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Vences M, Sachs M, Irisarri I, Bartels F, Eriksson PF, Künzel S, Kurabayashi A, Laugen AT, Vegso ZT, Bishop CD, Kerney R, Arndt H. Phylotranscriptomic relationships of the Oophila clade of green algae associated to amphibian egg masses. Mol Phylogenet Evol 2024; 200:108165. [PMID: 39117294 DOI: 10.1016/j.ympev.2024.108165] [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: 01/11/2024] [Revised: 06/26/2024] [Accepted: 07/31/2024] [Indexed: 08/10/2024]
Abstract
Green algae usually assigned to the genus Oophila are known to colonize egg capsules of amphibian egg masses across the Nearctic and Palearctic regions. We study the phylogenetic relationships of these algae using a phylotranscriptomic data set of 76 protein-coding single-copy nuclear genes. Our data set includes novel RNAseq data for six amphibian-associated and five free-living green algae, and draft genomes of two of the latter. Within the Oophila clade (nested within Moewusinia), we find samples from two European frogs (Rana dalmatina and R. temporaria) closely related to those of the North American frog R. aurora (Oophila subclade III). An isolate from the North American R. sylvatica (subclade IV) appears to be sister to the Japanese isolate from the salamander Hynobius nigrescens (subclade J1), and subclade I algae from Ambystoma maculatum are sister to all other lineages in the Oophila clade. Two free-living algae (Chlamydomonas nasuta and Cd. pseudogloeogama) are nested within the Oophila clade, and a strain of the type species of Chlorococcum (Cc. infusionum) is related to this assemblage. Our phylotranscriptomic tree suggests that recognition of different species within the Oophila clade ("clade B" of earlier studies) is warranted, and calls for a comprehensive taxonomic revision of Moewusinia.
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Affiliation(s)
- Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
| | - Maria Sachs
- Institute of Zoology, University of Cologne, Zülpicherstr. 47b, 50674 Köln, Germany
| | - Iker Irisarri
- Section Phylogenomics, Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
| | - Fabian Bartels
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany
| | - Pontus F Eriksson
- Department of Natural Sciences, University of Agder, Kristiansand, Norway
| | - Sven Künzel
- Department of Evolutionary Genetics, Max Planck Institute, for Evolutionary Biology, 24306 Plön, Germany
| | - Atsushi Kurabayashi
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany; Ise City, Mie Prefecture, Japan
| | - Ane T Laugen
- Department of Natural Sciences, University of Agder, Kristiansand, Norway
| | - Zachary T Vegso
- Department of Biological Sciences, California State Polytechnic University, Humboldt, 1 Harpst St, Arcata, CA 95521, USA
| | - Cory D Bishop
- Department of Biology, St. Francis-Xavier University, 2320 Notre Dame Avenue, Antigonish, Nova Scotia B2G 2W5, Canada
| | - Ryan Kerney
- Department of Biology, Gettysburg College, Gettysburg, PA, USA
| | - Hartmut Arndt
- Institute of Zoology, University of Cologne, Zülpicherstr. 47b, 50674 Köln, Germany
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Nikulin VY, Nikulin AY, Gontcharov AA, Bagmet VB, Abdullin SR. Oogamochlamys kurilensis sp. nov. (Chlorophyta, Volvocales) from the Soils of Iturup Island (Sakhalin Region, Russia). PLANTS (BASEL, SWITZERLAND) 2023; 12:3350. [PMID: 37836090 PMCID: PMC10574126 DOI: 10.3390/plants12193350] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/09/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023]
Abstract
A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade (sensu Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus Oogamochlamys (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids' shape. Although a concept of the genus Oogamochlamys has been compromised in recent phylogenetic analysis based on the SSU rDNA sequence data and its likely affinity to anisogamous Chlamydomonas allensworthii, we described the strain from Iturup Island as Oogamochlamys kurilensis sp. nov.
