina sequencing of the 18S rRNA gene. The sampling period encompassed a spring bloom followed by progression to summer conditions. Several protistan taxa displayed sharp increases and declines, with whole community Bray-Curtis dissimilarities of adjacent days being 66% in March and 40% in May. High initial abundance of parasitic Cercozoa Cryothecomonas longipes and Protaspis grandis coincided with a precipitous decline of blooming Pseudo-nitzschia diatoms, possibly suggesting their massive infection by these parasites; these cercozoans were hardly detectable afterwards. Canonical correspondence analysis indicated a limited predictability of community variability from environmental factors. This indicates that other factors are relevant in explaining changes in protist community composition at short temporal scales, such as interspecific relationships, stochastic processes, mixing with adjacent water, or advection of patches with different protist communities. Association network analysis revealed that interactions between the many parasitic OTUs and other taxa were overwhelmingly positive and suggest that although sometimes parasites may cause a crash of host populations, they may often follow their hosts and do not regularly cause enough mortality to potentially create negative correlations at the daily to weekly time scales we studied.
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Affiliation(s)
- Lyria Berdjeb
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Alma Parada
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David M Needham
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
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12
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Carvalho EL, Maciel LF, Macedo PE, Dezordi FZ, Abreu MET, Victória FDC, Pereira AB, Boldo JT, Wallau GDL, Pinto PM. De novo Assembly and Annotation of the Antarctic Alga Prasiola crispa Transcriptome. Front Mol Biosci 2018; 4:89. [PMID: 29359133 PMCID: PMC5766667 DOI: 10.3389/fmolb.2017.00089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/05/2017] [Indexed: 11/13/2022] Open
Affiliation(s)
- Evelise L Carvalho
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | - Lucas F Maciel
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | - Pablo E Macedo
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | - Filipe Z Dezordi
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | - Maria E T Abreu
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | | | - Antônio B Pereira
- Núcleo de Estudos da Vegetação Antártica, Federal University of Pampa, São Gabriel, Brazil
| | - Juliano T Boldo
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
| | | | - Paulo M Pinto
- Applied Proteomics Laboratory, Federal University of Pampa, São Gabriel, Brazil
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13
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Graupner N, Boenigk J, Bock C, Jensen M, Marks S, Rahmann S, Beisser D. Functional and phylogenetic analysis of the core transcriptome of Ochromonadales. METABARCODING AND METAGENOMICS 2017. [DOI: 10.3897/mbmg.1.19862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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14
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Haley ST, Alexander H, Juhl AR, Dyhrman ST. Transcriptional response of the harmful raphidophyte Heterosigma akashiwo to nitrate and phosphate stress. HARMFUL ALGAE 2017; 68:258-270. [PMID: 28962986 DOI: 10.1016/j.hal.2017.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
The marine eukaryotic alga Heterosigma akashiwo (Raphidophyceae) is known for forming ichthyotoxic harmful algal blooms (HABs). In the past 50 years, H. akashiwo blooms have increased, occurring globally in highly eutrophic coastal and estuarine systems. These systems often incur dramatic physicochemical changes, including macronutrient (nitrogen and phosphorus) enrichment and depletion, on short timescales. Here, H. akashiwo cultures grown under nutrient replete, low N and low P growth conditions were examined for changes in biochemical and physiological characteristics in concert with transcriptome sequencing to provide a mechanistic perspective on the metabolic processes involved in responding to N and P stress. There was a marked difference in the overall transcriptional pattern between low N and low P transcriptomes. Both nutrient stresses led to significant changes in the abundance of thousands of contigs related to a wide diversity of metabolic pathways, with limited overlap between the transcriptomic responses to low N and low P. Enriched contigs under low N included many related to nitrogen metabolism, acquisition, and transport. In addition, metabolic modules like photosynthesis and carbohydrate metabolism changed significantly under low N, coincident with treatment-specific changes in photosynthetic efficiency and particulate carbohydrate content. P-specific contigs responsible for P transport and organic P use were more enriched in the low P treatment than in the replete control and low N treatment. These results provide new insight into the genetic mechanisms that distinguish how this HAB species responds to these two common nutrient stresses, and the results can inform future field studies, linking transcriptional patterns to the physiological ecology of H. akashiwo in situ.
