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Pánek T, Barcytė D, Treitli SC, Záhonová K, Sokol M, Ševčíková T, Zadrobílková E, Jaške K, Yubuki N, Čepička I, Eliáš M. A new lineage of non-photosynthetic green algae with extreme organellar genomes. BMC Biol 2022; 20:66. [PMID: 35296310 PMCID: PMC8928634 DOI: 10.1186/s12915-022-01263-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/22/2022] [Indexed: 12/27/2022] Open
Abstract
Background The plastid genomes of the green algal order Chlamydomonadales tend to expand their non-coding regions, but this phenomenon is poorly understood. Here we shed new light on organellar genome evolution in Chlamydomonadales by studying a previously unknown non-photosynthetic lineage. We established cultures of two new Polytoma-like flagellates, defined their basic characteristics and phylogenetic position, and obtained complete organellar genome sequences and a transcriptome assembly for one of them. Results We discovered a novel deeply diverged chlamydomonadalean lineage that has no close photosynthetic relatives and represents an independent case of photosynthesis loss. To accommodate these organisms, we establish the new genus Leontynka, with two species (L. pallida and L. elongata) distinguishable through both their morphological and molecular characteristics. Notable features of the colourless plastid of L. pallida deduced from the plastid genome (plastome) sequence and transcriptome assembly include the retention of ATP synthase, thylakoid-associated proteins, the carotenoid biosynthesis pathway, and a plastoquinone-based electron transport chain, the latter two modules having an obvious functional link to the eyespot present in Leontynka. Most strikingly, the ~362 kbp plastome of L. pallida is by far the largest among the non-photosynthetic eukaryotes investigated to date due to an extreme proliferation of sequence repeats. These repeats are also present in coding sequences, with one repeat type found in the exons of 11 out of 34 protein-coding genes, with up to 36 copies per gene, thus affecting the encoded proteins. The mitochondrial genome of L. pallida is likewise exceptionally large, with its >104 kbp surpassed only by the mitogenome of Haematococcus lacustris among all members of Chlamydomonadales hitherto studied. It is also bloated with repeats, though entirely different from those in the L. pallida plastome, which contrasts with the situation in H. lacustris where both the organellar genomes have accumulated related repeats. Furthermore, the L. pallida mitogenome exhibits an extremely high GC content in both coding and non-coding regions and, strikingly, a high number of predicted G-quadruplexes. Conclusions With its unprecedented combination of plastid and mitochondrial genome characteristics, Leontynka pushes the frontiers of organellar genome diversity and is an interesting model for studying organellar genome evolution. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01263-w.
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Affiliation(s)
- Tomáš Pánek
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic.,Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic
| | - Dovilė Barcytė
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic
| | - Sebastian C Treitli
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, 252 42, Vestec, Czech Republic
| | - Kristína Záhonová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic
| | - Martin Sokol
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic
| | - Tereza Ševčíková
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic
| | - Eliška Zadrobílková
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic
| | - Karin Jaške
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic
| | - Naoji Yubuki
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic.,Bioimaging Facility, University of British Columbia, Vancouver, V6T 1Z4, Canada
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, 128 43, Prague, Czech Republic
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, 701 00, Ostrava, Czech Republic.
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Waltz F, Salinas-Giegé T, Englmeier R, Meichel H, Soufari H, Kuhn L, Pfeffer S, Förster F, Engel BD, Giegé P, Drouard L, Hashem Y. How to build a ribosome from RNA fragments in Chlamydomonas mitochondria. Nat Commun 2021; 12:7176. [PMID: 34887394 PMCID: PMC8660880 DOI: 10.1038/s41467-021-27200-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/08/2021] [Indexed: 01/12/2023] Open
Abstract
Mitochondria are the powerhouse of eukaryotic cells. They possess their own gene expression machineries where highly divergent and specialized ribosomes, named hereafter mitoribosomes, translate the few essential messenger RNAs still encoded by mitochondrial genomes. Here, we present a biochemical and structural characterization of the mitoribosome in the model green alga Chlamydomonas reinhardtii, as well as a functional study of some of its specific components. Single particle cryo-electron microscopy resolves how the Chlamydomonas mitoribosome is assembled from 13 rRNA fragments encoded by separate non-contiguous gene pieces. Additional proteins, mainly OPR, PPR and mTERF helical repeat proteins, are found in Chlamydomonas mitoribosome, revealing the structure of an OPR protein in complex with its RNA binding partner. Targeted amiRNA silencing indicates that these ribosomal proteins are required for mitoribosome integrity. Finally, we use cryo-electron tomography to show that Chlamydomonas mitoribosomes are attached to the inner mitochondrial membrane via two contact points mediated by Chlamydomonas-specific proteins. Our study expands our understanding of mitoribosome diversity and the various strategies these specialized molecular machines adopt for membrane tethering.
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Affiliation(s)
- Florent Waltz
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Thalia Salinas-Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
| | - Robert Englmeier
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Herrade Meichel
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France
| | - Heddy Soufari
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France
| | - Lauriane Kuhn
- Plateforme protéomique Strasbourg Esplanade FRC1589 du CNRS, Université de Strasbourg, 67084, Strasbourg, France
| | - Stefan Pfeffer
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany
| | - Friedrich Förster
- Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Benjamin D Engel
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Philippe Giegé
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France.
| | - Laurence Drouard
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du général Zimmer, 67084, Strasbourg, France.
| | - Yaser Hashem
- Institut Européen de Chimie et Biologie, U1212 Inserm, Université de Bordeaux, 2 rue R. Escarpit, 33600, Pessac, France.
