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36 results on '"Armbrust, E. V."'

7. Comparative Genomic Analysis of Vibrio diabolicus and Six Taxonomic Synonyms: A First Look at the Distribution and Diversity of the Expanded Species

Author

Turner, Jeffrey W., primary, Tallman, James J., additional, Macias, Amanda, additional, Pinnell, Lee J., additional, Elledge, Nicole C., additional, Nasr Azadani, Danial, additional, Nilsson, William B., additional, Paranjpye, Rohinee N., additional, Armbrust, E. V., additional, and Strom, Mark S., additional

Published
2018
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11. Evolutionary genomics of the cold-Adapted diatom Fragilariopsis cylindrus

Author

Mock, T., Otillar, R. P., Strauss, Jan, McMullan, M., Paajanen, P., Schmutz, J., Salamov, A., Sanges, R., Toseland, A., Ward, B. J., Allen, A. E., Dupont, C. L., Frickenhaus, S., Maumus, F., Veluchamy, A., Wu, T., Barry, K. W., Falciatore, A., Ferrante, M. I., Fortunato, A. E., Glöckner, G., Gruber, A., Hipkin, R., Janech, M. G., Kroth, P. G., Leese, F., Lindquist, E. A., Lyon, B. R., Martin, J., Mayer, C., Parker, M., Quesneville, H., Raymond, J. A., Uhlig, C., Valas, R. E., Valentin, K. U., Worden, Alexandra Z., Armbrust, E. V., Clark, M. D., Bowler, C., Green, B. R., Moulton, V., Van Oosterhout, C., Grigoriev, I. V., Mock, T., Otillar, R. P., Strauss, Jan, McMullan, M., Paajanen, P., Schmutz, J., Salamov, A., Sanges, R., Toseland, A., Ward, B. J., Allen, A. E., Dupont, C. L., Frickenhaus, S., Maumus, F., Veluchamy, A., Wu, T., Barry, K. W., Falciatore, A., Ferrante, M. I., Fortunato, A. E., Glöckner, G., Gruber, A., Hipkin, R., Janech, M. G., Kroth, P. G., Leese, F., Lindquist, E. A., Lyon, B. R., Martin, J., Mayer, C., Parker, M., Quesneville, H., Raymond, J. A., Uhlig, C., Valas, R. E., Valentin, K. U., Worden, Alexandra Z., Armbrust, E. V., Clark, M. D., Bowler, C., Green, B. R., Moulton, V., Van Oosterhout, C., and Grigoriev, I. V.

Abstract

The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown. Here we present insights into the genome evolution of a cold-Adapted diatom from the Southern Ocean, Fragilariopsis cylindrus, based on a comparison with temperate diatoms. We find that approximately 24.7 per cent of the diploid F. cylindrus genome consists of genetic loci with alleles that are highly divergent (15.1 megabases of the total genome size of 61.1 megabases). These divergent alleles were differentially expressed across environmental conditions, including darkness, low iron, freezing, elevated temperature and increased CO 2 . Alleles with the largest ratio of non-synonymous to synonymous nucleotide substitutions also show the most pronounced condition-dependent expression, suggesting a correlation between diversifying selection and allelic differentiation. Divergent alleles may be involved in adaptation to environmental fluctuations in the Southern Ocean. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

Published
2017
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12. Probing the evolution, ecology and physiology of marine protists using transcriptomics

Author

Caron, D. A., Alexander, H., Allen, A. E., Archibald, J. M., Armbrust, E. V., Bachy, C., Bell, C. J., Bharti, A., Dyhrman, S. T., Guida, S. M., Heidelberg, K. B., Kaye, J. Z., Metzner, J., Smith, S. R., Worden, Alexandra Z., Caron, D. A., Alexander, H., Allen, A. E., Archibald, J. M., Armbrust, E. V., Bachy, C., Bell, C. J., Bharti, A., Dyhrman, S. T., Guida, S. M., Heidelberg, K. B., Kaye, J. Z., Metzner, J., Smith, S. R., and Worden, Alexandra Z.