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Affiliation(s)
- Sheean T Haley
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA
| | - Harriet Alexander
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Andrew R Juhl
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA; Columbia University, Department of Earth and Environmental Sciences, Palisades, NY, USA
| | - Sonya T Dyhrman
- Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY, USA; Columbia University, Department of Earth and Environmental Sciences, Palisades, NY, USA.
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15
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Harke MJ, Juhl AR, Haley ST, Alexander H, Dyhrman ST. Conserved Transcriptional Responses to Nutrient Stress in Bloom-Forming Algae. Front Microbiol 2017; 8:1279. [PMID: 28769884 PMCID: PMC5513979 DOI: 10.3389/fmicb.2017.01279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/26/2017] [Indexed: 11/13/2022] Open
Abstract
The concentration and composition of bioavailable nitrogen (N) and phosphorus (P) in the upper ocean shape eukaryotic phytoplankton communities and influence their physiological responses. Phytoplankton are known to exhibit similar physiological responses to limiting N and P conditions such as decreased growth rates, chlorosis, and increased assimilation of N and P. Are these responses similar at the molecular level across multiple species? To interrogate this question, five species from biogeochemically important, bloom-forming taxa (Bacillariophyta, Dinophyta, and Haptophyta) were grown under similar low N, low P, and replete nutrient conditions to identify transcriptional patterns and associated changes in biochemical pools related to N and P stress. Metabolic profiles, revealed through the transcriptomes of these taxa, clustered together based on species rather than nutrient stressor, suggesting that the global metabolic response to nutrient stresses was largely, but not exclusively, species-specific. Nutrient stress led to few transcriptional changes in the two dinoflagellates, consistent with other research. An orthologous group analysis examined functionally conserved (i.e., similarly changed) responses to nutrient stress and therefore focused on the diatom and haptophytes. Most conserved ortholog changes were specific to a single nutrient treatment, but a small number of orthologs were similarly changed under both N and P stress in 2 or more species. Many of these orthologs were related to photosynthesis and may represent generalized stress responses. A greater number of orthologs were conserved across more than one species under low P compared to low N. Screening the conserved orthologs for functions related to N and P metabolism revealed increased relative abundance of orthologs for nitrate, nitrite, ammonium, and amino acid transporters under N stress, and increased relative abundance of orthologs related to acquisition of inorganic and organic P substrates under P stress. Although the global transcriptional responses were dominated by species-specific changes, the analysis of conserved responses revealed functional similarities in resource acquisition pathways among different phytoplankton taxa. This overlap in nutrient stress responses observed among species may be useful for tracking the physiological ecology of phytoplankton field populations.
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Affiliation(s)
- Matthew J Harke
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States
| | - Andrew R Juhl
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States.,Department of Earth and Environmental Sciences, Columbia UniversityPalisades, NY, United States
| | - Sheean T Haley
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States
| | - Harriet Alexander
- Department of Population Health and Reproduction, University of California, DavisDavis, CA, United States
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia UniversityPalisades, NY, United States.,Department of Earth and Environmental Sciences, Columbia UniversityPalisades, NY, United States
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16
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Beisser D, Graupner N, Bock C, Wodniok S, Grossmann L, Vos M, Sures B, Rahmann S, Boenigk J. Comprehensive transcriptome analysis provides new insights into nutritional strategies and phylogenetic relationships of chrysophytes. PeerJ 2017; 5:e2832. [PMID: 28097055 PMCID: PMC5228505 DOI: 10.7717/peerj.2832] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 11/27/2016] [Indexed: 02/02/2023] Open
Abstract