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3
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Chen L, Ren W, Zhang B, Chen W, Fang Z, Yang L, Zhuang M, Lv H, Wang Y, Ji J, Zhang Y. Organelle Comparative Genome Analysis Reveals Novel Alloplasmic Male Sterility with orf112 in Brassica oleracea L. Int J Mol Sci 2021; 22:ijms222413230. [PMID: 34948024 PMCID: PMC8703919 DOI: 10.3390/ijms222413230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 11/16/2022] Open
Abstract
B. oleracea Ogura CMS is an alloplasmic male-sterile line introduced from radish by interspecific hybridization and protoplast fusion. The introduction of alien cytoplasm resulted in many undesirable traits, which affected the yield of hybrids. Therefore, it is necessary to identify the composition and reduce the content of alien cytoplasm in B. oleracea Ogura CMS. In the present study, we sequenced, assembled, and compared the organelle genomes of Ogura CMS cabbage and its maintainer line. The chloroplast genome of Ogura-type cabbage was completely derived from normal-type cabbage, whereas the mitochondrial genome was recombined from normal-type cabbage and Ogura-type radish. Nine unique regions derived from radish were identified in the mitochondrial genome of Ogura-type cabbage, and the total length of these nine regions was 35,618 bp, accounting for 13.84% of the mitochondrial genome. Using 32 alloplasmic markers designed according to the sequences of these nine regions, one novel sterile source with less alien cytoplasm was discovered among 305 materials and named Bel CMS. The size of the alien cytoplasm in Bel CMS was 21,587 bp, accounting for 8.93% of its mtDNA, which was much less than that in Ogura CMS. Most importantly, the sterility gene orf138 was replaced by orf112, which had a 78-bp deletion, in Bel CMS. Interestingly, Bel CMS cabbage also maintained 100% sterility, although orf112 had 26 fewer amino acids than orf138. Field phenotypic observation showed that Bel CMS was an excellent sterile source with stable 100% sterility and no withered buds at the early flowering stage, which could replace Ogura CMS in cabbage heterosis utilization.
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Affiliation(s)
- Li Chen
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenjing Ren
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Bin Zhang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Wendi Chen
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Zhiyuan Fang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Limei Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Mu Zhuang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Honghao Lv
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Yong Wang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Jialei Ji
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
| | - Yangyong Zhang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Ministry of Agriculture, Beijing 100081, China; (L.C.); (W.R.); (B.Z.); (W.C.); (Z.F.); (L.Y.); (M.Z.); (H.L.); (Y.W.); (J.J.)
- Correspondence:
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4
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Mitochondrial Genomic Landscape: A Portrait of the Mitochondrial Genome 40 Years after the First Complete Sequence. Life (Basel) 2021; 11:life11070663. [PMID: 34357035 PMCID: PMC8303319 DOI: 10.3390/life11070663] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 12/11/2022] Open
Abstract
Notwithstanding the initial claims of general conservation, mitochondrial genomes are a largely heterogeneous set of organellar chromosomes which displays a bewildering diversity in terms of structure, architecture, gene content, and functionality. The mitochondrial genome is typically described as a single chromosome, yet many examples of multipartite genomes have been found (for example, among sponges and diplonemeans); the mitochondrial genome is typically depicted as circular, yet many linear genomes are known (for example, among jellyfish, alveolates, and apicomplexans); the chromosome is normally said to be “small”, yet there is a huge variation between the smallest and the largest known genomes (found, for example, in ctenophores and vascular plants, respectively); even the gene content is highly unconserved, ranging from the 13 oxidative phosphorylation-related enzymatic subunits encoded by animal mitochondria to the wider set of mitochondrial genes found in jakobids. In the present paper, we compile and describe a large database of 27,873 mitochondrial genomes currently available in GenBank, encompassing the whole eukaryotic domain. We discuss the major features of mitochondrial molecular diversity, with special reference to nucleotide composition and compositional biases; moreover, the database is made publicly available for future analyses on the MoZoo Lab GitHub page.
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5
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Smith DR, Craig RJ. Does mitochondrial DNA replication in Chlamydomonas require a reverse transcriptase? THE NEW PHYTOLOGIST 2021; 229:1192-1195. [PMID: 32936939 DOI: 10.1111/nph.16930] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Affiliation(s)
- David Roy Smith
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Rory J Craig
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
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6
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Fuentes-Ramírez EO, Vázquez-Acevedo M, Cabrera-Orefice A, Guerrero-Castillo S, González-Halphen D. The plastid proteome of the nonphotosynthetic chlorophycean alga Polytomella parva. Microbiol Res 2020; 243:126649. [PMID: 33285428 DOI: 10.1016/j.micres.2020.126649] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/23/2020] [Accepted: 11/13/2020] [Indexed: 11/19/2022]
Abstract
The unicellular, free-living, nonphotosynthetic chlorophycean alga Polytomella parva, closely related to Chlamydomonas reinhardtii and Volvox carteri, contains colorless, starch-storing plastids. The P. parva plastids lack all light-dependent processes but maintain crucial metabolic pathways. The colorless alga also lacks a plastid genome, meaning no transcription or translation should occur inside the organelle. Here, using an algal fraction enriched in plastids as well as publicly available transcriptome data, we provide a morphological and proteomic characterization of the P. parva plastid, ultimately identifying several plastid proteins, both by mass spectrometry and bioinformatic analyses. Data are available via ProteomeXchange with identifier PXD022051. Altogether these results led us to propose a plastid proteome for P. parva, i.e., a set of proteins that participate in carbohydrate metabolism; in the synthesis and degradation of starch, amino acids and lipids; in the biosynthesis of terpenoids and tetrapyrroles; in solute transport and protein translocation; and in redox homeostasis. This is the first detailed plastid proteome from a unicellular, free-living colorless alga.
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Affiliation(s)
- Emma O Fuentes-Ramírez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
| | - Miriam Vázquez-Acevedo
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
| | - Alfredo Cabrera-Orefice
- Radboud Institute for Molecular Life Sciences, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525, GA, Nijmegen, the Netherlands.
| | - Sergio Guerrero-Castillo
- Radboud Institute for Molecular Life Sciences, Department of Pediatrics, Radboud University Medical Center, Geert Grooteplein-Zuid 10, 6525, GA, Nijmegen, the Netherlands; University Children's Research@Kinder-UKE, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, CDMX, Mexico.