Abstract

Protists, which are single-celled eukaryotes, critically influence the ecology and chemistry of marine ecosystems, but genome-based studies of these organisms have lagged behind those of other microorganisms. However, recent transcriptomic studies of cultured species, complemented by meta-omics analyses of natural communities, have increased the amount of genetic information available for poorly represented branches on the tree of eukaryotic life. This information is providing insights into the adaptations and interactions between protists and other microorganisms and macroorganisms, but many of the genes sequenced show no similarity to sequences currently available in public databases. A better understanding of these newly discovered genes will lead to a deeper appreciation of the functional diversity and metabolic processes in the ocean. In this Review, we summarize recent developments in our understanding of the ecology, physiology and evolution of protists, derived from transcriptomic studies of cultured strains and natural communities, and discuss how these novel large-scale genetic datasets will be used in the future. © 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.

Published
2017
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14. The Phaeodactylum genome reveals the evolutionary history of diatom genomes

Author

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

15. The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): Illuminating the Functional Diversity of Eukaryotic Life in the Oceans through Transcriptome Sequencing

Author

Keeling, P. J., Burki, F., Wilcox, H. M., Allam, B., Allen, E. E., Amaral-Zettler, L. A., Armbrust, E. V., Archibald, J. M., Bharti, A. K., Bell, C. J., Beszteri, B., Bidle, K. D., Cameron, C. T., Campbell, L., Caron, D. A., Cattolico, R. A., Collier, J. L., Coyne, K., Davy, S. K., Deschamps, P., Dyhrman, S. T., Edvardsen, B., Gates, R. D., Gobler, C. J., Greenwood, S. J., Guida, S. M., Jacobi, J. L., Jakobsen, K. S., James, E. R., Jenkins, B., John, U., Johnson, M. D., Juhl, A. R., Kamp, A., Katz, L. A., Kiene, R., Kudryavtsev, A., Leander, B. S., Lin, S., Lovejoy, C., Lynn, D., Marchetti, A., McManus, G., Nedelcu, A. M., Menden-Deuer, S., Miceli, C., Mock, T., Montresor, M., Moran, M. A., Murray, S., Nadathur, G., Nagai, S., Ngam, P. B., Palenik, B., Pawlowski, J., Petroni, G., Piganeau, G., Posewitz, M. C., Rengefors, K., Romano, G., Rumpho, M. E., Rynearson, T., Schilling, K. B., Schroeder, D. C., Simpson, A. G. B., Slamovits, C. H., Smith, D. R., Smith, G. J., Smith, S. R., Sosik, H. M., Stief, P., Theriot, E., Twary, S. N., Umale, P. E., Vaulot, D., Wawrik, B., Wheeler, G. L., Wilson, W. H., Xu, Y., Zingone, A., Worden, Alexandra Z., Keeling, P. J., Burki, F., Wilcox, H. M., Allam, B., Allen, E. E., Amaral-Zettler, L. A., Armbrust, E. V., Archibald, J. M., Bharti, A. K., Bell, C. J., Beszteri, B., Bidle, K. D., Cameron, C. T., Campbell, L., Caron, D. A., Cattolico, R. A., Collier, J. L., Coyne, K., Davy, S. K., Deschamps, P., Dyhrman, S. T., Edvardsen, B., Gates, R. D., Gobler, C. J., Greenwood, S. J., Guida, S. M., Jacobi, J. L., Jakobsen, K. S., James, E. R., Jenkins, B., John, U., Johnson, M. D., Juhl, A. R., Kamp, A., Katz, L. A., Kiene, R., Kudryavtsev, A., Leander, B. S., Lin, S., Lovejoy, C., Lynn, D., Marchetti, A., McManus, G., Nedelcu, A. M., Menden-Deuer, S., Miceli, C., Mock, T., Montresor, M., Moran, M. A., Murray, S., Nadathur, G., Nagai, S., Ngam, P. B., Palenik, B., Pawlowski, J., Petroni, G., Piganeau, G., Posewitz, M. C., Rengefors, K., Romano, G., Rumpho, M. E., Rynearson, T., Schilling, K. B., Schroeder, D. C., Simpson, A. G. B., Slamovits, C. H., Smith, D. R., Smith, G. J., Smith, S. R., Sosik, H. M., Stief, P., Theriot, E., Twary, S. N., Umale, P. E., Vaulot, D., Wawrik, B., Wheeler, G. L., Wilson, W. H., Xu, Y., Zingone, A., and Worden, Alexandra Z.