Background Chrysophytes are protist model species in ecology and ecophysiology and important grazers of bacteria-sized microorganisms and primary producers. However, they have not yet been investigated in detail at the molecular level, and no genomic and only little transcriptomic information is available. Chrysophytes exhibit different trophic modes: while phototrophic chrysophytes perform only photosynthesis, mixotrophs can gain carbon from bacterial food as well as from photosynthesis, and heterotrophs solely feed on bacteria-sized microorganisms. Recent phylogenies and megasystematics demonstrate an immense complexity of eukaryotic diversity with numerous transitions between phototrophic and heterotrophic organisms. The question we aim to answer is how the diverse nutritional strategies, accompanied or brought about by a reduction of the plasmid and size reduction in heterotrophic strains, affect physiology and molecular processes. Results We sequenced the mRNA of 18 chrysophyte strains on the Illumina HiSeq platform and analysed the transcriptomes to determine relations between the trophic mode (mixotrophic vs. heterotrophic) and gene expression. We observed an enrichment of genes for photosynthesis, porphyrin and chlorophyll metabolism for phototrophic and mixotrophic strains that can perform photosynthesis. Genes involved in nutrient absorption, environmental information processing and various transporters (e.g., monosaccharide, peptide, lipid transporters) were present or highly expressed only in heterotrophic strains that have to sense, digest and absorb bacterial food. We furthermore present a transcriptome-based alignment-free phylogeny construction approach using transcripts assembled from short reads to determine the evolutionary relationships between the strains and the possible influence of nutritional strategies on the reconstructed phylogeny. We discuss the resulting phylogenies in comparison to those from established approaches based on ribosomal RNA and orthologous genes. Finally, we make functionally annotated reference transcriptomes of each strain available to the community, significantly enhancing publicly available data on Chrysophyceae. Conclusions Our study is the first comprehensive transcriptomic characterisation of a diverse set of Chrysophyceaen strains. In addition, we showcase the possibility of inferring phylogenies from assembled transcriptomes using an alignment-free approach. The raw and functionally annotated data we provide will prove beneficial for further examination of the diversity within this taxon. Our molecular characterisation of different trophic modes presents a first such example.
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Affiliation(s)
- Daniela Beisser
- Genome Informatics, University of Duisburg-Essen, Essen, Germany
| | - Nadine Graupner
- Biodiversity, University of Duisburg-Essen, Essen, Germany.,Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Christina Bock
- Biodiversity, University of Duisburg-Essen, Essen, Germany.,Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Sabina Wodniok
- Biodiversity, University of Duisburg-Essen, Essen, Germany.,Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Lars Grossmann
- Biodiversity, University of Duisburg-Essen, Essen, Germany.,Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Matthijs Vos
- Theoretical and Applied Biodiversity, Ruhr-University Bochum, Bochum, Germany
| | - Bernd Sures
- Aquatic Ecology, University of Duisburg-Essen, Essen, Germany
| | - Sven Rahmann
- Genome Informatics, University of Duisburg-Essen, Essen, Germany
| | - Jens Boenigk
- Biodiversity, University of Duisburg-Essen, Essen, Germany.,Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
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17
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Hovde BT, Deodato CR, Hunsperger HM, Ryken SA, Yost W, Jha RK, Patterson J, Monnat RJ, Barlow SB, Starkenburg SR, Cattolico RA. Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae). PLoS Genet 2015; 11:e1005469. [PMID: 26397803 PMCID: PMC4580454 DOI: 10.1371/journal.pgen.1005469] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 07/27/2015] [Indexed: 12/11/2022] Open
Abstract
Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide synthase/non-ribosomal peptide synthase gene complex reported for an algal species, and encodes potential anti-microbial peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two “red” RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes. Microalgae are important contributors to global ecological balance, and process nearly half of the world’s carbon each year. Additionally, these organisms are deeply rooted in the earths’ evolutionary history. To better understand why algae are such strong survivors in aquatic environments and to better understand their contribution to global ecology, we sequenced the genome of a microalga that is abundant in both fresh and salt water environments, but poorly represented by current genomic information. We identify protein-coding genes responsible for the synthesis of potential toxins as well as those that produce antibiotics, and describe gene products that enhanced the ability of the alga to use light energy. We observed that a day-night cycle, similar to that found in natural environments, significantly impacts the expression of algal genes whose products are responsible for synthesizing fats—a rich source of nutrition for many other organisms.