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7
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Thairu MW, Hansen AK. It's a small, small world: unravelling the role and evolution of small RNAs in organelle and endosymbiont genomes. FEMS Microbiol Lett 2019; 366:5371121. [PMID: 30844054 DOI: 10.1093/femsle/fnz049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 03/05/2019] [Indexed: 12/19/2022] Open
Abstract
Organelles and host-restricted bacterial symbionts are characterized by having highly reduced genomes that lack many key regulatory genes and elements. Thus, it has been hypothesized that the eukaryotic nuclear genome is primarily responsible for regulating these symbioses. However, with the discovery of organelle- and symbiont-expressed small RNAs (sRNAs) there is emerging evidence that these sRNAs may play a role in gene regulation as well. Here, we compare the diversity of organelle and bacterial symbiont sRNAs recently identified using genome-enabled '-omic' technologies and discuss their potential role in gene regulation. We also discuss how the genome architecture of small genomes may influence the evolution of these sRNAs and their potential function. Additionally, these new studies suggest that some sRNAs are conserved within organelle and symbiont taxa and respond to changes in the environment and/or their hosts. In summary, these results suggest that organelle and symbiont sRNAs may play a role in gene regulation in addition to nuclear-encoded host mechanisms.
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Affiliation(s)
- Margaret W Thairu
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| | - Allison K Hansen
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
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8
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Valach M, Moreira S, Hoffmann S, Stadler PF, Burger G. Keeping it complicated: Mitochondrial genome plasticity across diplonemids. Sci Rep 2017; 7:14166. [PMID: 29074957 PMCID: PMC5658414 DOI: 10.1038/s41598-017-14286-z] [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: 06/30/2017] [Accepted: 10/06/2017] [Indexed: 01/30/2023] Open
Abstract
Chromosome rearrangements are important drivers in genome and gene evolution, with implications ranging from speciation to development to disease. In the flagellate Diplonema papillatum (Euglenozoa), mitochondrial genome rearrangements have resulted in nearly hundred chromosomes and a systematic dispersal of gene fragments across the multipartite genome. Maturation into functional RNAs involves separate transcription of gene pieces, joining of precursor RNAs via trans-splicing, and RNA editing by substitution and uridine additions both reconstituting crucial coding sequence. How widespread these unusual features are across diplonemids is unclear. We have analyzed the mitochondrial genomes and transcriptomes of four species from the Diplonema/Rhynchopus clade, revealing a considerable genomic plasticity. Although gene breakpoints, and thus the total number of gene pieces (~80), are essentially conserved across this group, the number of distinct chromosomes varies by a factor of two, with certain chromosomes combining up to eight unrelated gene fragments. Several internal protein-coding gene pieces overlap substantially, resulting, for example, in a stretch of 22 identical amino acids in cytochrome c oxidase subunit 1 and NADH dehydrogenase subunit 5. Finally, the variation of post-transcriptional editing patterns across diplonemids indicates compensation of two adverse trends: rapid sequence evolution and loss of genetic information through unequal chromosome segregation.
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Affiliation(s)
- Matus Valach
- Department of biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, 2900 Edouard-Montpetit, Montreal, H3T 1J4, QC, Canada.
| | - Sandrine Moreira
- Department of biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, 2900 Edouard-Montpetit, Montreal, H3T 1J4, QC, Canada.,Department of Biochemistry and Molecular Biophysics, Columbia University, Hammer Health Science Center, 701 W 168th St, New York, NY, 10031, USA
| | - Steve Hoffmann
- Leipzig University, LIFE - Leipzig Research Center for Civilization Diseases, Haertelstrasse 16-18, Leipzig, D-04107, Germany
| | - Peter F Stadler
- Bioinformatics Group, Department Computer Science, and Interdisciplinary Center for Bioinformatics, University Leipzig, Härtelstrasse 16-18, D-04107, Leipzig, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Competence Center for Scalable Data Services and Solutions, and Leipzig Research Center for Civilization Diseases, University Leipzig, D-04107, Leipzig, Germany.,Max Planck Institute for Mathematics in the Sciences, Inselstrasse 22, D-04103, Leipzig, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Perlickstrasse 1, D-04103, Leipzig, Germany.,Department of Theoretical Chemistry of the University of Vienna, Währingerstrasse 17, A-1090, Vienna, Austria.,Center for RNA in Technology and Health, University of Copenhagen, Grønnegårdsvej 3, 1870, Frederiksberg C, Denmark.,Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM, 87501, USA
| | - Gertraud Burger
- Department of biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, 2900 Edouard-Montpetit, Montreal, H3T 1J4, QC, Canada.
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9
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Reductive evolution of chloroplasts in non-photosynthetic plants, algae and protists. Curr Genet 2017; 64:365-387. [DOI: 10.1007/s00294-017-0761-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/22/2017] [Accepted: 10/04/2017] [Indexed: 11/24/2022]
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10
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Yurina NP, Odintsova MS. Mitochondrial Genome Structure of Photosynthetic Eukaryotes. BIOCHEMISTRY (MOSCOW) 2017; 81:101-13. [PMID: 27260390 DOI: 10.1134/s0006297916020048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Current ideas of plant mitochondrial genome organization are presented. Data on the size and structural organization of mtDNA, gene content, and peculiarities are summarized. Special emphasis is given to characteristic features of the mitochondrial genomes of land plants and photosynthetic algae that distinguish them from the mitochondrial genomes of other eukaryotes. The data published before the end of 2014 are reviewed.
