19 results on '"Obornik, M"'
Search Results
2. The cell wall polysaccharides of a photosynthetic relative of apicomplexans, Chromera velia
- Author
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Kroth, P, Tortorelli, G, Pettolino, F, Lai, D-H, Tomcala, A, Bacic, A, Obornik, M, Lukes, J, McFadden, G, Kroth, P, Tortorelli, G, Pettolino, F, Lai, D-H, Tomcala, A, Bacic, A, Obornik, M, Lukes, J, and McFadden, G
- Abstract
Chromerids are a group of alveolates, found in corals, that show peculiar morphological and genomic features. These organisms are evolutionary placed in-between symbiotic dinoflagellates and parasitic apicomplexans. There are two known species of chromerids: Chromera velia and Vitrella brassicaformis. Here, the biochemical composition of the C. velia cell wall was analyzed. Several polysaccharides adorn this structure, with glucose being the most abundant monosaccharide (approx. 80%) and predominantly 4-linked (approx. 60%), suggesting that the chromerids cell wall is mostly cellulosic. The presence of cellulose was cytochemically confirmed with calcofluor white staining of the algal cell. The remaining wall polysaccharides, assuming structures are similar to those of higher plants, are indicative of a mixture of galactans, xyloglucans, heteroxylans, and heteromannans. The present work provides, for the first time, insights into the outermost layers of the photosynthetic alveolate C. velia.
- Published
- 2021
3. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites
- Author
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Woo, YH, Ansari, H, Otto, TD, Klinger, CM, Kolisko, M, Michalek, J, Saxena, A, Shanmugam, D, Tayyrov, A, Veluchamy, A, Ali, S, Bernal, A, del Campo, J, Cihlar, J, Flegontov, P, Gornik, SG, Hajduskova, E, Horak, A, Janouskovec, J, Katris, NJ, Mast, FD, Miranda-Saavedra, D, Mourier, T, Naeem, R, Nair, M, Panigrahi, AK, Rawlings, ND, Padron-Regalado, E, Ramaprasad, A, Samad, N, Tomcala, A, Wilkes, J, Neafsey, DE, Doerig, C, Bowler, C, Keeling, PJ, Roos, DS, Dacks, JB, Templeton, TJ, Waller, RF, Lukes, J, Obornik, M, Pain, A, Woo, YH, Ansari, H, Otto, TD, Klinger, CM, Kolisko, M, Michalek, J, Saxena, A, Shanmugam, D, Tayyrov, A, Veluchamy, A, Ali, S, Bernal, A, del Campo, J, Cihlar, J, Flegontov, P, Gornik, SG, Hajduskova, E, Horak, A, Janouskovec, J, Katris, NJ, Mast, FD, Miranda-Saavedra, D, Mourier, T, Naeem, R, Nair, M, Panigrahi, AK, Rawlings, ND, Padron-Regalado, E, Ramaprasad, A, Samad, N, Tomcala, A, Wilkes, J, Neafsey, DE, Doerig, C, Bowler, C, Keeling, PJ, Roos, DS, Dacks, JB, Templeton, TJ, Waller, RF, Lukes, J, Obornik, M, and Pain, A
- Abstract
The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga.
- Published
- 2015
4. The Phaeodactylum genome reveals the evolutionary history of diatom genomes
- Author
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Bowler, C., Allan, A. E., Badger, J. H., Grimwood, J., Jabbari, K., Kuo, A., Maheshwari, U., Martens, C., Maumus, F., Otillar, R. P., Rayko, E., Salamov, A., Vandepoele, K., Beszeri, B., Gruber, A., Heijde, M., Katinka, M., Mock, Thomas, Valentin, Klaus-Ulrich, Verret, F., Berges, J. A., Brownlee, C., Chiovitti, A., Jae Choi, C., Coesel, S., De Martino, A., Detter, J. C., Durkin, C., Falciatore, A., Fournet, J., Haruta, M., Huysman, M. J. J., Jenkins, B. D., Jiroutova, K., Jorgensen, R. E., Joubert, Y., Kaplan, A., Kröger, N., Kroth, P. G., La Roche, J., Lindquiste, E., Lommer, M., Martin-Jézéquel, V., Lopez, P. J., Lucas, S., Mangogna, M., McGinnis, K., Medlin, Linda, Monsant, A., Oudot-Le Secq, M.-P., Napoli, C., Obornik, M., Petit, J.-L., Porcel, B. M., Poulsen, N., Robison, M., Rychlewski, L., Rynearson, T. A., Schmutz, J., Schnitzler Parker, M., Shapiro, H., Siaur, M., Stanley, M., Sussman, M. J., Taylor, A. R., Vardi, A., von Dassow, P., Vyverman, W., Willis, A., Wyrwicz, L. S., Rokhsar, D. S., Weissenbach, J., Armbrust, E. V., Green, B. R., Van de Peer, Y., Grigoriev, I. V., and Cadoret, J.-P.