Published
2014
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16. Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs

Author

Curtis, B. A., Tanifuji, G., Maruyama, S., Gile, G. H., Hopkins, J. F., Eveleigh, R. J. M., Nakayama, T., Malik, S.-B., Onodera, N. T., Slamovits, C. H., Spencer, D. F., Lane, C. E., Gray, M. W., Archibald, J. M., Burki, F., Hirakawa, Y., Reyes-Prieto, A., Keeling, P. J., Fast, N. M., Green, B. R., Grisdale, C. J., Gruber, A., Kroth, P. G., Irimia, M., Arias, M. C., Ball, S. G., Kuo, A., Schmutz, J., Grimwood, J., Lindquist, E., Lucas, S., Salamov, A., Grigoriev, I. V., Rensing, S. A., Symeonidi, A., Elias, M., Herman, E. K., Klute, M. J., Dacks, J. B., Oborník, M., Kořený, L., Durnford, D. G., Neilson, J. A. D., Armbrust, E. V., Rocap, G., Aves, S. J., Liu, Y., Beiko, R. G., Coutinho, P., Henrissat, B., Hempel, F., Maier, U.G., Zauner, S., Häppner, M. P., Ishida, K.-I., Shirato, S., Suzuki, S., Kim, E., Richards, T. A., Mc Rose, D., Worden, Alexandra Z., Mock, T., Poole, A. M., Pritham, E. J., Roy, S. W., Schaack, S., Bell, C., Bharti, A. K., Crow, J. A., Kramer, R., Mc Fadden, G. I., Curtis, B. A., Tanifuji, G., Maruyama, S., Gile, G. H., Hopkins, J. F., Eveleigh, R. J. M., Nakayama, T., Malik, S.-B., Onodera, N. T., Slamovits, C. H., Spencer, D. F., Lane, C. E., Gray, M. W., Archibald, J. M., Burki, F., Hirakawa, Y., Reyes-Prieto, A., Keeling, P. J., Fast, N. M., Green, B. R., Grisdale, C. J., Gruber, A., Kroth, P. G., Irimia, M., Arias, M. C., Ball, S. G., Kuo, A., Schmutz, J., Grimwood, J., Lindquist, E., Lucas, S., Salamov, A., Grigoriev, I. V., Rensing, S. A., Symeonidi, A., Elias, M., Herman, E. K., Klute, M. J., Dacks, J. B., Oborník, M., Kořený, L., Durnford, D. G., Neilson, J. A. D., Armbrust, E. V., Rocap, G., Aves, S. J., Liu, Y., Beiko, R. G., Coutinho, P., Henrissat, B., Hempel, F., Maier, U.G., Zauner, S., Häppner, M. P., Ishida, K.-I., Shirato, S., Suzuki, S., Kim, E., Richards, T. A., Mc Rose, D., Worden, Alexandra Z., Mock, T., Poole, A. M., Pritham, E. J., Roy, S. W., Schaack, S., Bell, C., Bharti, A. K., Crow, J. A., Kramer, R., and Mc Fadden, G. I.

Abstract

Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote–eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. Both genomes have <21, 000 protein genes and are intron rich, and B. natans exhibits unprecedented alternative splicing for a single-celled organism. Phylogenomic analyses and subcellular targeting predictions reveal extensive genetic and biochemical mosaicism, with both host- and endosymbiont-derived genes servicing the mitochondrion, the host cell cytosol, the plastid and the remnant endosymbiont cytosol of both algae. Mitochondrion-to-nucleus gene transfer still occurs in both organisms but plastid-to-nucleus and nucleomorph-to-nucleus transfers do not, which explains why a small residue of essential genes remains locked in each nucleomorph. © 2012 Macmillan Publishers Limited. All rights reserved.

Published
2012
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17. Phosphate transporters in marine phytoplankton and their viruses: Cross-domain commonalities in viral-host gene exchanges

Author

Monier, A., Welsh, R. M., Gentemann, C., Weinstock, G., Sodergren, E., Armbrust, E. V., Eisen, J. A., Worden, Alexandra Z., Monier, A., Welsh, R. M., Gentemann, C., Weinstock, G., Sodergren, E., Armbrust, E. V., Eisen, J. A., and Worden, Alexandra Z.