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Affiliation(s)
- N P Yurina
- Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
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11
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Watanabe S, Fučíková K, Lewis LA, Lewis PO. Hiding in plain sight: Koshicola spirodelophila gen. et sp. nov. (Chaetopeltidales, Chlorophyceae), a novel green alga associated with the aquatic angiosperm Spirodela polyrhiza. AMERICAN JOURNAL OF BOTANY 2016; 103:865-75. [PMID: 27208355 DOI: 10.3732/ajb.1500481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/04/2016] [Indexed: 05/25/2023]
Abstract
PREMISE OF THE STUDY Discovery and morphological characterization of a novel epiphytic aquatic green alga increases our understanding of Chaetopeltidales, a poorly known order in Chlorophyceae. Chloroplast genomic data from this taxon reveals an unusual architecture previously unknown in green algae. METHODS Using light and electron microscopy, we characterized the morphology and ultrastructure of a novel taxon of green algae. Bayesian phylogenetic analyses of nuclear and plastid genes were used to test the hypothesized membership of this taxon in order Chaetopeltidales. With next-generation sequence data, we assembled the plastid genome of this novel taxon and compared its gene content and architecture to that of related species to further investigate plastid genome traits. KEY RESULTS The morphology and ultrastructure of this alga are consistent with placement in Chaetopeltidales (Chlorophyceae), but a distinct trait combination supports recognition of this alga as a new genus and species-Koshicola spirodelophila gen. et sp. nov. Its placement in the phylogeny as a descendant of a deep division in the Chaetopeltidales is supported by analysis of molecular data sets. The chloroplast genome is among the largest reported in green algae and the genes are distributed on three large (rather than a single) chromosome, in contrast to other studied green algae. CONCLUSIONS The discovery of Koshicola spirodelophila gen. et sp. nov. highlights the importance of investigating even commonplace habitats to explore new microalgal diversity. This work expands our understanding of the morphological and chloroplast genomic features of green algae, and in particular those of the poorly studied Chaetopeltidales.
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Affiliation(s)
- Shin Watanabe
- Department of Biology, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | - Karolina Fučíková
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Storrs, Connecticut 06269 USA
| | - Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Storrs, Connecticut 06269 USA
| | - Paul O Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Storrs, Connecticut 06269 USA
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12
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Tian Y, Smith DR. Recovering complete mitochondrial genome sequences from RNA-Seq: A case study of Polytomella non-photosynthetic green algae. Mol Phylogenet Evol 2016; 98:57-62. [DOI: 10.1016/j.ympev.2016.01.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 01/28/2016] [Indexed: 10/22/2022]
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13
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Vázquez-Acevedo M, Vega-deLuna F, Sánchez-Vásquez L, Colina-Tenorio L, Remacle C, Cardol P, Miranda-Astudillo H, González-Halphen D. Dissecting the peripheral stalk of the mitochondrial ATP synthase of chlorophycean algae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1183-1190. [PMID: 26873638 DOI: 10.1016/j.bbabio.2016.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/25/2016] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
The algae Chlamydomonas reinhardtii and Polytomella sp., a green and a colorless member of the chlorophycean lineage respectively, exhibit a highly-stable dimeric mitochondrial F1Fo-ATP synthase (complex V), with a molecular mass of 1600 kDa. Polytomella, lacking both chloroplasts and a cell wall, has greatly facilitated the purification of the algal ATP-synthase. Each monomer of the enzyme has 17 polypeptides, eight of which are the conserved, main functional components, and nine polypeptides (Asa1 to Asa9) unique to chlorophycean algae. These atypical subunits form the two robust peripheral stalks observed in the highly-stable dimer of the algal ATP synthase in several electron-microscopy studies. The topological disposition of the components of the enzyme has been addressed with cross-linking experiments in the isolated complex; generation of subcomplexes by limited dissociation of complex V; detection of subunit-subunit interactions using recombinant subunits; in vitro reconstitution of subcomplexes; silencing of the expression of Asa subunits; and modeling of the overall structural features of the complex by EM image reconstruction. Here, we report that the amphipathic polymer Amphipol A8-35 partially dissociates the enzyme, giving rise to two discrete dimeric subcomplexes, whose compositions were characterized. An updated model for the topological disposition of the 17 polypeptides that constitute the algal enzyme is suggested. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Miriam Vázquez-Acevedo
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Félix Vega-deLuna
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lorenzo Sánchez-Vásquez
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Lilia Colina-Tenorio
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico
| | - Claire Remacle
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Pierre Cardol
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, Department of Life Sciences, University of Liège, B-4000 Liège, Belgium
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México D.F., Mexico.
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14
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Zhou L, Wang L, Zhang J, Cai C, He P. Complete mitochondrial genome of Ulva prolifera, the dominant species of green macroalgal blooms in Yellow Sea, China. MITOCHONDRIAL DNA PART B-RESOURCES 2016; 1:76-78. [PMID: 33473415 PMCID: PMC7799800 DOI: 10.1080/23802359.2015.1137831] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Ulva prolifera (U. prolifera), a green macroalgae, is widely known as the dominant species of the world's largest macroalgal blooms in the Yellow Sea, China. In this study, we sequenced and annotated the complete mitochondrial genome of U. prolifera (GenBank accession number: KU161104). The genome consists of circular chromosomes of 61 962 bp and encodes a total of 26 protein-coding genes include nine ribosomal protein genes, five atp genes, three cox genes, eight nad genes and cob gene. Phylogenetic analysis showed U. prolifera clustered into Ulvo phyceae clade and had close genetic relationship with algae Ulva fasciata.