- Published
- 2008
5. Molecular characterization and phylogeny of the entomopathogenic fungus Aschersonia spp
- Author
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Obornik, M., Stouthamer, R., Meekes, E., and Schilthuizen, M.
- Subjects
Life Science ,Laboratory of Entomology ,PE&RC ,Laboratorium voor Entomologie - Published
- 1999
6. The Phaeodactylum genome reveals the evolutionary history of diatom genomes
- Author
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Bowler, C, Allen, A, Badger, J, Grimwood, J, Jabbari, K, Kuo, A, Maheswari, U, Martens, C, Maumus, F, Otillar, R, Rayko, E, Salamov, A, Vandepoele, K, Beszteri, B, Gruber, A, Heijde, M, Katinka, M, Mock, T, Valentin, K, Verret, F, Berges, J, Brownlee, C, Cadoret, Jean-paul, Chiovitti, A, Choi, C, Coesel, S, De Martino, A, Detter, J, Durkin, C, Falciatore, A, Fournet, J, Haruta, M, Huysman, M, Jenkins, B, Jiroutova, K, Jorgensen, R, Joubert, Y, Kaplan, A, Kroger, N, Kroth, P, La Roche, J, Lindquist, E, Lommer, M, Martin Jezequel, V, Lopez, P, Lucas, S, Mangogna, M, Mcginnis, K, Medlin, L, Montsant, A, Oudot Le Secq, M, Napoli, C, Obornik, M, Parker, M, Petit, J, Porcel, B, Poulsen, N, Robison, M, Rychlewski, L, Rynearson, T, Schmutz, J, Shapiro, H, Siaut, M, Stanley, M, Sussman, M, Taylor, A, Vardi, A, Von Dassow, P, Vyverman, W, Willis, A, Wyrwicz, L, Rokhsar, D, Weissenbach, J, Armbrust, E, Green, B, Van De Peer, Y, Grigoriev Iv, Bowler, C, Allen, A, Badger, J, Grimwood, J, Jabbari, K, Kuo, A, Maheswari, U, Martens, C, Maumus, F, Otillar, R, Rayko, E, Salamov, A, Vandepoele, K, Beszteri, B, Gruber, A, Heijde, M, Katinka, M, Mock, T, Valentin, K, Verret, F, Berges, J, Brownlee, C, Cadoret, Jean-paul, Chiovitti, A, Choi, C, Coesel, S, De Martino, A, Detter, J, Durkin, C, Falciatore, A, Fournet, J, Haruta, M, Huysman, M, Jenkins, B, Jiroutova, K, Jorgensen, R, Joubert, Y, Kaplan, A, Kroger, N, Kroth, P, La Roche, J, Lindquist, E, Lommer, M, Martin Jezequel, V, Lopez, P, Lucas, S, Mangogna, M, Mcginnis, K, Medlin, L, Montsant, A, Oudot Le Secq, M, Napoli, C, Obornik, M, Parker, M, Petit, J, Porcel, B, Poulsen, N, Robison, M, Rychlewski, L, Rynearson, T, Schmutz, J, Shapiro, H, Siaut, M, Stanley, M, Sussman, M, Taylor, A, Vardi, A, Von Dassow, P, Vyverman, W, Willis, A, Wyrwicz, L, Rokhsar, D, Weissenbach, J, Armbrust, E, Green, B, Van De Peer, Y, and Grigoriev Iv
- Abstract
Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one- fifth of the primary productivity on Earth(1,2). The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology(3-5). Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes (similar to 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.
