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Takeuchi Y, Sato S, Nagasato C, Motomura T, Okuda S, Kasahara M, Takahashi F, Yoshikawa S. Sperm-specific histone H1 in highly condensed sperm nucleus of Sargassum horneri. Sci Rep 2024; 14:3387. [PMID: 38336896 PMCID: PMC10858212 DOI: 10.1038/s41598-024-53729-2] [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: 05/16/2023] [Accepted: 02/04/2024] [Indexed: 02/12/2024] Open
Abstract
Spermatogenesis is one of the most dramatic changes in cell differentiation. Remarkable chromatin condensation of the nucleus is observed in animal, plant, and algal sperm. Sperm nuclear basic proteins (SNBPs), such as protamine and sperm-specific histone, are involved in chromatin condensation of the sperm nucleus. Among brown algae, sperm of the oogamous Fucales algae have a condensed nucleus. However, the existence of sperm-specific SNBPs in Fucales algae was unclear. Here, we identified linker histone (histone H1) proteins in the sperm and analyzed changes in their gene expression pattern during spermatogenesis in Sargassum horneri. A search of transcriptomic data for histone H1 genes in showed six histone H1 genes, which we named ShH1.1a, ShH1b, ShH1.2, ShH1.3, ShH1.4, and ShH1.5. Analysis of SNBPs using SDS-PAGE and LC-MS/MS showed that sperm nuclei contain histone ShH1.2, ShH1.3, and ShH1.4 in addition to core histones. Both ShH1.2 and ShH1.3 genes were expressed in the vegetative thallus and the male and female receptacles (the organs producing antheridium or oogonium). Meanwhile, the ShH1.4 gene was expressed in the male receptacle but not in the vegetative thallus and female receptacles. From these results, ShH1.4 may be a sperm-specific histone H1 of S. horneri.
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Affiliation(s)
- Yu Takeuchi
- Faculty of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuencho, Obama, Fukui, 917-0003, Japan
| | - Shinya Sato
- Faculty of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuencho, Obama, Fukui, 917-0003, Japan
| | - Chikako Nagasato
- Field Science Center for Northern Biosphere, Muroran Marine Station, Hokkaido University, Muroran, 051-0013, Japan
| | - Taizo Motomura
- Field Science Center for Northern Biosphere, Muroran Marine Station, Hokkaido University, Muroran, 051-0013, Japan
| | - Shujiro Okuda
- Graduate School of Medical and Dental Science, Niigata University, 1-757 Asahimachi, Chuoku, Niigata, Niigata, 951-8501, Japan
| | - Masahiro Kasahara
- Graduate School of Life Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan
| | - Fumio Takahashi
- Graduate School of Life Sciences, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga, 525-8577, Japan
- Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, 274-8510, Japan
| | - Shinya Yoshikawa
- Faculty of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuencho, Obama, Fukui, 917-0003, Japan.
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2
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Barcytė D, Zátopková M, Němcová Y, Richtář M, Yurchenko T, Jaške K, Fawley KP, Škaloud P, Ševčíková T, Fawley MW, Eliáš M. Redefining Chlorobotryaceae as one of the principal and most diverse lineages of eustigmatophyte algae. Mol Phylogenet Evol 2022; 177:107607. [PMID: 35963589 DOI: 10.1016/j.ympev.2022.107607] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/11/2022] [Accepted: 08/05/2022] [Indexed: 10/15/2022]
Abstract
Eustigmatophyceae is one of the ∼17 classes of the vast algal phylum Ochrophyta. Over the last decade, the eustigmatophytes emerged as an expansive group that has grown from the initially recognized handful of species to well over 200 genetically distinct entities (potential species). Yet the majority of eustigs, remain represented by unidentified strains, or even only metabarcode sequences obtained from environmental samples. Moreover, the formal classification of the group has not yet been harmonized with the recently uncovered diversity and phylogenetic relationships within the class. Here we make a major step towards resolving this issue by addressing the diversity, phylogeny and classification of one of the most prominent eustigmatophyte clades previously informally called the "Eustigmataceae group". We obtained 18S rDNA and rbcL gene sequences from four new strains from the "Eustigmataceae group", and from several additional eustig strains, and performed the most comprehensive phylogenetic analyses of Eustigmatophyceae to date. Our results of these analyses confirm the monophyly of the "Eustigmataceae group" and define its major subclades. We also sequenced plastid genomes of five "Eustigmataceae group" strains to not only improve our understanding of the plastid gene content evolution in eustigs, but also to obtain a robustly resolved eustigmatophyte phylogeny. With this new genomic data, we have solidified the view of the "Eustigmataceae group" as a well-defined family level clade. Crucially, we also have firmly established the genus Chlorobotrys as a member of the "Eustigmataceae group". This new molecular evidence, together with a critical analysis of the literature going back to the 19th century, provided the basis to radically redefine the historical concept of the family Chlorobotryaceae as the formal taxonomic rubric corresponding to the "Eustigmataceae group". With this change, the family names Eustigmataceae and Characiopsidaceae are reduced to synonymy with the Chlorobotryaceae, with the latter having taxonomic priority. We additionally studied in detail the morphology and ultrastructure of two Chlorobotryaceae members, which we describe as Neustupella aerophytica gen. et sp. nov. and Lietzensia polymorpha gen. et sp. nov. Finally, our analyses of partial genomic data from several Chlorobotryaceae representatives identified genes for hallmark flagellar proteins in all of these strains. The presence of the flagellar proteins strongly suggests that zoosporogenesis is a common trait of the family and also occurs in the members never observed to produce flagellated stages. Altogether, our work paints a rich picture of one of the most diverse principal lineages of eustigmatophyte algae.