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Affiliation(s)
- Vyacheslav Yu. Nikulin
- Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, 159, 100-Letia Vladivostoka Prospect, Vladivostok 690022, Russia; (A.A.G.); (V.B.B.); (S.R.A.)
| | - Arthur Yu. Nikulin
- Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, 159, 100-Letia Vladivostoka Prospect, Vladivostok 690022, Russia; (A.A.G.); (V.B.B.); (S.R.A.)
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Barcytė D, Pusztai M, Škaloud P, Eliáš M. When you Like Other Algae: Adglutina synurophila gen. et sp. nov. (Moewusinia, Chlorophyceae), a Clingy Green Microalga Associated with Synura Colonies. Protist 2022; 173:125858. [DOI: 10.1016/j.protis.2022.125858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 01/21/2022] [Accepted: 01/27/2022] [Indexed: 11/29/2022]
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Pascoal PV, Ribeiro DM, Cereijo CR, Santana H, Nascimento RC, Steindorf AS, Calsing LCG, Formighieri EF, Brasil BSAF. Biochemical and phylogenetic characterization of the wastewater tolerant Chlamydomonas biconvexa Embrapa|LBA40 strain cultivated in palm oil mill effluent. PLoS One 2021; 16:e0249089. [PMID: 33826653 PMCID: PMC8026047 DOI: 10.1371/journal.pone.0249089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/11/2021] [Indexed: 11/19/2022] Open
Abstract
The increasing demand for water, food and energy poses challenges for the world´s sustainability. Tropical palm oil is currently the major source of vegetable oil worldwide with a production that exceeds 55 million tons per year, while generating over 200 million tons of palm oil mill effluent (POME). It could potentially be used as a substrate for production of microalgal biomass though. In this study, the microalgal strain Chlamydomonas biconvexa Embrapa|LBA40, originally isolated from a sugarcane vinasse stabilization pond, was selected among 17 strains tested for growth in POME retrieved from anaerobic ponds of a palm oil industrial plant located within the Amazon rainforest region. During cultivation in POME, C. biconvexa Embrapa|LBA40 biomass productivity reached 190.60 mgDW • L-1 • d-1 using 15L airlift flat plate photobioreactors. Carbohydrates comprised the major fraction of algal biomass (31.96%), while the lipidic fraction reached up to 11.3% of dry mass. Reductions of 99% in ammonium and nitrite, as well as 98% reduction in phosphate present in POME were detected after 5 days of algal cultivation. This suggests that the aerobic pond stage, usually used in palm oil industrial plants to reduce POME inorganic load, could be substituted by high rate photobioreactors, significantly reducing the time and area requirements for wastewater treatment. In addition, the complete mitochondrial genome of C. biconvexa Embrapa|LBA40 strain was sequenced, revealing a compact mitogenome, with 15.98 kb in size, a total of 14 genes, of which 9 are protein coding genes. Phylogenetic analysis confirmed the strain taxonomic status within the Chlamydomonas genus, opening up opportunities for future genetic modification and molecular breeding programs in these species.