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Affiliation(s)
- Blake T. Hovde
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- * E-mail: (BTH); (RAC)
| | - Chloe R. Deodato
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Heather M. Hunsperger
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Scott A. Ryken
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Will Yost
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Ramesh K. Jha
- Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Johnathan Patterson
- Department of Biology, University of Washington, Seattle, Washington, United States of America
| | - Raymond J. Monnat
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- University of Washington, Department of Pathology, Seattle, Washington, United States of America
| | - Steven B. Barlow
- Electron Microscope Facility, San Diego State University, San Diego, California, United States of America
| | - Shawn R. Starkenburg
- Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Rose Ann Cattolico
- Department of Biology, University of Washington, Seattle, Washington, United States of America
- * E-mail: (BTH); (RAC)
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18
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Liu Z, Koid AE, Terrado R, Campbell V, Caron DA, Heidelberg KB. Changes in gene expression of Prymnesium parvum induced by nitrogen and phosphorus limitation. Front Microbiol 2015; 6:631. [PMID: 26157435 PMCID: PMC4478897 DOI: 10.3389/fmicb.2015.00631] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/10/2015] [Indexed: 11/25/2022] Open
Abstract
Prymnesium parvum is a globally distributed prymnesiophyte alga commonly found in brackish water marine ecosystems and lakes. It possesses a suite of toxins with ichthyotoxic, cytotoxic and hemolytic effects which, along with its mixotrophic nutritional capabilities, allows it to form massive Ecosystem Disruptive Algal Blooms (EDABs). While blooms of high abundance coincide with high levels of nitrogen (N) and phosphorus (P), reports of field and laboratory studies have noted that P. parvum toxicity appears to be augmented at high N:P ratios or P-limiting conditions. Here we present the results of a comparative analysis of P. parvum RNA-Seq transcriptomes under nutrient replete conditions, and N or P deficiency to understand how this organism responds at the transcriptional level to varying nutrient conditions. In nutrient limited conditions we found diverse transcriptional responses for genes involved in nutrient uptake, protein synthesis and degradation, photosynthesis, and toxin production. As anticipated, when either N or P was limiting, transcription levels of genes encoding transporters for the respective nutrient were higher than those under replete condition. Ribosomal and lysosomal protein genes were expressed at higher levels under either nutrient-limited condition compared to the replete condition. Photosynthesis genes and polyketide synthase genes were more highly expressed under P-limitation but not under N-limitation. These results highlight the ability of P. parvum to mount a coordinated and varied cellular and physiological response to nutrient limitation. Results also provide potential marker genes for further evaluating the physiological response and toxin production of P. parvum populations during bloom formation or to changing environmental conditions.
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Affiliation(s)
- Zhenfeng Liu
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Amy E Koid
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Ramon Terrado
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Victoria Campbell
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California Los Angeles, CA, USA
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19
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Liu Z, Jones AC, Campbell V, Hambright KD, Heidelberg KB, Caron DA. Gene expression in the mixotrophic prymnesiophyte, Prymnesium parvum, responds to prey availability. Front Microbiol 2015; 6:319. [PMID: 25941521 PMCID: PMC4403553 DOI: 10.3389/fmicb.2015.00319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 03/30/2015] [Indexed: 12/25/2022] Open
Abstract
The mixotrophic prymnesiophyte, Prymnesium parvum, is a widely distributed alga with significant ecological importance. It produces toxins and can form ecosystem disruptive blooms that result in fish kills and changes in planktonic food web structure. However, the relationship between P. parvum and its prey on the molecular level is poorly understood. In this study, we used RNA-Seq technology to study changes in gene transcription of P. parvum in three treatments with different microbial populations available as potential prey: axenic P. parvum (no prey), bacterized P. paruvm, and axenic P. parvum with ciliates added as prey. Thousands of genes were differentially expressed among the three treatments. Most notably, transcriptome data indicated that P. parvum obtained organic carbon, including fatty acids, from both bacteria and ciliate prey for energy and cellular building blocks. The data also suggested that different prey provided P. parvum with macro- and micro-nutrients, namely organic nitrogen in the form of amino acids from ciliates, and iron from bacteria. However, both transcriptomic data and growth experiments indicated that P. parvum did not grow faster in the presence of prey despite the gains in nutrients, although algal abundances attained in culture were slightly greater in the presence of prey. The relationship between phototrophy, heterotrophy and growth of P. parvum is discussed.
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Affiliation(s)
- Zhenfeng Liu
- Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
| | - Adriane C. Jones
- Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
| | - Victoria Campbell
- Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
| | - K. David Hambright
- Program in Ecology and Evolutionary Biology, Department of Biology, University of OklahomaNorman, OK, USA
| | - Karla B. Heidelberg
- Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
| | - David A. Caron
- Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
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