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Affiliation(s)
- Dovilė Barcytė
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
| | - Martina Zátopková
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Yvonne Němcová
- Department of Botany, Faculty of Science, Charles University, Benátská 2, 128 00 Prague, Czech Republic
| | - Michal Richtář
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Tatiana Yurchenko
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Karin Jaške
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Karen P Fawley
- Division of Science and Mathematics, University of the Ozarks, Clarksville, AR 72830, USA
| | - Pavel Škaloud
- Department of Botany, Faculty of Science, Charles University, Benátská 2, 128 00 Prague, Czech Republic
| | - Tereza Ševčíková
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Marvin W Fawley
- Division of Science and Mathematics, University of the Ozarks, Clarksville, AR 72830, USA
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
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Barcytė D, Eikrem W, Engesmo A, Seoane S, Wohlmann J, Horák A, Yurchenko T, Eliáš M. Olisthodiscus represents a new class of Ochrophyta. JOURNAL OF PHYCOLOGY 2021; 57:1094-1118. [PMID: 33655496 DOI: 10.1111/jpy.13155] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 12/08/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
The phylogenetic diversity of Ochrophyta, a diverse and ecologically important radiation of algae, is still incompletely understood even at the level of the principal lineages. One taxon that has eluded simple classification is the marine flagellate genus Olisthodiscus. We investigated Olisthodiscus luteus K-0444 and documented its morphological and genetic differences from the NIES-15 strain, which we described as Olisthodiscus tomasii sp. nov. Phylogenetic analyses of combined 18S and 28S rRNA sequences confirmed that Olisthodiscus constitutes a separate, deep, ochrophyte lineage, but its position could not be resolved. To overcome this problem, we sequenced the plastid genome of O. luteus K-0444 and used the new data in multigene phylogenetic analyses, which suggested that Olisthodiscus is a sister lineage of the class Pinguiophyceae within a broader clade additionally including Chrysophyceae, Synchromophyceae, and Eustigmatophyceae. Surprisingly, the Olisthodiscus plastid genome contained three genes, ycf80, cysT, and cysW, inherited from the rhodophyte ancestor of the ochrophyte plastid yet lost from all other ochrophyte groups studied so far. Combined with nuclear genes for CysA and Sbp proteins, Olisthodiscus is the only known ochrophyte possessing a plastidial sulfate transporter SulT. In addition, the finding of a cemA gene in the Olisthodiscus plastid genome and an updated phylogenetic analysis ruled out the previously proposed hypothesis invoking horizontal cemA transfer from a green algal plastid into Synurales. Altogether, Olisthodiscus clearly represents a novel phylogenetically distinct ochrophyte lineage, which we have proposed as a new class, Olisthodiscophyceae.