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Affiliation(s)
- Lingjie Zhou
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, P. R. China
| | - Lingke Wang
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, P. R. China
| | - Jianheng Zhang
- College of Marine Sciences, Shanghai Ocean University, Shanghai, P. R. China
| | - Chuner Cai
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, P. R. China
| | - Peimin He
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, P. R. China
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15
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Zhou L, Wang L, Zhang J, Cai C, He P. Complete mitochondrial genome of Ulva linza, one of the causal species of green macroalgal blooms in Yellow Sea, China. MITOCHONDRIAL DNA PART B-RESOURCES 2016; 1:31-33. [PMID: 33473396 PMCID: PMC7799859 DOI: 10.1080/23802359.2015.1137806] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Ulva linza, a green macroalgae, is one of the causal species of the world's largest macroalgal blooms in the Yellow Sea, China. In this study, we sequenced and annotated the complete mitochondrial genome of U.linza (GenBank accession no. KU189740). The genome consists of circular chromosomes of 70 858 bp and encodes a total of 28 protein-coding genes including eight rps genes, three rpl genes, five atp genes, three cox genes, eight nad genes and cob gene. Phylogenetic analysis showed U. linza clustered into Ulvophyceae clade and had close genetic relationship with algae Ulva prolifera.
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Affiliation(s)
- Lingjie Zhou
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, PR China
| | - Lingke Wang
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, PR China
| | - Jianheng Zhang
- College of Marine Sciences, Shanghai Ocean University, Shanghai, PR China
| | - Chuner Cai
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, PR China
| | - Peimin He
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, PR China
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16
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MacDonald SM, Lee RW. Validation of Polytomella piriformis
nomen nudum (Chlamydomonadaceae): a Distinct Lineage Within a Genus of Nonphotosynthetic Green Algae. J Eukaryot Microbiol 2015; 62:840-4. [DOI: 10.1111/jeu.12241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/28/2015] [Accepted: 05/29/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Shelley M. MacDonald
- Department of Biology; Dalhousie University; 1355 Oxford St. Halifax Nova Scotia B3H 4R2 Canada
| | - Robert W. Lee
- Department of Biology; Dalhousie University; 1355 Oxford St. Halifax Nova Scotia B3H 4R2 Canada
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17
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Mitochondrial and plastid genome architecture: Reoccurring themes, but significant differences at the extremes. Proc Natl Acad Sci U S A 2015; 112:10177-84. [PMID: 25814499 DOI: 10.1073/pnas.1422049112] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial and plastid genomes show a wide array of architectures, varying immensely in size, structure, and content. Some organelle DNAs have even developed elaborate eccentricities, such as scrambled coding regions, nonstandard genetic codes, and convoluted modes of posttranscriptional modification and editing. Here, we compare and contrast the breadth of genomic complexity between mitochondrial and plastid chromosomes. Both organelle genomes have independently evolved many of the same features and taken on similar genomic embellishments, often within the same species or lineage. This trend is most likely because the nuclear-encoded proteins mediating these processes eventually leak from one organelle into the other, leading to a high likelihood of processes appearing in both compartments in parallel. However, the complexity and intensity of genomic embellishments are consistently more pronounced for mitochondria than for plastids, even when they are found in both compartments. We explore the evolutionary forces responsible for these patterns and argue that organelle DNA repair processes, mutation rates, and population genetic landscapes are all important factors leading to the observed convergence and divergence in organelle genome architecture.
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18
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Del Vasto M, Figueroa-Martinez F, Featherston J, González MA, Reyes-Prieto A, Durand PM, Smith DR. Massive and widespread organelle genomic expansion in the green algal genus Dunaliella. Genome Biol Evol 2015; 7:656-63. [PMID: 25663488 PMCID: PMC5322560 DOI: 10.1093/gbe/evv027] [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] [Indexed: 12/21/2022] Open
Abstract
The mitochondrial genomes of chlamydomonadalean green algae are renowned for their highly reduced and conserved gene repertoires, which are almost fixed at 12 genes across the entire lineage. The sizes of these genomes, however, are much more variable, with some species having small, compact mitochondrial DNAs (mtDNAs) and others having expanded ones. Earlier work demonstrated that the halophilic genus Dunaliella contains extremely inflated organelle genomes, but to date the mtDNA of only one isolate has been explored. Here, by surveying mtDNA architecture across the Chlamydomonadales, we show that various Dunaliella species have undergone massive levels of mitochondrial genomic expansion, harboring the most inflated, intron-dense mtDNAs available from chlorophyte green algae. The same also appears to be true for their plastid genomes, which are potentially among the largest of all plastid-containing eukaryotes. Genetic divergence data are used to investigate the underlying causes of such extreme organelle genomic architectures, and ultimately reveal order-of-magnitude differences in mitochondrial versus plastid mutation rates within Dunaliella.
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Affiliation(s)
- Michael Del Vasto
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Francisco Figueroa-Martinez
- Department of Biology, Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jonathan Featherston
- Department of Molecular Medicine and Sydney Brenner Institute for Molecular Biosciences, University of the Witwatersrand, Johannesburg, South Africa Agricultural Research Council, Biotechnology Platform, Pretoria, South Africa
| | - Mariela A González
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanógraficas. Universidad de Concepción, Casilla, Concepción, Chile
| | - Adrian Reyes-Prieto
- Department of Biology, Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Pierre M Durand
- Department of Molecular Medicine and Sydney Brenner Institute for Molecular Biosciences, University of the Witwatersrand, Johannesburg, South Africa Department of Biodiversity and Conservation Biology, Faculty of Natural Sciences, University of the Western Cape, Belville, Cape Town, South Africa
| | - David Roy Smith
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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19
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Smith DR, Asmail SR. Next-generation sequencing data suggest that certain nonphotosynthetic green plants have lost their plastid genomes. THE NEW PHYTOLOGIST 2014; 204:7-11. [PMID: 24962290 DOI: 10.1111/nph.12919] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- David Roy Smith
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Sara Raad Asmail
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
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20
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Fučíková K, Lewis PO, González-Halphen D, Lewis LA. Gene arrangement convergence, diverse intron content, and genetic code modifications in mitochondrial genomes of sphaeropleales (chlorophyta). Genome Biol Evol 2014; 6:2170-80. [PMID: 25106621 PMCID: PMC4159012 DOI: 10.1093/gbe/evu172] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The majority of our knowledge about mitochondrial genomes of Viridiplantae comes from land plants, but much less is known about their green algal relatives. In the green algal order Sphaeropleales (Chlorophyta), only one representative mitochondrial genome is currently available—that of Acutodesmus obliquus. Our study adds nine completely sequenced and three partially sequenced mitochondrial genomes spanning the phylogenetic diversity of Sphaeropleales. We show not only a size range of 25–53 kb and variation in intron content (0–11) and gene order but also conservation of 13 core respiratory genes and fragmented ribosomal RNA genes. We also report an unusual case of gene arrangement convergence in Neochloris aquatica, where the two rns fragments were secondarily placed in close proximity. Finally, we report the unprecedented usage of UCG as stop codon in Pseudomuriella schumacherensis. In addition, phylogenetic analyses of the mitochondrial protein-coding genes yield a fully resolved, well-supported phylogeny, showing promise for addressing systematic challenges in green algae.