- Published
- 2008
- Full Text
- View/download PDF
7. The Phaeodactylum genome reveals the evolutionary history of diatom genomes
- Author
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Cadoret, J.-P., Bowler, C., Allan, A. E., Badger, J. H., Grimwood, J., Jabbari, K., Kuo, A., Maheshwari, U., Martens, C., Maumus, F., Otillar, R. P., Rayko, E., Salamov, A., Vandepoele, K., Beszeri, B., Gruber, A., Heijde, M., Katinka, M., Mock, Thomas, Valentin, Klaus-Ulrich, Verret, F., Berges, J. A., Brownlee, C., Chiovitti, A., Jae Choi, C., Coesel, S., De Martino, A., Detter, J. C., Durkin, C., Falciatore, A., Fournet, J., Haruta, M., Huysman, M. J. J., Jenkins, B. D., Jiroutova, K., Jorgensen, R. E., Joubert, Y., Kaplan, A., Kröger, N., Kroth, P. G., La Roche, J., Lindquiste, E., Lommer, M., Martin-Jézéquel, V., Lopez, P. J., Lucas, S., Mangogna, M., McGinnis, K., Medlin, Linda, Monsant, A., Oudot-Le Secq, M.-P., Napoli, C., Obornik, M., Petit, J.-L., Porcel, B. M., Poulsen, N., Robison, M., Rychlewski, L., Rynearson, T. A., Schmutz, J., Schnitzler Parker, M., Shapiro, H., Siaur, M., Stanley, M., Sussman, M. J., Taylor, A. R., Vardi, A., von Dassow, P., Vyverman, W., Willis, A., Wyrwicz, L. S., Rokhsar, D. S., Weissenbach, J., Armbrust, E. V., Green, B. R., Van de Peer, Y., Grigoriev, I. V., Cadoret, J.-P., Bowler, C., Allan, A. E., Badger, J. H., Grimwood, J., Jabbari, K., Kuo, A., Maheshwari, U., Martens, C., Maumus, F., Otillar, R. P., Rayko, E., Salamov, A., Vandepoele, K., Beszeri, B., Gruber, A., Heijde, M., Katinka, M., Mock, Thomas, Valentin, Klaus-Ulrich, Verret, F., Berges, J. A., Brownlee, C., Chiovitti, A., Jae Choi, C., Coesel, S., De Martino, A., Detter, J. C., Durkin, C., Falciatore, A., Fournet, J., Haruta, M., Huysman, M. J. J., Jenkins, B. D., Jiroutova, K., Jorgensen, R. E., Joubert, Y., Kaplan, A., Kröger, N., Kroth, P. G., La Roche, J., Lindquiste, E., Lommer, M., Martin-Jézéquel, V., Lopez, P. J., Lucas, S., Mangogna, M., McGinnis, K., Medlin, Linda, Monsant, A., Oudot-Le Secq, M.-P., Napoli, C., Obornik, M., Petit, J.-L., Porcel, B. M., Poulsen, N., Robison, M., Rychlewski, L., Rynearson, T. A., Schmutz, J., Schnitzler Parker, M., Shapiro, H., Siaur, M., Stanley, M., Sussman, M. J., Taylor, A. R., Vardi, A., von Dassow, P., Vyverman, W., Willis, A., Wyrwicz, L. S., Rokhsar, D. S., Weissenbach, J., Armbrust, E. V., Green, B. R., Van de Peer, Y., and Grigoriev, I. V.
- Published
- 2008
8. The genome of the diatom Thalassiosira pseudonana: ecology, evolution, and metabolism
- Author
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Armbrust, E. V., Berges, J. A., Bowler, C., Green, B. R., Martinez, D., Putnam, N. H., Zhou, S., Allen, A. E., Apt, K. E., Bechner, M., Brzezinski, M. A., Chaal, B. K., Chiovitti, A., Davis, A. K., Demarest, M. S., Detter, J. C., Glavina, T., Goodstein, D., Hadi, M. Z., Hellsten, U., Hildebrand, M., Jenkins, B. D., Jurka, J., Kapitonov, V. V., Kroeger, N., Lau, W. W., Lane, T. W., Larimer, F. W., Lippmeier, J. C., Lucas, S., Medina, M., Montsant, A., Obornik, M., Parker, M. S., Palenik, B., Pazour, G. J., Richardson, P. M., Rynearson, T. A., Saito, M. A., Schwartz, D. C., Thamatrakoln, K., Valentin, Klaus-Ulrich, Vardi, A., Wilkerson, F. P., Rokhsar, D. S., Armbrust, E. V., Berges, J. A., Bowler, C., Green, B. R., Martinez, D., Putnam, N. H., Zhou, S., Allen, A. E., Apt, K. E., Bechner, M., Brzezinski, M. A., Chaal, B. K., Chiovitti, A., Davis, A. K., Demarest, M. S., Detter, J. C., Glavina, T., Goodstein, D., Hadi, M. Z., Hellsten, U., Hildebrand, M., Jenkins, B. D., Jurka, J., Kapitonov, V. V., Kroeger, N., Lau, W. W., Lane, T. W., Larimer, F. W., Lippmeier, J. C., Lucas, S., Medina, M., Montsant, A., Obornik, M., Parker, M. S., Palenik, B., Pazour, G. J., Richardson, P. M., Rynearson, T. A., Saito, M. A., Schwartz, D. C., Thamatrakoln, K., Valentin, Klaus-Ulrich, Vardi, A., Wilkerson, F. P., and Rokhsar, D. S.