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Affiliation(s)
- Dovilė Barcytė
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 710 00, Ostrava, Czech Republic
| | - Wenche Eikrem
- Norwegian Institute for Water Research, Gaustadallèen 21, 0349, Oslo, Norway
- Natural history Museum, University of Oslo, P.O. Box 1172 Blindern, 0318, Oslo, Norway
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316, Oslo, Norway
| | - Anette Engesmo
- Norwegian Institute for Water Research, Gaustadallèen 21, 0349, Oslo, Norway
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316, Oslo, Norway
| | - Sergio Seoane
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), 48940, Leioa, Spain
| | - Jens Wohlmann
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316, Oslo, Norway
| | - Aleš Horák
- Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Branišovská 31, 37005, České Budějovice, Czech Republic
- Department of Molecular Biology, Faculty of Science, University of South Bohemia, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Tatiana Yurchenko
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 710 00, Ostrava, Czech Republic
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 710 00, Ostrava, Czech Republic
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Bilcke G, Van den Berge K, De Decker S, Bonneure E, Poulsen N, Bulankova P, Osuna-Cruz CM, Dickenson J, Sabbe K, Pohnert G, Vandepoele K, Mangelinckx S, Clement L, De Veylder L, Vyverman W. Mating type specific transcriptomic response to sex inducing pheromone in the pennate diatom Seminavis robusta. THE ISME JOURNAL 2021; 15:562-576. [PMID: 33028976 PMCID: PMC8027222 DOI: 10.1038/s41396-020-00797-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/10/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022]
Abstract
Sexual reproduction is a fundamental phase in the life cycle of most diatoms. Despite its role as a source of genetic variation, it is rarely reported in natural circumstances and its molecular foundations remain largely unknown. Here, we integrate independent transcriptomic datasets to prioritize genes responding to sex inducing pheromones (SIPs) in the pennate diatom Seminavis robusta. We observe marked gene expression changes associated with SIP treatment in both mating types, including an inhibition of S phase progression, chloroplast division, mitosis, and cell wall formation. Meanwhile, meiotic genes are upregulated in response to SIP, including a sexually induced diatom specific cyclin. Our data further suggest an important role for reactive oxygen species, energy metabolism, and cGMP signaling during the early stages of sexual reproduction. In addition, we identify several genes with a mating type specific response to SIP, and link their expression pattern with physiological specialization, such as the production of the attraction pheromone diproline in mating type - (MT-) and mate-searching behavior in mating type + (MT+). Combined, our results provide a model for early sexual reproduction in pennate diatoms and significantly expand the suite of target genes to detect sexual reproduction events in natural diatom populations.
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Affiliation(s)
- Gust Bilcke
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, 9000, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000, Ghent, Belgium
| | - Koen Van den Berge
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000, Ghent, Belgium
- Department of Statistics, University of California, Berkeley, Berkeley, CA, USA
| | - Sam De Decker
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, 9000, Ghent, Belgium
| | - Eli Bonneure
- SynBioC, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Nicole Poulsen
- B CUBE Center for Molecular Bioengineering, Technical University of Dresden, Tatzberg 41, 01307, Dresden, Germany
| | - Petra Bulankova
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Cristina Maria Osuna-Cruz
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052, Ghent, Belgium
| | - Jack Dickenson
- Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK
- School of Ocean and Earth Science, University of Southampton, Southampton, UK
| | - Koen Sabbe
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, 9000, Ghent, Belgium
| | - Georg Pohnert
- Bioorganic Analytics, Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Lessingstr. 8, 07743, Jena, Germany
| | - Klaas Vandepoele
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052, Ghent, Belgium
| | - Sven Mangelinckx
- SynBioC, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Lieven Clement
- Department of Applied Mathematics, Computer Science and Statistics, Ghent University, 9000, Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052, Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Wim Vyverman
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, 9000, Ghent, Belgium.
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5
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Exploring Molecular Signs of Sex in the Marine Diatom Skeletonema marinoi. Genes (Basel) 2019; 10:genes10070494. [PMID: 31261777 PMCID: PMC6678668 DOI: 10.3390/genes10070494] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 11/17/2022] Open
Abstract
Sexual reproduction plays a fundamental role in diatom life cycles. It contributes to increasing genetic diversity through meiotic recombination and also represents the phase where large-sized cells are produced to counteract the cell size reduction process that characterizes these microalgae. With the aim to identify genes linked to the sexual phase of the centric planktonic diatom Skeletonema marinoi, we carried out an RNA-seq experiment comparing the expression level of transcripts in sexualized cells with that of large cells not competent for sex. A set of genes involved in meiosis were found upregulated. Despite the fact that flagellate gametes were observed in the sample, we did not detect the expression of genes involved in the synthesis of flagella that were upregulated during sexual reproduction in another centric diatom. A comparison with the set of genes changing during the first phases of sexual reproduction of the pennate diatom Pseudo-nitzschia multistriata revealed the existence of commonalities, including the strong upregulation of genes with an unknown function that we named Sex Induced Genes (SIG). Our results further broadened the panel of genes that can be used as a marker for sexual reproduction of diatoms, crucial for the interpretation of metatranscriptomic datasets.