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Affiliation(s)
- Karolina Fučíková
- Department of Ecology and Evolutionary Biology, University of Connecticut
| | - Paul O Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut
| | - Diego González-Halphen
- Instituto de Fisiología Celular, Departamento de Genética Molecular Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Louise A Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut
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21
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Smith DR, Hua J, Archibald JM, Lee RW. Palindromic genes in the linear mitochondrial genome of the nonphotosynthetic green alga Polytomella magna. Genome Biol Evol 2014; 5:1661-7. [PMID: 23940100 PMCID: PMC3787674 DOI: 10.1093/gbe/evt122] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Organelle DNA is no stranger to palindromic repeats. But never has a mitochondrial or plastid genome been described in which every coding region is part of a distinct palindromic unit. While sequencing the mitochondrial DNA of the nonphotosynthetic green alga Polytomella magna, we uncovered precisely this type of genic arrangement. The P. magna mitochondrial genome is linear and made up entirely of palindromes, each containing 1–7 unique coding regions. Consequently, every gene in the genome is duplicated and in an inverted orientation relative to its partner. And when these palindromic genes are folded into putative stem-loops, their predicted translational start sites are often positioned in the apex of the loop. Gel electrophoresis results support the linear, 28-kb monomeric conformation of the P. magna mitochondrial genome. Analyses of other Polytomella taxa suggest that palindromic mitochondrial genes were present in the ancestor of the Polytomella lineage and lost or retained to various degrees in extant species. The possible origins and consequences of this bizarre genomic architecture are discussed.
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Affiliation(s)
- David Roy Smith
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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22
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Abstract
Recently, it was shown that gene conversion between the ends of linear mitochondrial chromosomes can cause telomere expansion and the duplication of subtelomeric loci. However, it is not yet known how widespread this phenomenon is and how significantly it has impacted organelle genome architecture. Using linear mitochondrial DNAs and mitochondrial plasmids from diverse eukaryotes, we argue that telomeric recombination has played a major role in fashioning linear organelle chromosomes. We find that mitochondrial telomeres frequently expand into subtelomeric regions, resulting in gene duplications, homogenizations, and/or fragmentations. We suggest that these features are a product of subtelomeric gene conversion, provide a hypothetical model for this process, and employ genetic diversity data to support the idea that the greater the effective population size the greater the potential for gene conversion between subtelomeric loci.
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Affiliation(s)
- David Roy Smith
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada.
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23
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Doublet V, Helleu Q, Raimond R, Souty-Grosset C, Marcadé I. Inverted repeats and genome architecture conversions of terrestrial isopods mitochondrial DNA. J Mol Evol 2013; 77:107-18. [PMID: 24068302 DOI: 10.1007/s00239-013-9587-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
Abstract
Mitochondrial DNA (mtDNA) is usually depicted as a circular molecule, however, there is increasing evidence that linearization of mtDNA evolved independently many times in organisms such as fungi, unicellular eukaryotes, and animals. Recent observations in various models with linear mtDNA revealed the presence of conserved inverted repeats (IR) at both ends that, when they become single-stranded, may be able to fold on themselves to create telomeric-hairpins involved in genome architecture conversions. The atypical mtDNA of terrestrial isopods (Crustacea: Oniscidea) composed of linear monomers and circular dimers is an interesting model to study genome architecture conversions. Here, we present the mtDNA control region sequences of two species of the genus Armadillidium: A. vulgare and A. pelagicum. All features of arthropods mtDNA control regions are present (origin of replication, poly-T stretch, GA and TA-rich blocks and one variable domain), plus a conserved IR. This IR can potentially fold into a hairpin structure and is present in two different orientations among the A. vulgare populations: either in one sense or in its reverse complement. This polymorphism, also observed in a single individual (heteroplasmy), might be a signature of genome architecture conversions from linear to circular monomeric mtDNA via successive opening and closing of the molecules.
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Affiliation(s)
- Vincent Doublet
- Equipe Ecologie Evolution Symbiose, Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Université de Poitiers, 40 Avenue du Recteur Pineau, 86022, Poitiers Cedex, France,
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24
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Hamaji T, Smith DR, Noguchi H, Toyoda A, Suzuki M, Kawai-Toyooka H, Fujiyama A, Nishii I, Marriage T, Olson BJSC, Nozaki H. Mitochondrial and plastid genomes of the colonial green alga Gonium pectorale give insights into the origins of organelle DNA architecture within the volvocales. PLoS One 2013; 8:e57177. [PMID: 23468928 PMCID: PMC3582580 DOI: 10.1371/journal.pone.0057177] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/18/2013] [Indexed: 02/07/2023] Open
Abstract
Volvocalean green algae have among the most diverse mitochondrial and plastid DNAs (mtDNAs and ptDNAs) from the eukaryotic domain. However, nearly all of the organelle genome data from this group are restricted to unicellular species, like Chlamydomonas reinhardtii, and presently only one multicellular species, the ∼4,000-celled Volvox carteri, has had its organelle DNAs sequenced. The V. carteri organelle genomes are repeat rich, and the ptDNA is the largest plastome ever sequenced. Here, we present the complete mtDNA and ptDNA of the colonial volvocalean Gonium pectorale, which is comprised of ∼16 cells and occupies a phylogenetic position closer to that of V. carteri than C. reinhardtii within the volvocine line. The mtDNA and ptDNA of G. pectorale are circular-mapping AT-rich molecules with respective lengths and coding densities of 16 and 222.6 kilobases and 73 and 44%. They share some features with the organelle DNAs of V. carteri, including palindromic repeats within the plastid compartment, but show more similarities with those of C. reinhardtii, such as a compact mtDNA architecture and relatively low organelle DNA intron contents. Overall, the G. pectorale organelle genomes raise several interesting questions about the origin of linear mitochondrial chromosomes within the Volvocales and the relationship between multicellularity and organelle genome expansion.