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Affiliation(s)
- Patrícia Verdugo Pascoal
- Embrapa Agroenergia, Brasília, Distrito Federal, Brazil
- Universidade Federal da Bahia, Salvador, Bahia, Brazil
| | - Dágon Manoel Ribeiro
- Embrapa Agroenergia, Brasília, Distrito Federal, Brazil
- Universidade de Brasília, Brasília, Distrito Federal, Brazil
- Universidade Zambeze, Sofala, Mozambique
| | | | - Hugo Santana
- Embrapa Agroenergia, Brasília, Distrito Federal, Brazil
| | - Rodrigo Carvalho Nascimento
- Embrapa Agroenergia, Brasília, Distrito Federal, Brazil
- Universidade Federal do Tocantins, Gurupi, Tocantins, Brazil
| | | | | | | | - Bruno S. A. F. Brasil
- Embrapa Agroenergia, Brasília, Distrito Federal, Brazil
- Universidade Federal da Bahia, Salvador, Bahia, Brazil
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Carrasco Flores D, Fricke M, Wesp V, Desirò D, Kniewasser A, Hölzer M, Marz M, Mittag M. A marine Chlamydomonas sp. emerging as an algal model. JOURNAL OF PHYCOLOGY 2021; 57:54-69. [PMID: 33043442 DOI: 10.1111/jpy.13083] [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: 06/05/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
The freshwater microalga Chlamydomonas reinhardtii, which lives in wet soil, has served for decades as a model for numerous biological processes, and many tools have been introduced for this organism. Here, we have established a stable nuclear transformation for its marine counterpart, Chlamydomonas sp. SAG25.89, by fusing specific cis-acting elements from its Actin gene with the gene providing hygromycin resistance and using an elaborated electroporation protocol. Like C. reinhardtii, Chlamydomonas sp. has a high GC content, allowing reporter genes and selection markers to be applicable in both organisms. Chlamydomonas sp. grows purely photoautotrophically and requires ammonia as a nitrogen source because its nuclear genome lacks some of the genes required for nitrogen metabolism. Interestingly, it can grow well under both low and very high salinities (up to 50 g · L-1 ) rendering it as a model for osmotolerance. We further show that Chlamydomonas sp. grows well from 15 to 28°C, but halts its growth at 32°C. The genome of Chlamydomonas sp. contains some gene homologs the expression of which is regulated according to the ambient temperatures and/or confer thermal acclimation in C. reinhardtii. Thus, knowledge of temperature acclimation can now be compared to the marine species. Furthermore, Chlamydomonas sp. can serve as a model for studying marine microbial interactions and for comparing mechanisms in freshwater and marine environments. Chlamydomonas sp. was previously shown to be immobilized rapidly by a cyclic lipopeptide secreted from the antagonistic bacterium Pseudomonas protegens PF-5, which deflagellates C. reinhardtii.
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Affiliation(s)
- David Carrasco Flores
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, 07743, Germany
| | - Markus Fricke
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University, Jena, 07743, Germany
| | - Valentin Wesp
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, 07743, Germany
| | - Daniel Desirò
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University, Jena, 07743, Germany
| | - Anja Kniewasser
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, 07743, Germany
| | - Martin Hölzer
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University, Jena, 07743, Germany
| | - Manja Marz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University, Jena, 07743, Germany
- FLI, Leibniz Institute for Age Research, Beutenbergstr. 11, Jena, 07745, Germany
| | - Maria Mittag
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, 07743, Germany
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Biodiversity of Algae and Cyanobacteria in Biological Soil Crusts Collected Along a Climatic Gradient in Chile Using an Integrative Approach. Microorganisms 2020; 8:microorganisms8071047. [PMID: 32674483 PMCID: PMC7409284 DOI: 10.3390/microorganisms8071047] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/15/2020] [Accepted: 06/26/2020] [Indexed: 11/26/2022] Open
Abstract
Biocrusts are associations of various prokaryotic and eukaryotic microorganisms in the top millimeters of soil, which can be found in every climate zone on Earth. They stabilize soils and introduce carbon and nitrogen into this compartment. The worldwide occurrence of biocrusts was proven by numerous studies in Europe, Africa, Asia and North America, leaving South America understudied. Using an integrative approach, which combines morphological and molecular characters (small subunit rRNA and ITS region), we examined the diversity of key biocrust photosynthetic organisms at four sites along the latitudinal climate gradient in Chile. The most northern study site was located in the Atacama Desert (arid climate), followed by open shrubland (semiarid climate), a dry forest region (Mediterranean climate) and a mixed broad leaved-coniferous forest (temperate climate) in the south. The lowest species richness was recorded in the desert (18 species), whereas the highest species richness was observed in the Mediterranean zone (40 species). Desert biocrusts were composed exclusively of single-celled Chlorophyta algae, followed by cyanobacteria. Chlorophyta, Streptophyta and cyanobacteria dominated semiarid biocrusts, whereas Mediterranean and temperate Chilean biocrusts were composed mostly of Chlorophyta, Streptophyta and Ochrophyta. Our investigation of Chilean biocrust suggests high biodiversity of South American biocrust phototrophs.