- Published
- 2004
9. Genome Sequence of the Marine Photoheterotrophic Bacterium Erythrobacter sp. Strain NAP1
- Author
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Koblizek, M., primary, Janouskovec, J., additional, Obornik, M., additional, Johnson, J. H., additional, Ferriera, S., additional, and Falkowski, P. G., additional
- Published
- 2011
- Full Text
- View/download PDF
10. Phylogenetic analysis of Sarcocystis spp. of mammals and reptiles supports the coevolution of Sarcocystis spp. with their final hosts
- Author
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Doležel, D., Koudela, B., Jirků, M., Hypša, V., Obornı́k, M., Votýpka, J., Modrý, D., Šlapeta, J.R., and Lukeš, J.
- Published
- 1999
- Full Text
- View/download PDF
11. Phylogenetic relationship of Trypanosoma corvi with other avian trypanosomes
- Author
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Votypka, J., Julius Lukes, and Obornik, M.
12. General principles of supporting mine openings from the point of view of rock as a load-bearing element
- Author
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Obornik, M., primary
- Published
- 1974
- Full Text
- View/download PDF
13. Biochemical and genotyping analyses of camels (Camelus dromedaries) trypanosomiasis in North Africa.
- Author
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Darwish AM, Sharaf A, Gaouar SBS, Ali NI, El-Aziz THA, Abushady AM, Kaouadji Z, Othman OE, and Obornik M
- Subjects
- Animals, Camelus, Phylogeny, Genotype, Africa, Northern, Antioxidants, Superoxide Dismutase genetics, Trypanosomiasis epidemiology, Trypanosomiasis veterinary, Trypanosoma genetics
- Abstract
Camels are considered an important food source in North Africa. Trypanosomiasis in camels is a life-threatening disease that causes severe economic losses in milk and meat production. Therefore, the objective of this study was to determine the trypanosome genotypes in the North African region. Trypanosome infection rates were determined by microscopic examination of blood smears and polymerase chain reaction (PCR). In addition, total antioxidant capacity (TAC), lipid peroxides (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were determined in erythrocyte lysate. Furthermore, 18S amplicon sequencing was used to barcode and characterizes the genetic diversity of trypanosome genotypes in camel blood. In addition to Trypanosoma, Babesia and Thelieria were also detected in the blood samples. PCR showed that the trypanosome infection rate was higher in Algerian samples (25.7%) than in Egyptian samples (7.2%). Parameters such as MDA, GSH, SOD and CAT had significantly increased in camels infected with trypanosomes compared to uninfected control animals, while TAC level was not significantly changed. The results of relative amplicon abundance showed that the range of trypanosome infection was higher in Egypt than in Algeria. Moreover, phylogenetic analysis showed that the Trypanosoma sequences of Egyptian and Algerian camels are related to Trypanosoma evansi. Unexpectedly, diversity within T. evansi was higher in Egyptian camels than in Algerian camels. We present here the first molecular report providing a picture of trypanosomiasis in camels, covering wide geographical areas in Egypt and Algeria., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
14. Genome-enabled phylogenetic and functional reconstruction of an araphid pennate diatom Plagiostriata sp. CCMP470, previously assigned as a radial centric diatom, and its bacterial commensal.