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Hee WY, Blackman LM, Hardham AR. Characterisation of Stramenopile-specific mastigoneme proteins in Phytophthora parasitica. PROTOPLASMA 2019; 256:521-535. [PMID: 30302550 DOI: 10.1007/s00709-018-1314-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/25/2018] [Indexed: 06/08/2023]
Abstract
Mastigonemes, tripartite tubular hairs on the anterior flagellum of Phytophthora zoospores, are instrumental for disease dissemination to new host plants. A previous study showed that PnMas2 was part of the tubular shaft of Phytophthora parasitica mastigonemes. In the current study, genes encoding two related proteins, PnMas1 and PnMas3, were identified in the genome of P. parasitica. PnMas1 interacts with PnMas2 and also occurs along the mastigoneme shaft. RNA-Seq analyses indicate that PnMas1 and PnMas2 genes have similar expression profiles both in vitro and in planta but that PnMas3 is expressed temporally prior to PnMas1 and PnMas2 during asexual development and plant infection. Immunocytochemistry and GFP-tagging document the occurrence of all three PnMas proteins within the specialised compartments of the ER during mastigoneme formation, but only PnMas1 and PnMas2 occur in mature mastigonemes on the flagellar surface. Anti-PnMas1 and anti-PnMas2 antibodies co-labelled two high-molecular-weight (~400 kDa) protein complexes in native gels but anti-PnMas3 antibodies labelled a 65 kDa protein complex. Liquid chromatography-mass spectrometry analysis identified PnMas1 and PnMas2 but not PnMas3 in flagellar extracts. These results suggest that PnMas3 associates with mastigonemes during their assembly within the ER but is not part of mature mastigonemes on the anterior flagellum. Phylogenetic analyses using homologues of Mas genes from the genomes of 28 species of Stramenopiles give evidence of three Mas sub-families, namely Mas1, Mas2 and Mas3. BLAST analyses showed that Mas genes only occur in flagellate species within the Stramenopile taxon.
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Affiliation(s)
- Wei Yih Hee
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia.
| | - Leila M Blackman
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Adrienne R Hardham
- Plant Science Division, Research School of Biology, College of Science, The Australian National University, Canberra, ACT 2601, Australia
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Sexual ancestors generated an obligate asexual and globally dispersed clone within the model diatom species Thalassiosira pseudonana. Sci Rep 2018; 8:10492. [PMID: 30002405 PMCID: PMC6043606 DOI: 10.1038/s41598-018-28630-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/26/2018] [Indexed: 12/02/2022] Open
Abstract
Sexual reproduction roots the eukaryotic tree of life, although its loss occurs across diverse taxa. Asexual reproduction and clonal lineages persist in these taxa despite theoretical arguments suggesting that individual clones should be evolutionarily short-lived due to limited phenotypic diversity. Here, we present quantitative evidence that an obligate asexual lineage emerged from a sexual population of the marine diatom Thalassiosira pseudonana and rapidly expanded throughout the world’s oceans. Whole genome comparisons identified two lineages with characteristics expected of sexually reproducing strains in Hardy-Weinberg equilibrium. A third lineage displays genomic signatures for the functional loss of sexual reproduction followed by a recent global colonization by a single ancestral genotype. Extant members of this lineage are genetically differentiated and phenotypically plastic, potentially allowing for rapid adaptation when they are challenged by natural selection. Such mechanisms may be expected to generate new clones within marginal populations of additional unicellular species, facilitating the exploration and colonization of novel environments, aided by exponential growth and ease of dispersal.