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Matsuzaki R, Nozaki H, Takeuchi N, Hara Y, Kawachi M. Taxonomic re-examination of "Chloromonas nivalis (Volvocales, Chlorophyceae) zygotes" from Japan and description of C. muramotoi sp. nov. PLoS One 2019; 14:e0210986. [PMID: 30677063 PMCID: PMC6345437 DOI: 10.1371/journal.pone.0210986] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/06/2019] [Indexed: 11/19/2022] Open
Abstract
Recent molecular data has strongly suggested that field-collected cysts of snow algae that are morphologically identifiable as the zygotes of Chloromonas nivalis are composed of multiple species. Motile vegetative cells, however, have not been directly obtained from these cysts because of the difficulties involved in inducing their germination. Recently, our comparative molecular analyses, using both field-collected and cultured materials, demonstrated that one Japanese lineage of "C. nivalis zygotes" belongs to C. miwae. Herein, we examined another Japanese lineage of field-collected "C. nivalis zygotes" and a new strain originating from Japan. Our molecular data demonstrated that these two different life cycle stages are conspecific, and that they represent a new species that we herein describe as C. muramotoi sp. nov., based on the vegetative and asexual morphological characteristics of the strain. Multigene phylogenetic analyses showed that this new species was sister to C. miwae. Scanning electron microscopy demonstrated that the cysts of C. muramotoi are different from those of C. miwae, based on the arrangement of the flanges developing on the cell wall.
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Affiliation(s)
- Ryo Matsuzaki
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Nozomu Takeuchi
- Department of Earth Sciences, Graduate School of Science, Chiba University, Yayoicho, Inage ward, Chiba, Chiba, Japan
| | - Yoshiaki Hara
- Institute of Arts and Sciences, Yamagata University, Kojirakawa, Yamagata, Yamagata, Japan
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, Japan
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Improved taxon sampling and multigene phylogeny of unicellular chlamydomonads closely related to the colonial volvocalean lineage Tetrabaenaceae-Goniaceae-Volvocaceae (Volvocales, Chlorophyceae). Mol Phylogenet Evol 2018; 130:1-8. [PMID: 30266459 DOI: 10.1016/j.ympev.2018.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 09/13/2018] [Accepted: 09/21/2018] [Indexed: 11/23/2022]
Abstract
In the green algal order Volvocales (Chlorophyceae), flagellate colonial forms have evolved at least four times. One of these colonial lineages, Tetrabaenaceae-Goniaceae-Volvocaceae (TGV), which belongs to the clade Reinhardtinia, is closely related to several unicellular chlamydomonads in the genera Chlamydomonas and Vitreochlamys. However, the unicellular sister of TGV has not been specified. Here, the largest ever 18S rRNA phylogenetic tree of Reinhardtinia was constructed including several newly isolated chlamydomonads, and a clade (core-Reinhardtinia) including 32 unicellular lineages and three colonial families were recognized. Interrelationships within core-Reinhardtinia were barely resolved in the tree, and therefore combined 18S-atpB-psaA-psaB-psbC-rbcL gene phylogenetic analyses were performed with selected representatives of 29 of the 32 unicellular lineages and three colonial families. The 29 unicellular lineages were clustered into five metaclades and an unassigned lineage; the metaclade that includes Chlamydomonas pila was resolved, with moderate support, as the sister clade to TGV. To examine possible biases from specific gene(s), long-branch taxa, and the heterogeneous base composition, phylogenetic analyses using several smaller data sets were also performed. Light microscopy of C. pila and its relatives indicated that any early steps towards colony evolution appeared after divergence of TGV from the C. pila lineage.