- Author
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Sato S, Nanjappa D, Dorrell RG, Vieira FRJ, Kazamia E, Tirichine L, Veluchamy A, Heilig R, Aury JM, Jaillon O, Wincker P, Fussy Z, Obornik M, Muñoz-Gómez SA, Mann DG, Bowler C, and Zingone A
- Subjects
- Biological Evolution, Evolution, Molecular, Genome, Phylogeny, Transcriptome genetics, Diatoms classification, Diatoms genetics, Gene Expression Profiling methods
- Abstract
Diatoms are an ecologically fundamental and highly diverse group of algae, dominating marine primary production in both open-water and coastal communities. The diatoms include both centric species, which may have radial or polar symmetry, and the pennates, which include raphid and araphid species and arose within the centric lineage. Here, we use combined microscopic and molecular information to reclassify a diatom strain CCMP470, previously annotated as a radial centric species related to Leptocylindrus danicus, as an araphid pennate species in the staurosiroid lineage, within the genus Plagiostriata. CCMP470 shares key ultrastructural features with Plagiostriata taxa, such as the presence of a sternum with parallel striae, and the presence of a highly reduced labiate process on its valve; and this evolutionary position is robustly supported by multigene phylogenetic analysis. We additionally present a draft genome of CCMP470, which is the first genome available for a staurosiroid lineage. 270 Pfams (19%) found in the CCMP470 genome are not known in other diatom genomes, which otherwise does not hold big novelties compared to genomes of non-staurosiroid diatoms. Notably, our DNA library contains the genome of a bacterium within the Rhodobacterales, an alpha-proteobacterial lineage known frequently to associate with algae. We demonstrate the presence of commensal alpha-proteobacterial sequences in other published algal genome and transcriptome datasets, which may indicate widespread and persistent co-occurrence.
- Published
- 2020
- Full Text
- View/download PDF
15. How many species of whipworms do we share? Whipworms from man and other primates form two phylogenetic lineages.
- Author
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Dolezalova J, Obornik M, Hajduskova E, Jirku M, Petrzelkova KJ, Bolechova P, Cutillas C, Callejon R, Jozef J, Berankova Z, and Modry D
- Published
- 2015
- Full Text
- View/download PDF
16. Molecular identification and genotyping of Microsporidia in selected hosts.
- Author
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Valencakova A, Balent P, Ravaszova P, Horak A, Obornik M, Halanova M, Malcekova B, Novotny F, and Goldova M
- Subjects
- Animals, DNA Primers genetics, Encephalitozoon genetics, Encephalitozoonosis diagnosis, Mice, Mice, Inbred BALB C, Rabbits, Swine, Encephalitozoon classification, Encephalitozoon isolation & purification, Encephalitozoonosis veterinary, Molecular Diagnostic Techniques methods, Polymerase Chain Reaction methods, Veterinary Medicine methods
- Abstract
The work is described by microscopic analysis, the serological analysis (IFAT) and the molecular analysis of isolates from clinical samples (blood, faeces and urine) from ten domestic rabbits (Oryctolagus cuniculus), breed Maličký, four New Zealand domestic rabbits, 11 sows of breed Slo0076akian Improved White and 15 clinically healthy laboratory BALB/c mice. The aim of the study was to validate the suitability of species-unspecific primer pairs 530F and 580R for genotype determination of the Microsporidia strain and species-specific primer pairs ECUNF and ECUNR, SINTF and SINTR and EBIER1 and EBIEF1 for the determination of E ncephalitozoon cuniculi, Encephalitozoon intestinalis and Enterocytozoon bieneusi species for diagnostic purposes. Sequences of animals were compared with those from the GenBank database. In rabbits, two murine genotypes II and four canine genotypes III were identified. Genotype II was identified in mice. The Encephalitozoon intestinalis identified in the sample from swine showed no genetic heterogeneity.
- Published
- 2012
- Full Text
- View/download PDF
17. The Phaeodactylum genome reveals the evolutionary history of diatom genomes.
- Author
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Bowler C, Allen AE, Badger JH, Grimwood J, Jabbari K, Kuo A, Maheswari U, Martens C, Maumus F, Otillar RP, Rayko E, Salamov A, Vandepoele K, Beszteri B, Gruber A, Heijde M, Katinka M, Mock T, Valentin K, Verret F, Berges JA, Brownlee C, Cadoret JP, Chiovitti A, Choi CJ, Coesel S, De Martino A, Detter JC, Durkin C, Falciatore A, Fournet J, Haruta M, Huysman MJ, Jenkins BD, Jiroutova K, Jorgensen RE, Joubert Y, Kaplan A, Kröger N, Kroth PG, La Roche J, Lindquist E, Lommer M, Martin-Jézéquel V, Lopez PJ, Lucas S, Mangogna M, McGinnis K, Medlin LK, Montsant A, Oudot-Le Secq MP, Napoli C, Obornik M, Parker MS, Petit JL, Porcel BM, Poulsen N, Robison M, Rychlewski L, Rynearson TA, Schmutz J, Shapiro H, Siaut M, Stanley M, Sussman MR, Taylor AR, Vardi A, von Dassow P, Vyverman W, Willis A, Wyrwicz LS, Rokhsar DS, Weissenbach J, Armbrust EV, Green BR, Van de Peer Y, and Grigoriev IV
- Subjects
- DNA, Algal analysis, Genes, Bacterial genetics, Molecular Sequence Data, Protein Structure, Tertiary, Sequence Homology, Amino Acid, Signal Transduction, Diatoms genetics, Evolution, Molecular, Genome genetics
- Abstract
Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes ( approximately 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.