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8
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Cavalier-Smith T. Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences. PROTOPLASMA 2018; 255:297-357. [PMID: 28875267 PMCID: PMC5756292 DOI: 10.1007/s00709-017-1147-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/18/2017] [Indexed: 05/18/2023]
Abstract
In 1981 I established kingdom Chromista, distinguished from Plantae because of its more complex chloroplast-associated membrane topology and rigid tubular multipartite ciliary hairs. Plantae originated by converting a cyanobacterium to chloroplasts with Toc/Tic translocons; most evolved cell walls early, thereby losing phagotrophy. Chromists originated by enslaving a phagocytosed red alga, surrounding plastids by two extra membranes, placing them within the endomembrane system, necessitating novel protein import machineries. Early chromists retained phagotrophy, remaining naked and repeatedly reverted to heterotrophy by losing chloroplasts. Therefore, Chromista include secondary phagoheterotrophs (notably ciliates, many dinoflagellates, Opalozoa, Rhizaria, heliozoans) or walled osmotrophs (Pseudofungi, Labyrinthulea), formerly considered protozoa or fungi respectively, plus endoparasites (e.g. Sporozoa) and all chromophyte algae (other dinoflagellates, chromeroids, ochrophytes, haptophytes, cryptophytes). I discuss their origin, evolutionary diversification, and reasons for making chromists one kingdom despite highly divergent cytoskeletons and trophic modes, including improved explanations for periplastid/chloroplast protein targeting, derlin evolution, and ciliary/cytoskeletal diversification. I conjecture that transit-peptide-receptor-mediated 'endocytosis' from periplastid membranes generates periplastid vesicles that fuse with the arguably derlin-translocon-containing periplastid reticulum (putative red algal trans-Golgi network homologue; present in all chromophytes except dinoflagellates). I explain chromist origin from ancestral corticates and neokaryotes, reappraising tertiary symbiogenesis; a chromist cytoskeletal synapomorphy, a bypassing microtubule band dextral to both centrioles, favoured multiple axopodial origins. I revise chromist higher classification by transferring rhizarian subphylum Endomyxa from Cercozoa to Retaria; establishing retarian subphylum Ectoreta for Foraminifera plus Radiozoa, apicomonad subclasses, new dinozoan classes Myzodinea (grouping Colpovora gen. n., Psammosa), Endodinea, Sulcodinea, and subclass Karlodinia; and ranking heterokont Gyrista as phylum not superphylum.
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9
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Moore ER, Bullington BS, Weisberg AJ, Jiang Y, Chang J, Halsey KH. Morphological and transcriptomic evidence for ammonium induction of sexual reproduction in Thalassiosira pseudonana and other centric diatoms. PLoS One 2017; 12:e0181098. [PMID: 28686696 PMCID: PMC5501676 DOI: 10.1371/journal.pone.0181098] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/26/2017] [Indexed: 11/19/2022] Open
Abstract
The reproductive strategy of diatoms includes asexual and sexual phases, but in many species, including the model centric diatom Thalassiosira pseudonana, sexual reproduction has never been observed. Furthermore, the environmental factors that trigger sexual reproduction in diatoms are not understood. Although genome sequences of a few diatoms are available, little is known about the molecular basis for sexual reproduction. Here we show that ammonium reliably induces the key sexual morphologies, including oogonia, auxospores, and spermatogonia, in two strains of T. pseudonana, T. weissflogii, and Cyclotella cryptica. RNA sequencing revealed 1,274 genes whose expression patterns changed when T. pseudonana was induced into sexual reproduction by ammonium. Some of the induced genes are linked to meiosis or encode flagellar structures of heterokont and cryptophyte algae. The identification of ammonium as an environmental trigger suggests an unexpected link between diatom bloom dynamics and strategies for enhancing population genetic diversity.
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Affiliation(s)
- Eric R. Moore
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Briana S. Bullington
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
| | - Alexandra J. Weisberg
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Yuan Jiang
- Department of Statistics, Oregon State University, Corvallis, Oregon, United States of America
| | - Jeff Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Kimberly H. Halsey
- Department of Microbiology, Oregon State University, Corvallis, Oregon, United States of America
- * E-mail:
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10
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Lipinska AP, Van Damme EJM, De Clerck O. Molecular evolution of candidate male reproductive genes in the brown algal model Ectocarpus. BMC Evol Biol 2016; 16:5. [PMID: 26728038 PMCID: PMC4700764 DOI: 10.1186/s12862-015-0577-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 12/21/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Evolutionary studies of genes that mediate recognition between sperm and egg contribute to our understanding of reproductive isolation and speciation. Surface receptors involved in fertilization are targets of sexual selection, reinforcement, and other evolutionary forces including positive selection. This observation was made across different lineages of the eukaryotic tree from land plants to mammals, and is particularly evident in free-spawning animals. Here we use the brown algal model species Ectocarpus (Phaeophyceae) to investigate the evolution of candidate gamete recognition proteins in a distant major phylogenetic group of eukaryotes. RESULTS Male gamete specific genes were identified by comparing transcriptome data covering different stages of the Ectocarpus life cycle and screened for characteristics expected from gamete recognition receptors. Selected genes were sequenced in a representative number of strains from distant geographical locations and varying stages of reproductive isolation, to search for signatures of adaptive evolution. One of the genes (Esi0130_0068) showed evidence of selective pressure. Interestingly, that gene displayed domain similarities to the receptor for egg jelly (REJ) protein involved in sperm-egg recognition in sea urchins. CONCLUSIONS We have identified a male gamete specific gene with similarity to known gamete recognition receptors and signatures of adaptation. Altogether, this gene could contribute to gamete interaction during reproduction as well as reproductive isolation in Ectocarpus and is therefore a good candidate for further functional evaluation.