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Puente-Sánchez F, Díaz S, Penacho V, Aguilera A, Olsson S. Basis of genetic adaptation to heavy metal stress in the acidophilic green alga Chlamydomonas acidophila. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 200:62-72. [PMID: 29727772 DOI: 10.1016/j.aquatox.2018.04.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 05/26/2023]
Abstract
To better understand heavy metal tolerance in Chlamydomonas acidophila, an extremophilic green alga, we assembled its transcriptome and measured transcriptomic expression before and after Cd exposure in this and the neutrophilic model microalga Chlamydomonas reinhardtii. Genes possibly related to heavy metal tolerance and detoxification were identified and analyzed as potential key innovations that enable this species to live in an extremely acid habitat with high levels of heavy metals. In addition we provide a data set of single orthologous genes from eight green algal species as a valuable resource for comparative studies including eukaryotic extremophiles. Our results based on differential gene expression, detection of unique genes and analyses of codon usage all indicate that there are important genetic differences in C. acidophila compared to C. reinhardtii. Several efflux family proteins were identified as candidate key genes for adaptation to acid environments. This study suggests for the first time that exposure to cadmium strongly increases transposon expression in green algae, and that oil biosynthesis genes are induced in Chlamydomonas under heavy metal stress. Finally, the comparison of the transcriptomes of several acidophilic and non-acidophilic algae showed that the Chlamydomonas genus is polyphyletic and that acidophilic algae have distinctive aminoacid usage patterns.
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MESH Headings
- Actins/genetics
- Actins/metabolism
- Adaptation, Physiological/drug effects
- Cadmium/metabolism
- Cadmium/toxicity
- Carboxylic Ester Hydrolases/classification
- Carboxylic Ester Hydrolases/genetics
- Chlamydomonas/classification
- Chlamydomonas/drug effects
- Chlamydomonas/metabolism
- Dioxygenases/classification
- Dioxygenases/genetics
- Drug Tolerance/genetics
- Metals, Heavy/metabolism
- Metals, Heavy/toxicity
- Phylogeny
- Plant Proteins/classification
- Plant Proteins/genetics
- RNA, Plant/chemistry
- RNA, Plant/isolation & purification
- RNA, Plant/metabolism
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- Sequence Analysis, RNA
- Transcriptome/drug effects
- Water Pollutants, Chemical/chemistry
- Water Pollutants, Chemical/metabolism
- Water Pollutants, Chemical/toxicity
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Affiliation(s)
- Fernando Puente-Sánchez
- Systems Biology Program, Centro Nacional de Biotecnología (CNB-CSIC), Calle Darwin 3, 28049, Madrid, Spain
| | - Silvia Díaz
- Department of Physiology, Genetics and Microbiology, Complutense University of Madrid (UCM), Calle José Antonio Novais 12, 28040 Madrid, Spain
| | - Vanessa Penacho
- Bioarray, S.L. Parque Científico y Empresarial de la UMH, Edificio Quorum III, Avenida de la Universidad s/n, 03202 Elche, Alicante, Spain
| | - Angeles Aguilera
- Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir Km 4, 28850 Torrejón de Ardoz, Madrid, Spain
| | - Sanna Olsson
- INIA Forest Research Centre (INIA-CIFOR), Department Forest Ecology and Genetics, Carretera de la Coruña km 7.5, 28040 Madrid, Spain; Department Agricultural Sciences, P.O. Box 27, 00014 University of Helsinki, Finland.