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Affiliation(s)
- Takashi Hamaji
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto, Japan
| | - David R. Smith
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hideki Noguchi
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Atsushi Toyoda
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Masahiro Suzuki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Asao Fujiyama
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Ichiro Nishii
- Temasek Life Sciences Laboratory, The National University of Singapore, Singapore, Singapore
| | - Tara Marriage
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Bradley J. S. C. Olson
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
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25
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Smith DR. Updating our view of organelle genome nucleotide landscape. Front Genet 2012; 3:175. [PMID: 22973299 PMCID: PMC3438683 DOI: 10.3389/fgene.2012.00175] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/20/2012] [Indexed: 01/25/2023] Open
Abstract
Organelle genomes show remarkable variation in architecture and coding content, yet their nucleotide composition is relatively unvarying across the eukaryotic domain, with most having a high adenine and thymine (AT) content. Recent studies, however, have uncovered guanine and cytosine (GC)-rich mitochondrial and plastid genomes. These sequences come from a small but eclectic list of species, including certain green plants and animals. Here, I review GC-rich organelle DNAs and the insights they have provided into the evolution of nucleotide landscape. I emphasize that GC-biased mitochondrial and plastid DNAs are more widespread than once thought, sometimes occurring together in the same species, and suggest that the forces biasing their nucleotide content can differ both among and within lineages, and may be associated with specific genome architectural features and life history traits.
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Affiliation(s)
- David Roy Smith
- Department of Botany, Canadian Institute for Advanced Research, University of British Columbia Vancouver, British Columbia, Canada
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26
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Lineage-specific fragmentation and nuclear relocation of the mitochondrial cox2 gene in chlorophycean green algae (Chlorophyta). Mol Phylogenet Evol 2012; 64:166-76. [PMID: 22724135 DOI: 10.1016/j.ympev.2012.03.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In most eukaryotes the subunit 2 of cytochrome c oxidase (COX2) is encoded in intact mitochondrial genes. Some green algae, however, exhibit split cox2 genes (cox2a and cox2b) encoding two polypeptides (COX2A and COX2B) that form a heterodimeric COX2 subunit. Here, we analyzed the distribution of intact and split cox2 gene sequences in 39 phylogenetically diverse green algae in phylum Chlorophyta obtained from databases (28 sequences from 22 taxa) and from new cox2 data generated in this work (23 sequences from 18 taxa). Our results support previous observations based on a smaller number of taxa, indicating that algae in classes Prasinophyceae, Ulvophyceae, and Trebouxiophyceae contain orthodox, intact mitochondrial cox2 genes. In contrast, all of the algae in Chlorophyceae that we examined exhibited split cox2 genes, and could be separated into two groups: one that has a mitochondrion-localized cox2a gene and a nucleus-localized cox2b gene ("Scenedesmus-like"), and another that has both cox2a and cox2b genes in the nucleus ("Chlamydomonas-like"). The location of the split cox2a and cox2b genes was inferred using five different criteria: differences in amino acid sequences, codon usage (mitochondrial vs. nuclear), codon preference (third position frequencies), presence of nucleotide sequences encoding mitochondrial targeting sequences and presence of spliceosomal introns. Distinct green algae could be grouped according to the form of cox2 gene they contain: intact or fragmented, mitochondrion- or nucleus-localized, and intron-containing or intron-less. We present a model describing the events that led to mitochondrial cox2 gene fragmentation and the independent and sequential migration of cox2a and cox2b genes to the nucleus in chlorophycean green algae. We also suggest that the distribution of the different forms of the cox2 gene provides important insights into the phylogenetic relationships among major groups of Chlorophyceae.
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Valach M, Pryszcz LP, Tomaska L, Gacser A, Gabaldón T, Nosek J. Mitochondrial genome variability within the Candida parapsilosis species complex. Mitochondrion 2012; 12:514-9. [DOI: 10.1016/j.mito.2012.07.109] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 04/05/2012] [Accepted: 07/13/2012] [Indexed: 01/15/2023]
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Abstract
Genomic analyses increasingly make use of sophisticated statistical and computational approaches in investigations of genomic function and evolution. Scientists implementing and developing these approaches are often computational scientists, physicists, or mathematicians. This article aims to provide a compact overview of genome biology for these scientists. Thus, the article focuses on providing biological context to the genomic features, processes, and structures analysed by these approaches. Topics covered include (1) differences between eukaryotic and prokaryotic cells; (2) the physical structure of genomes and chromatin; (3) different categories of genomic regions, including those serving as templates for RNA and protein synthesis, regulatory regions, repetitive regions, and "architectural" or "organisational" regions, such as centromeres and telomeres; (4) the cell cycle; (5) an overview of transcription, translation, and protein structure; and (6) a glossary of relevant terms.