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Affiliation(s)
- Agnieszka P Lipinska
- Phycology Research Group and Center for Molecular Phylogenetics and Evolution, Ghent University, Krijgslaan 281, Building S8, 9000, Ghent, Belgium.
| | - Els J M Van Damme
- Department of Molecular Biotechnology, Laboratory of Biochemistry and Glycobiology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
| | - Olivier De Clerck
- Phycology Research Group and Center for Molecular Phylogenetics and Evolution, Ghent University, Krijgslaan 281, Building S8, 9000, Ghent, Belgium.
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11
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Patil S, Moeys S, von Dassow P, Huysman MJJ, Mapleson D, De Veylder L, Sanges R, Vyverman W, Montresor M, Ferrante MI. Identification of the meiotic toolkit in diatoms and exploration of meiosis-specific SPO11 and RAD51 homologs in the sexual species Pseudo-nitzschia multistriata and Seminavis robusta. BMC Genomics 2015; 16:930. [PMID: 26572248 PMCID: PMC4647503 DOI: 10.1186/s12864-015-1983-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 10/04/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Sexual reproduction is an obligate phase in the life cycle of most eukaryotes. Meiosis varies among organisms, which is reflected by the variability of the gene set associated to the process. Diatoms are unicellular organisms that belong to the stramenopile clade and have unique life cycles that can include a sexual phase. RESULTS The exploration of five diatom genomes and one diatom transcriptome led to the identification of 42 genes potentially involved in meiosis. While these include the majority of known meiosis-related genes, several meiosis-specific genes, including DMC1, could not be identified. Furthermore, phylogenetic analyses supported gene identification and revealed ancestral loss and recent expansion in the RAD51 family in diatoms. The two sexual species Pseudo-nitzschia multistriata and Seminavis robusta were used to explore the expression of meiosis-related genes: RAD21, SPO11-2, RAD51-A, RAD51-B and RAD51-C were upregulated during meiosis, whereas other paralogs in these families showed no differential expression patterns, suggesting that they may play a role during vegetative divisions. An almost identical toolkit is shared among Pseudo-nitzschia multiseries and Fragilariopsis cylindrus, as well as two species for which sex has not been observed, Phaeodactylum tricornutum and Thalassiosira pseudonana, suggesting that these two may retain a facultative sexual phase. CONCLUSIONS Our results reveal the conserved meiotic toolkit in six diatom species and indicate that Stramenopiles share major modifications of canonical meiosis processes ancestral to eukaryotes, with important divergences in each Kingdom.
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Affiliation(s)
- Shrikant Patil
- Stazione Zoologica Anton Dohrn, Villa Comunale 1, 80121, Naples, Italy.
| | - Sara Moeys
- Department of Biology, Protistology and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium. .,Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), 9052, Ghent, Belgium. .,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium.
| | - Peter von Dassow
- Facultad de Ciencias Biológicas, Instituto Milenio de Oceanografía, Pontificia Universidad Católica de Chile, Santiago, Chile. .,UMI 3614, Evolutionary Biology and Ecology of Algae, CNRS-UPMC Sorbonne Universités, PUCCh, UACH, Station Biologique de Roscoff, Roscoff, France.
| | - Marie J J Huysman
- Department of Biology, Protistology and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium. .,Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), 9052, Ghent, Belgium. .,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium.
| | - Daniel Mapleson
- The Genome Analysis Centre (TGAC), Norwich Research Park, Norwich, NR4 7UH, UK.
| | - Lieven De Veylder
- Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), 9052, Ghent, Belgium. .,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium.
| | - Remo Sanges
- Stazione Zoologica Anton Dohrn, Villa Comunale 1, 80121, Naples, Italy.
| | - Wim Vyverman
- Department of Biology, Protistology and Aquatic Ecology, Ghent University, 9000, Ghent, Belgium.
| | - Marina Montresor
- Stazione Zoologica Anton Dohrn, Villa Comunale 1, 80121, Naples, Italy.