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Barcytė D, Hodač L, Nedbalová L, Elster J. Chloromonas svalbardensis n. sp. with Insights into the Phylogroup Chloromonadinia (Chlorophyceae). J Eukaryot Microbiol 2018; 65:882-892. [PMID: 29752887 DOI: 10.1111/jeu.12633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/24/2018] [Accepted: 05/02/2018] [Indexed: 11/29/2022]
Abstract
The traditional green algal genus Chloromonas accommodates mesophilic, cold-tolerant and cold-adapted microorganisms. In this paper, we studied a new strain isolated from a wet hummock meadow in the High Arctic. We used morphological, ultrastructural and molecular data to assess the taxonomic position and phylogenetic relationships of the new isolate. The observed morphological features generally corresponded to the cold-tolerant Chloromonas characteristics. However, ellipsoidal or wide ellipsoidal vegetative cells, a massive parietal cup-shaped chloroplast with a number of continuously connected lobes, a thick cell wall, a prominent hemispherical papilla and the anterior position of an oblong or round eyespot distinguished the alga from all previously described Chloromonas species. Analyses of rbcL and 18S rRNA genes showed that the new strain formed an independent lineage within a clade containing mesophilic and psychrotolerant Chloromonas species. Comparisons of secondary structure models of a highly variable ITS2 rDNA marker supported a separate species identity of the new isolate. Considering the morphological and molecular differences from its relatives, a new psychrotolerant species, Chloromonas svalbardensis, is proposed. Further, our results demonstrated the paraphyletic origin of Chloromonas within Chloromonadinia with genetically, morphologically and ecologically well-defined clades. We discuss a scenario of a possible Chloromonas split and revision.
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Affiliation(s)
- Dovilė Barcytė
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 2 128 44, Prague, Czechia
| | - Ladislav Hodač
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Georg-August-University of Göttingen, Untere Karspüle 2, 37073, Göttingen, Germany
| | - Linda Nedbalová
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 2 128 44, Prague, Czechia.,Institute of Botany, The Czech Academy of Sciences, Dukelská 135, 379 82, Třeboň, Czechia
| | - Josef Elster
- Institute of Botany, The Czech Academy of Sciences, Dukelská 135, 379 82, Třeboň, Czechia.,Centre for Polar Ecology, University of South Bohemia, Na Zlaté stoce 3, 370 05, České Budějovice, Czechia
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Sausen N, Malavasi V, Melkonian M. Molecular phylogeny, systematics, and revision of the type species of Lobomonas, L. francei (Volvocales, Chlorophyta) and closely related taxa. JOURNAL OF PHYCOLOGY 2018; 54:198-214. [PMID: 29278416 DOI: 10.1111/jpy.12615] [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: 07/28/2017] [Accepted: 11/15/2017] [Indexed: 06/07/2023]
Abstract
In the present study, three new strains of the rare volvocalean green alga Lobomonas were isolated from field-collected samples, one from Sardinia (Italy) and two from Argentina, and comparatively studied. The Sardinian and one of the Argentinian strains were identified as Lobomonas francei, the type species of the genus, whereas the second Argentinian strain corresponded to L. panduriformis. Two additional nominal species of Lobomonas from culture collections (L. rostrata and L. sphaerica) were included in the analysis and shown to be morphologically and molecularly identical to the L. francei strains. The presence, number, and shapes of cell wall lobes, the diagnostic criterion of Lobomonas, were shown to be highly variable depending on the chemical composition of the culture medium used. The analyses by SEM gave evidence that the cell wall lobes in Lobomonas originate at the junctions of adjacent cell wall plates by extrusion of gelatinous material. The four L. francei strains had identical nrRNA gene sequences and differed by only one or two substitutions in the ITS1 + ITS2 sequences. In the phylogenetic analyses, L. francei and L. panduriformis were sister taxa; however, another nominal Lobomonas species (L. monstruosa) did not belong to this genus. Lobomonas, together with taxa designated as Vitreochlamys, Tetraspora, and Paulschulzia, formed a monophyletic group that in the combined analyses was sister to the "Chlamydomonas/Volvox-clade." Based on these results, Lobomonas was revised, the diagnosis of the type species emended, a lectotype and an epitype designated, and several taxa synonymized with the type species.