Abstract

Phosphate (PO 4) is an important limiting nutrient in marine environments. Marine cyanobacteria scavenge PO 4 using the high-affinity periplasmic phosphate binding protein PstS. The pstS gene has recently been identified in genomes of cyanobacterial viruses as well. Here, we analyse genes encoding transporters in genomes from viruses that infect eukaryotic phytoplankton. We identified inorganic PO 4 transporter-encoding genes from the PHO4 superfamily in several virus genomes, along with other transporter-encoding genes. Homologues of the viral pho4 genes were also identified in genome sequences from the genera that these viruses infect. Genome sequences were available from host genera of all the phytoplankton viruses analysed except the host genus Bathycoccus. Pho4 was recovered from Bathycoccus by sequencing a targeted metagenome from an uncultured Atlantic Ocean population. Phylogenetic reconstruction showed that pho4 genes from pelagophytes, haptophytes and infecting viruses were more closely related to homologues in prasinophytes than to those in what, at the species level, are considered to be closer relatives (e.g. diatoms). We also identified PHO4 superfamily members in ocean metagenomes, including new metagenomes from the Pacific Ocean. The environmental sequences grouped with pelagophytes, haptophytes, prasinophytes and viruses as well as bacteria. The analyses suggest that multiple independent pho4 gene transfer events have occurred between marine viruses and both eukaryotic and bacterial hosts. Additionally, pho4 genes were identified in available genomes from viruses that infect marine eukaryotes but not those that infect terrestrial hosts. Commonalities in marine host-virus gene exchanges indicate that manipulation of host-PO 4 uptake is an important adaptation for viral proliferation in marine systems. Our findings suggest that PO 4-availability may not serve as a simple bottom-up control of marine phytoplankton. © 2011 Society for Applied Microbiolog

Published
2012
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18. Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes Micromonas.

Author

Worden, A. Z., Lee, J.-H., Mock, Thomas, Rouzé, P., Simmson, M. P., Aerts, A. L., Allen, A. E., Cuvelier, M. L., Derelle, E., Everett, M. V., Foulon, E., Grimwood, J., Gundlach, H., Henrissat, B., Napoli, C., McDonald, S. M., Parker, M. S., Rombauts, S., Salamov, A., Badger, J. H., Coutinho, P. M., Demir, E., Dubchak, I., Gentemann, C., Eikrem, W., Gready, J. E., John, Uwe, Lanier, W., Lindquist, E. A., Lucas, S., Mayer, K. F. X., Moreau, H., Not, F., Otillar, R., Panaud, O., Pangilinan, J., Paulsen, I., Piegu, B., Poliakov, A., Robbens, S., Schmutz, J., Toulza, E., Wyss, T., Zelensky, A., Zhou, K., Armbrust, E. V., Bhattacharya, D., Goodenough, U. W., Van de Peer, Y., Grigoriev, I. V., Worden, A. Z., Lee, J.-H., Mock, Thomas, Rouzé, P., Simmson, M. P., Aerts, A. L., Allen, A. E., Cuvelier, M. L., Derelle, E., Everett, M. V., Foulon, E., Grimwood, J., Gundlach, H., Henrissat, B., Napoli, C., McDonald, S. M., Parker, M. S., Rombauts, S., Salamov, A., Badger, J. H., Coutinho, P. M., Demir, E., Dubchak, I., Gentemann, C., Eikrem, W., Gready, J. E., John, Uwe, Lanier, W., Lindquist, E. A., Lucas, S., Mayer, K. F. X., Moreau, H., Not, F., Otillar, R., Panaud, O., Pangilinan, J., Paulsen, I., Piegu, B., Poliakov, A., Robbens, S., Schmutz, J., Toulza, E., Wyss, T., Zelensky, A., Zhou, K., Armbrust, E. V., Bhattacharya, D., Goodenough, U. W., Van de Peer, Y., and Grigoriev, I. V.