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12
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Kessenich CR, Ruck EC, Schurko AM, Wickett NJ, Alverson AJ. Transcriptomic Insights into the Life History of Bolidophytes, the Sister Lineage to Diatoms. JOURNAL OF PHYCOLOGY 2014; 50:977-983. [PMID: 26988780 DOI: 10.1111/jpy.12222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 06/17/2014] [Indexed: 06/05/2023]
Abstract
Diatoms are perhaps the most diverse lineage of eukaryotic algae, with their siliceous cell wall and diplontic life history often considered to have played important roles in their extraordinary diversification. The characteristic diminution of the diatom cell wall over the course of vegetative growth provides a reliable, intrinsic trigger for sexual reproduction, establishing a direct link between the evolution of their cell-wall and life-history features. It is unclear, however, whether the diplontic life cycle of diatoms represents an ancestral or derived trait. This uncertainty is based in part on our lack of understanding of the life cycle of the sister lineage to diatoms, which includes a mix of two free-living and separately classified forms: naked biflagellate unicells in the genus Bolidomonas and silicified forms in the order Parmales. These two forms might represent different life-history stages, although directly establishing such links can be difficult. We sequenced transcriptomes for Bolidomonas and two diatoms and found that ~0.1% of the coding regions in the two diploid diatoms are heterozygous, whereas Bolidomonas is virtually devoid of heterozygous alleles, consistent with expectations for a haploid genome. These results suggest that Bolidomonas is haploid and predict that parmaleans represent the diploid phase of a haplodiplontic life cycle. These data fill an important gap in our understanding of the origin of the diplontic life history of diatoms, which may represent an evolutionarily derived, adaptive feature.
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Affiliation(s)
- Colton R Kessenich
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, 72701, USA
| | - Elizabeth C Ruck
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, 72701, USA
| | - Andrew M Schurko
- Department of Biology, Hendrix College, Conway, Arkansas, 72032, USA
| | - Norman J Wickett
- Chicago Botanic Garden, Glencoe, Illinois, 60022, USA
- Program in Biological Sciences, Northwestern University, Evanston, Illinois, 60208, USA
| | - Andrew J Alverson
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, 72701, USA
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13
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Lipinska AP, D’hondt S, Van Damme EJM, De Clerck O. Uncovering the genetic basis for early isogamete differentiation: a case study of Ectocarpus siliculosus. BMC Genomics 2013; 14:909. [PMID: 24359479 PMCID: PMC3879662 DOI: 10.1186/1471-2164-14-909] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 12/17/2013] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The phenomenon of sexual reproduction characterizes nearly all eukaryotes, with anisogamy being the most prevalent form of gamete discrimination. Since dimorphic gametes most likely descend from equal-sized specialized germ cells, identifying the genetic bases of the early functional diversification in isogametes can provide better understanding of the evolution of sexual dimorphism. However, despite the potential importance to the evolutionary biology field, no comprehensive survey of the transcriptome profiling in isomorphic gametes has been reported hitherto. RESULTS Gamete differentiation on the genomic level was investigated using Ectocarpus siliculosus, a model organism for brown algal lineage which displays an isogamous sexual reproduction cycle. Transcriptome libraries of male and female gametes were generated using Next Generation Sequencing technology (SOLiD) and analyzed to identify differentially regulated genes and pathways with potential roles in fertilization and gamete specialization. Gamete transcriptomes showed a high level of complexity with a large portion of gender specific gene expression. Our results indicate that over 4,000 of expressed genes are differentially regulated between male and female, including sequences related to cell movement, carbohydrate and lipid metabolism, signaling, transport and RNA processing. CONCLUSIONS This first comprehensive transcriptomic study of protist isogametes describes considerable adaptation to distinct sexual roles, suggesting that functional anisogamy precedes morphological differentiation. Several sex-biased genes and pathways with a putative role in reproduction were identified, providing the basis for more detailed investigations of the mechanisms underlying evolution of mating types and sexual dimorphism.
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Affiliation(s)
- Agnieszka P Lipinska
- Phycology Research Group and Center for Molecular Phylogenetics and Evolution, Ghent University, Krijgslaan 281, Building S8, 9000 Ghent, Belgium
| | - Sofie D’hondt
- Phycology Research Group and Center for Molecular Phylogenetics and Evolution, Ghent University, Krijgslaan 281, Building S8, 9000 Ghent, Belgium
| | - Els JM Van Damme
- Department of Molecular Biotechnology, Laboratory of Biochemistry and Glycobiology, Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Olivier De Clerck
- Phycology Research Group and Center for Molecular Phylogenetics and Evolution, Ghent University, Krijgslaan 281, Building S8, 9000 Ghent, Belgium
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14
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Matsunaga S, Uchida H, Iseki M, Watanabe M, Murakami A. Flagellar motions in phototactic steering in a brown algal swarmer. Photochem Photobiol 2010; 86:374-81. [PMID: 20003172 DOI: 10.1111/j.1751-1097.2009.00676.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using infrared high-speed video microscopy, we observed light-triggered transitory flagellar motions in flagellate reproductive cells (swarmers) of a brown alga, Scytosiphon lomentaria, under primary helical swimming conditions before and during negative phototactic orientation to unilateral actinic light. The posterior flagellum, which is autofluorescent and thought to be light-sensing, was passively dragged in the dark and exhibited one to several rapid lateral beats during orientation changes for phototactic steering. Notably, a brief cessation of anterior flagellar beating was occasionally observed concomitantly with rapid beats of the posterior flagellum. This behavior caused a pause in helical body rotation, which may contribute to the accuracy of phototactic steering. Thus, coordinated regulation of the movement of the two flagella plays a crucial role in phototactic steering.