- Published
- 2008
- Full Text
- View/download PDF
18. The genome of the diatom Thalassiosira pseudonana: ecology, evolution, and metabolism.
- Author
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Armbrust EV, Berges JA, Bowler C, Green BR, Martinez D, Putnam NH, Zhou S, Allen AE, Apt KE, Bechner M, Brzezinski MA, Chaal BK, Chiovitti A, Davis AK, Demarest MS, Detter JC, Glavina T, Goodstein D, Hadi MZ, Hellsten U, Hildebrand M, Jenkins BD, Jurka J, Kapitonov VV, Kröger N, Lau WW, Lane TW, Larimer FW, Lippmeier JC, Lucas S, Medina M, Montsant A, Obornik M, Parker MS, Palenik B, Pazour GJ, Richardson PM, Rynearson TA, Saito MA, Schwartz DC, Thamatrakoln K, Valentin K, Vardi A, Wilkerson FP, and Rokhsar DS
- Subjects
- Adaptation, Physiological, Algal Proteins chemistry, Algal Proteins genetics, Algal Proteins physiology, Animals, Cell Nucleus genetics, Chromosomes, DNA genetics, Diatoms chemistry, Diatoms cytology, Diatoms metabolism, Energy Metabolism, Iron metabolism, Light, Light-Harvesting Protein Complexes chemistry, Light-Harvesting Protein Complexes genetics, Light-Harvesting Protein Complexes metabolism, Mitochondria genetics, Molecular Sequence Data, Nitrogen metabolism, Photosynthesis, Plastids genetics, Restriction Mapping, Sequence Alignment, Silicic Acid metabolism, Symbiosis, Urea metabolism, Biological Evolution, Diatoms genetics, Ecosystem, Genome, Sequence Analysis, DNA
- Abstract
Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.
- Published
- 2004
- Full Text
- View/download PDF
19. Phylogeny of mitosporic entomopathogenic fungi: is the genus Paecilomyces polyphyletic?
- Author
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Obornik M, Jirku M, and Dolezel D
- Subjects
- 5' Untranslated Regions genetics, Animals, Genes, Fungal genetics, Genes, rRNA genetics, Paecilomyces genetics, Phylogeny, Insecta microbiology, Paecilomyces classification
- Abstract
We analyzed sequences of the divergent domain at the 5' end of the large subunit rRNA gene from the mitosporic entomopathogenic fungi Paecilomyces sp., Paecilomyces fumosoroseus, Paecilomyces farinosus, Paecilomyces lilacinus, Verticillium lecanii, Verticillium psalliotae, Beauveria bassiana, Aschersonia sp., Aschersonia placenta, ascomycetous Cordyceps sp., and Cordyceps militaris. Phylogenetic analysis showed P. fumosorseus as the best characterized out of the analyzed species with the B. bassiana clade as its sister group. Two of the P. farinosus isolates were invariably placed within the Verticillium cluster, which also contained C. militaris. The only analyzed P. lilacinus isolate appeared on the root of the hyphomycetous fungi and was characterized as the most distinct from all the hyphomycetous fungi tested. Polyphyly of the genus Paecilomyces was well supported by the Kishino-Hasegawa test. In all trees based on the small subunit rRNA gene sequences obtained from the GenBank, V. lecanii, V. psalliotae, P. fumosoroseus, P. tenuipes and B. bassiana form, together with that of C. militaris, the best supported cluster in the tree. The rest of Cordyceps spp. constitute a distinct clade. Phylogenetic relationships derived from both tested DNA regions show polyphyly of the genus Paecilomyces and close relationships among entomopathogenic species of the genera Verticillium, Paecilomyces, and Beauveria.
- Published
- 2001
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