Published
2009

19. Green evolution and dynamic adaptations revealed by genomes of the marine picoeukaryotes micromonas

Author

Worden, Alexandra Z., Lee, J.-H., Mock, T., Rouzé, P., Simmons, M. P., Aerts, A. L., Allen, A. E., Cuvelier, M. L., Derelle, E., Everett, M. V., Foulon, E., Grimwood, J., Gundlach, H., Henrissat, B., Napoli, C., McDonald, S. M., Parker, M. S., Rombauts, S., Salamov, A., Von Dassow, P., Badger, J. H., Coutinho, P. M., Demir, E., Dubchak, I., Gentemann, C., Eikrem, W., Gready, J. E., John, U., Lanier, W., Lindquist, E. A., Lucas, S., Mayer, K. F. X., Moreau, H., Not, F., Otillar, R., Panaud, O., Pangilinan, J., Paulsen, I., Piegu, B., Poliakov, A., Robbens, S., Schmutz, J., Toulza, E., Wyss, T., Zelensky, A., Zhou, K., Armbrust, E. V., Bhattacharya, D., Goodenough, U. W., Van De Peer, Y., Grigoriev, I.V., Worden, Alexandra Z., Lee, J.-H., Mock, T., Rouzé, P., Simmons, M. P., Aerts, A. L., Allen, A. E., Cuvelier, M. L., Derelle, E., Everett, M. V., Foulon, E., Grimwood, J., Gundlach, H., Henrissat, B., Napoli, C., McDonald, S. M., Parker, M. S., Rombauts, S., Salamov, A., Von Dassow, P., Badger, J. H., Coutinho, P. M., Demir, E., Dubchak, I., Gentemann, C., Eikrem, W., Gready, J. E., John, U., Lanier, W., Lindquist, E. A., Lucas, S., Mayer, K. F. X., Moreau, H., Not, F., Otillar, R., Panaud, O., Pangilinan, J., Paulsen, I., Piegu, B., Poliakov, A., Robbens, S., Schmutz, J., Toulza, E., Wyss, T., Zelensky, A., Zhou, K., Armbrust, E. V., Bhattacharya, D., Goodenough, U. W., Van De Peer, Y., and Grigoriev, I.V.

Abstract

Picoeukaryotes are a taxonomically diverse group of organism less than 2 micrometers in diameter. Photosynthetic marine picoeukaryotes in the genus Micromonas thrive in ecosystems ranging from tropical to polar and could serve as sentinel organisms for biogeochemical fluxes of modern oceans during climate change. These broadly distributed primary producers belong to an anciently diverged sister clade to land plants. Although Micromonas isolates have high 18S ribosomal RNA gene identity, we found that genomes from two isolates shared only 90 of their predicted genes. Their independent evolutionary paths were emphasized by distinct riboswitch arrangements as well as the discovery of intronic repeat elements in one isolate, and in metagenomic data, but not in other genomes. Divergence appears to have been facilitated by selection and acquisition processes that actively shape the repertoire of genes that are mutually exclusive between the two isolates differently than the core genes. Analyses of the Micromonas genomes offer valuable insights into ecological differentiation and the dynamic nature of early plant evolution.

Published
2009
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20. The Phaeodactylum genome reveals the evolutionary history of diatom genomes

Author

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

21. Analysis of Diatom Blooms Using DNA Fingerprints

Author

WASHINGTON UNIV SEATTLE DEPT OF OCEANOGRAPHY, Armbrust, E V, WASHINGTON UNIV SEATTLE DEPT OF OCEANOGRAPHY, and Armbrust, E V

Abstract

My long-term goals are to understand the interaction between the biological and environmental factors that dictate the timing and magnitude of diatom blooms. I am particularly interested in how species behavior is coupled to environmental conditions and how the extent of genetic and physiological diversity within a population influences its future ability to bloom., The original document contains color images.

Published
2005

23. The genome of the diatom Thalassiosira pseudonana: ecology, evolution, and metabolism

Author

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

25. Diatom acclimation to elevated CO2 via cAMP signalling and coordinated gene expression.

Author

Hennon, Gwenn M. M., Ashworth, Justin, Groussman, Ryan D., Berthiaume, Chris, Morales, Rhonda L., Baliga, Nitin S., Orellana, Mónica V., and Armbrust, E. V.