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Affiliation(s)
- Shigeru Matsunaga
- Hayama Center for Advanced Studies, Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
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15
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Yamagishi T, Motomura T, Nagasato C, Kawai H. NOVEL PROTEINS COMPRISING THE STRAMENOPILE TRIPARTITE MASTIGONEME IN OCHROMONAS DANICA (CHRYSOPHYCEAE)(1). JOURNAL OF PHYCOLOGY 2009; 45:1110-1115. [PMID: 27032356 DOI: 10.1111/j.1529-8817.2009.00722.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Two-dimensional (2-D) protein analysis of the mastigoneme fraction of the chromophyte alga Ochromonas danica E. G. Pringsh. showed the presence of several component proteins of the tubular mastigoneme. Adding to the reported gene Ocm1, three new genes (Ocm2, Ocm3, and Ocm4) belonging to the Ocm gene family were isolated using degenerate primers designed from predicted Ocm1 amino acid sequences. The predicted polypeptides encoded by Ocm2, Ocm3, and Ocm4 were smaller in size than Ocm1. However, they shared four highly conserved, cysteine-rich, epithelial growth factor (EGF)-like motifs, potentially involved in protein-protein interaction. In addition, Ocm2, Ocm3, and Ocm4 showed homology to the SIG protein family in the centric diatom Thalassiosira weissflogii (Grunow) Fryxell et Hasle, which is up-regulated during early stages of sexual reproduction. Immunofluorescence analysis with a polyclonal antibody against the partial amino acid sequences of Ocm2, Ocm3, and Ocm4 showed that Ocm2 and Ocm3 were located in the basal segment region of mastigonemes attached on the surface of the anterior flagellum, and that Ocm4 was located within the tubular shaft portion similar to Ocm1.
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Affiliation(s)
- Takahiro Yamagishi
- Research Center for Inland Seas, Kobe University, Kobe 657-8501, JapanMuroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0003, JapanResearch Center for Inland Seas, Kobe University, Kobe 657-8501, Japan
| | - Taizo Motomura
- Research Center for Inland Seas, Kobe University, Kobe 657-8501, JapanMuroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0003, JapanResearch Center for Inland Seas, Kobe University, Kobe 657-8501, Japan
| | - Chikako Nagasato
- Research Center for Inland Seas, Kobe University, Kobe 657-8501, JapanMuroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0003, JapanResearch Center for Inland Seas, Kobe University, Kobe 657-8501, Japan
| | - Hiroshi Kawai
- Research Center for Inland Seas, Kobe University, Kobe 657-8501, JapanMuroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran 051-0003, JapanResearch Center for Inland Seas, Kobe University, Kobe 657-8501, Japan
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16
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Chepurnov VA, Mann DG, von Dassow P, Vanormelingen P, Gillard J, Inzé D, Sabbe K, Vyverman W. In search of new tractable diatoms for experimental biology. Bioessays 2008; 30:692-702. [PMID: 18536039 DOI: 10.1002/bies.20773] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diatoms are a species-rich group of photosynthetic eukaryotes, with enormous ecological significance and great potential for biotechnology. During the last decade, diatoms have begun to be studied intensively using modern molecular techniques and the genomes of four diatoms have been wholly or partially sequenced. Although new insights into the biology and evolution of diatoms are accumulating rapidly due to the availability of reverse genetic tools, the full potential of these molecular biological approaches can only be fully realized if experimental control of sexual crosses becomes firmly established and widely accessible to experimental biologists. Here we discuss the issue of choosing new models for diatom research, by taking into account the broader context of diatom mating systems and the place of sex in relation to the intricate cycle of cell size reduction and restitution that is characteristic of most diatoms. We illustrate the results of our efforts to select and develop experimental systems in diatoms, using species with typical life cycle attributes, which could be used as future model organisms to complement existing ones.
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