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Affiliation(s)
- Nicole Sausen
- Botanical Institute, Cologne Biocenter, University of Cologne, Zülpicher Str. 47 b, Cologne, 50674, Germany
| | - Veronica Malavasi
- Interdepartmental Center of Environmental Science and Engineering (CINSA), University of Cagliari, Via San Giorgio 12, 09124, Cagliari, Italy
| | - Michael Melkonian
- Botanical Institute, Cologne Biocenter, University of Cologne, Zülpicher Str. 47 b, Cologne, 50674, Germany
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Matsuzaki R, Nozaki H, Kawachi M. Taxonomic revision of Chloromonas nivalis (Volvocales, Chlorophyceae) strains, with the new description of two snow-inhabiting Chloromonas species. PLoS One 2018; 13:e0193603. [PMID: 29570718 PMCID: PMC5865719 DOI: 10.1371/journal.pone.0193603] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 02/14/2018] [Indexed: 01/01/2023] Open
Abstract
Chloromonas nivalis (Volvocales, Chlorophyceae) is considered a cosmopolitan species of a snow-inhabiting microalga because cysts morphologically identifiable as zygotes of the species are distributed worldwide. However, recent molecular data demonstrated that field-collected cysts identified as the zygotes consist of multiple species. Recently, we demonstrated that species identification of snow-inhabiting Chloromonas species is possible based on light and electron microscopy of asexual life cycles in strains and molecular phylogenetic analyses. Vegetative cells without eyespots and of inverted-teardrop shape have been reported once in North American material of C. nivalis; however, strains with such vegetative cells in snow-inhabiting species of Chloromonas have not been examined taxonomically in detail. Here, we used light and transmission electron microscopy together with molecular analyses of multiple DNA sequences to examine several C. nivalis strains. The morphological data demonstrated that one North American strain could be identified as C. nivalis, whereas three other strains should be re-classified as C. hoshawii sp. nov. and C. remiasii sp. nov. based on vegetative cell morphology, the number of zoospores within the parental cell wall during asexual reproduction, and whether cell aggregates (resulting from repeated divisions of daughter cells retained within a parental cell wall) were observed in the culture. This taxonomic treatment was supported by multigene phylogeny and comparative molecular analyses that included a rapidly evolving DNA region. Our molecular phylogenetic analyses also demonstrated that the North American strain of C. nivalis was phylogenetically separated from the Austrian and Japanese specimens previously identified as C. nivalis based on zygote morphology.
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Affiliation(s)
- Ryo Matsuzaki
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, Japan
- * E-mail:
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki, Japan
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Nakada T, Tomita M. Morphology and phylogeny of a new wall-less freshwater volvocalean flagellate, Hapalochloris nozakii gen. et sp. nov. (Volvocales, Chlorophyceae). JOURNAL OF PHYCOLOGY 2017; 53:108-117. [PMID: 27767210 DOI: 10.1111/jpy.12484] [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: 03/27/2016] [Accepted: 09/13/2016] [Indexed: 06/06/2023]
Abstract
New strains of a wall-less unicellular volvocalean flagellate were isolated from a freshwater environment in Japan. Observations of the alga, described here as Hapalochloris nozakii Nakada, gen. et sp. nov., were made using light, fluorescence, and electron microscopy. Each vegetative cell had two flagella, four contractile vacuoles, and a spirally furrowed cup-shaped chloroplast with an axial pyrenoid, and mitochondria located in the furrows. Based on the morphology, H. nozakii was distinguished from other known wall-less volvocalean flagellates. Under electron microscopy, fibrous material, instead of a cell wall and dense cortical microtubules, was observed outside and inside the cell membrane, respectively. Based on the phylogenetic analyses of 18S rRNA gene sequences, H. nozakii was found to be closely related to Asterococcus, Oogamochlamys, Rhysamphichloris, and "Dunaliella" lateralis and was separated from other known wall-less flagellate volvocaleans, indicating independent secondary loss of the cell wall in H. nozakii. In the combined 18S rRNA and chloroplast gene tree, H. nozakii was sister to Lobochlamys.
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Affiliation(s)
- Takashi Nakada
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan
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