Subjects
DIATOMS, MARINE productivity, BIOLOGICAL productivity, MARINE ecology, HYDROLYSIS, PHOTOSYNTHESIS, PLANT photorespiration
Abstract

Diatoms are responsible for ∼40% of marine primary productivity, fuelling the oceanic carbon cycle and contributing to natural carbon sequestration in the deep ocean. Diatoms rely on energetically expensive carbon concentrating mechanisms (CCMs) to fix carbon efficiently at modern levels of CO2 (refs , , ). How diatoms may respond over the short and long term to rising atmospheric CO2 remains an open question. Here we use nitrate-limited chemostats to show that the model diatom Thalassiosira pseudonana rapidly responds to increasing CO2 by differentially expressing gene clusters that regulate transcription and chromosome folding, and subsequently reduces transcription of photosynthesis and respiration gene clusters under steady-state elevated CO2. These results suggest that exposure to elevated CO2 first causes a shift in regulation, and then a metabolic rearrangement. Genes in one CO2-responsive cluster included CCM and photorespiration genes that share a putative cAMP-responsive cis-regulatory sequence, implying these genes are co-regulated in response to CO2, with cAMP as an intermediate messenger. We verified cAMP-induced downregulation of CCM gene δ-CA3 in nutrient-replete diatom cultures by inhibiting the hydrolysis of cAMP. These results indicate an important role for cAMP in downregulating CCM and photorespiration genes under elevated CO2 and provide insights into mechanisms of diatom acclimation in response to climate change. [ABSTRACT FROM AUTHOR]

Published
2015
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28. Diatom acclimation to elevated CO2via cAMP signalling and coordinated gene expression

Author

Hennon, Gwenn M. M., Ashworth, Justin, Groussman, Ryan D., Berthiaume, Chris, Morales, Rhonda L., Baliga, Nitin S., Orellana, Mónica V., and Armbrust, E. V.

Abstract

Diatoms are responsible for ~40% of marine primary productivity, fuelling the oceanic carbon cycle and contributing to natural carbon sequestration in the deep ocean. Diatoms rely on energetically expensive carbon concentrating mechanisms (CCMs) to fix carbon efficiently at modern levels of CO2(refs , , ). How diatoms may respond over the short and long term to rising atmospheric CO2remains an open question. Here we use nitrate-limited chemostats to show that the model diatom Thalassiosira pseudonana rapidly responds to increasing CO2by differentially expressing gene clusters that regulate transcription and chromosome folding, and subsequently reduces transcription of photosynthesis and respiration gene clusters under steady-state elevated CO2. These results suggest that exposure to elevated CO2first causes a shift in regulation, and then a metabolic rearrangement. Genes in one CO2-responsive cluster included CCM and photorespiration genes that share a putative cAMP-responsive cis-regulatory sequence, implying these genes are co-regulated in response to CO2, with cAMP as an intermediate messenger. We verified cAMP-induced downregulation of CCM gene d-CA3 in nutrient-replete diatom cultures by inhibiting the hydrolysis of cAMP. These results indicate an important role for cAMP in downregulating CCM and photorespiration genes under elevated CO2and provide insights into mechanisms of diatom acclimation in response to climate change.

Published
2015
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31. COMPARATIVE GENOMICS OF MARINE PHYTOPLANKTON.

Author

Armbrust, E. V.

Subjects
*MARINE phytoplankton
Abstract

An abstract of the article "Comparative Genomics of Marine Phytoplankton," by E. V. Armbrust is presented.

Published
2009

32. Genetic diversity of attached bacteria in the hindgut of the deposit-feeding shrimp Neotrypaea (formerly Callianassa) californiensis (decapoda: thalassinidae).

Author

Lau WW, Jumars PA, and Armbrust EV

Subjects
Animals, DNA, Ribosomal genetics, Diet, Digestive System microbiology, Genes, Bacterial genetics, Genetic Variation, Phylogeny, Polymerase Chain Reaction, RNA, Ribosomal, 16S genetics, Bacteria genetics, Bacteria isolation & purification, Decapoda microbiology
Abstract