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Complete sequences of the mitochondrial DNA of the wild Gracilariopsis lemaneiformis and two mutagenic cultivated breeds (Gracilariaceae, Rhodophyta). PLoS One 2012; 7:e40241. [PMID: 22768261 PMCID: PMC3386957 DOI: 10.1371/journal.pone.0040241] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/03/2012] [Indexed: 11/25/2022] Open
Abstract
The complete mitochondrial DNA (mtDNA) of Gracilariopsis lemaneiformis was sequenced (25883 bp) and mapped to a circular model. The A+T composition was 72.5%. Forty six genes and two potentially functional open reading frames were identified. They include 24 protein-coding genes, 2 rRNA genes, 20 tRNA genes and 2 ORFs (orf60, orf142). There is considerable sequence synteny across the five red algal mtDNAs falling into Florideophyceae including Gr. lemaneiformis in this study and previously sequenced species. A long stem-loop and a hairpin structure were identified in intergenic regions of mt genome of Gr. lemaneiformis, which are believed to be involved with transcription and replication. In addition, the mtDNAs of two mutagenic cultivated breeds (“981” and “07-2”) were also sequenced. Compared with the mtDNA of wild Gr. lemaneiformis, the genome size and gene length and order of three strains were completely identical except nine base mutations including eight in the protein-coding genes and one in the tRNA gene. None of the base mutations caused frameshift or a premature stop codon in the mtDNA genes. Phylogenetic analyses based on mitochondrial protein-coding genes and rRNA genes demonstrated Gracilariopsis andersonii had closer phylogenetic relationship with its parasite Gracilariophila oryzoides than Gracilariopsis lemaneiformis which was from the same genus of Gracilariopsis.
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Mower JP, Case AL, Floro ER, Willis JH. Evidence against equimolarity of large repeat arrangements and a predominant master circle structure of the mitochondrial genome from a monkeyflower (Mimulus guttatus) lineage with cryptic CMS. Genome Biol Evol 2012; 4:670-86. [PMID: 22534162 PMCID: PMC3381676 DOI: 10.1093/gbe/evs042] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Despite intense investigation for over 25 years, the in vivo structure of plant mitochondrial genomes remains uncertain. Mapping studies and genome sequencing generally produce large circular chromosomes, whereas electrophoretic and microscopic studies typically reveal linear and multibranched molecules. To more fully assess the structure of plant mitochondrial genomes, the complete sequence of the monkeyflower (Mimulus guttatus DC. line IM62) mitochondrial DNA was constructed from a large (35 kb) paired-end shotgun sequencing library to a high depth of coverage (∼30×). The complete genome maps as a 525,671 bp circular molecule and exhibits a fairly conventional set of features including 62 genes (encoding 35 proteins, 24 transfer RNAs, and 3 ribosomal RNAs), 22 introns, 3 large repeats (2.7, 9.6, and 29 kb), and 96 small repeats (40–293 bp). Most paired-end reads (71%) mapped to the consensus sequence at the expected distance and orientation across the entire genome, validating the accuracy of assembly. Another 10% of reads provided clear evidence of alternative genomic conformations due to apparent rearrangements across large repeats. Quantitative assessment of these repeat-spanning read pairs revealed that all large repeat arrangements are present at appreciable frequencies in vivo, although not always in equimolar amounts. The observed stoichiometric differences for some arrangements are inconsistent with a predominant master circular structure for the mitochondrial genome of M. guttatus IM62. Finally, because IM62 contains a cryptic cytoplasmic male sterility (CMS) system, an in silico search for potential CMS genes was undertaken. The three chimeric open reading frames (ORFs) identified in this study, in addition to the previously identified ORFs upstream of the nad6 gene, are the most likely CMS candidate genes in this line.
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Affiliation(s)
- Jeffrey P Mower
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska, NE, USA.
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Smith DR, Kayal E, Yanagihara AA, Collins AG, Pirro S, Keeling PJ. First complete mitochondrial genome sequence from a box jellyfish reveals a highly fragmented linear architecture and insights into telomere evolution. Genome Biol Evol 2011; 4:52-8. [PMID: 22117085 PMCID: PMC3268669 DOI: 10.1093/gbe/evr127] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Animal mitochondrial DNAs (mtDNAs) are typically single circular chromosomes, with the exception of those from medusozoan cnidarians (jellyfish and hydroids), which are linear and sometimes fragmented. Most medusozoans have linear monomeric or linear bipartite mitochondrial genomes, but preliminary data have suggested that box jellyfish (cubozoans) have mtDNAs that consist of many linear chromosomes. Here, we present the complete mtDNA sequence from the winged box jellyfish Alatina moseri (the first from a cubozoan). This genome contains unprecedented levels of fragmentation: 18 unique genes distributed over eight 2.9- to 4.6-kb linear chromosomes. The telomeres are identical within and between chromosomes, and recombination between subtelomeric sequences has led to many genes initiating or terminating with sequences from other genes (the most extreme case being 150 nt of a ribosomal RNA containing the 5′ end of nad2), providing evidence for a gene conversion–based model of telomere evolution. The silent-site nucleotide variation within the A. moseri mtDNA is among the highest observed from a eukaryotic genome and may be associated with elevated rates of recombination.
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Affiliation(s)
- David Roy Smith
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada.
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Smith DR, Lee RW. Nucleotide diversity of the colorless green alga Polytomella parva (Chlorophyceae, Chlorophyta): high for the mitochondrial telomeres, surprisingly low everywhere else. J Eukaryot Microbiol 2011; 58:471-3. [PMID: 21762422 DOI: 10.1111/j.1550-7408.2011.00569.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Silent-site nucleotide diversity data (π(silent)) can provide insights into the forces driving genome evolution. Here we present π(silent) statistics for the mitochondrial and nuclear DNAs of Polytomella parva, a nonphotosynthetic green alga with a highly reduced, linear fragmented mitochondrial genome. We show that this species harbors very little genetic diversity, with the exception of the mitochondrial telomeres, which have an excess of polymorphic sites. These data are compared with previously published π(silent) values from the mitochondrial and nuclear genomes of the model species Chlamydomonas reinhardtii and Volvox carteri, which are close relatives of P. parva, and are used to understand the modes and tempos of genome evolution within green algae.
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Affiliation(s)
- David Roy Smith
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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