Microbial colonization of marine invertebrate guts is widespread, but in general the roles that these bacteria play in the nutrition of their hosts are unknown. To examine the diversity and potential nutritional roles of hindgut microbiota in a deposit feeder, PCR-amplified 16S rRNA genes were cloned from the bacterial community attached to the hindguts of the thalassinid shrimp Neotrypaea californiensis exposed to different feeding treatments. Partial 16S rDNA sequences were analyzed for 30 clones for three shrimp per treatment for a total of 270 clones. No effects of host starvation or high-protein diets were apparent on hindgut bacterial community composition. Diversity analyses indicated high variability between bacterial communities in individual shrimp hindguts, but partial 16S rDNA sequences revealed remarkable species-level similarity (>98%) within clusters of sequences from the different shrimp hindguts, and many sequences from different shrimp hindguts were identical. Sequences belonged to three main groups of bacteria: Cytophaga-Flavobacteria-Bacteroides (CFB), proteobacteria, and gram-positives. Of the 270 sequences, 40% belonged to the alpha-proteobacteria, > or = 5% each to the gamma- and epsilon -proteobacteria, and > or =20% each to the gram-positive and CFB groups. All except one sequence are novel with < or = 95% sequence similarity to known genes. Despite weak similarity to known taxa,about 75% of the sequences were most closely related to known symbiotic and sedimentary bacteria. The bacteria in shrimp hindguts represent new species that have not yet been en-countered in other environments, and gut environments may be a rich source of the difficult-to-culture and novel components of marine bacterial diversity.

Published
2002
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33. Rapid evolution of a sexual reproduction gene in centric diatoms of the genus Thalassiosira.

Author

Armbrust EV and Galindo HM

Subjects
Amino Acid Sequence, Base Sequence, DNA, Complementary genetics, Diatoms classification, Genes, rRNA genetics, Molecular Sequence Data, Phylogeny, Polymorphism, Single-Stranded Conformational, Proteins chemistry, Protozoan Proteins, RNA, Ribosomal, 18S genetics, Reproduction genetics, Reproduction physiology, Tubulin genetics, Diatoms genetics, Diatoms physiology, Evolution, Molecular, Proteins genetics
Abstract

Sexual reproduction is commonly assumed to occur in the vast majority of diatoms due to the intimate association of this process with cell size control. Surprisingly, however, little is known about the impact of sexual events on diatom population dynamics. The Sig1 gene is strongly upregulated during sexual reproduction in the centric diatom Thalassiosira weissflogii and has been hypothesized to encode a protein involved in gamete recognition. In the present study, degenerate PCR primers were designed and used to amplify a portion of Sig1 from three closely related species in the cosmopolitan genus Thalassiosira, Thalassiosira oceanica, Thalassiosira guillardii, and Thalassiosira pseudonana. Identification of Sig1 in these three additional species facilitated development of this gene as a molecular marker for diatom sexual events. Examination of the new sequences indicated that multiple copies of Sig1 are probably present in the genome. Moreover, compared to the housekeeping gene beta-tubulin, the Sig1 genes of isolates of T. weissflogii collected from different regions of the Atlantic and Pacific oceans displayed high levels of divergence. The Sig1 genes of the four closely related Thalassiosira species also displayed high levels of sequence divergence compared to the levels observed with a second gene, Fcp, probably explaining why Sig1 could not be amplified from more distantly related species. The high levels of sequence divergence both within and between species suggest that Sig1 is rapidly evolving in a manner reminiscent of the manner observed in other genes that encode gamete recognition proteins. A simple model is presented for Sig1 evolution and the implications of such a rapidly evolving sexual reproduction gene for diatom speciation and population dynamics.

Published
2001
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34. Identification of a new gene family expressed during the onset of sexual reproduction in the centric diatom Thalassiosira weissflogii.

Author

Armbrust EV

Subjects
Amino Acid Sequence, Cloning, Molecular, DNA chemistry, DNA genetics, DNA, Complementary, Diatoms physiology, Gene Expression Regulation, Genes, Molecular Sequence Data, Proteins chemistry, Proteins metabolism, Reproduction, Reverse Transcriptase Polymerase Chain Reaction methods, Sequence Alignment, Sequence Analysis, DNA, Diatoms genetics, Proteins genetics, Protozoan Proteins
Abstract

An intriguing feature of the diatom life cycle is that sexual reproduction and the generation of genetic diversity are coupled to the control of cell size. A PCR-based cDNA subtraction technique was used to identify genes that are expressed as small cells of the centric diatom Thalassiosira weissflogii initiate gametogenesis. Ten genes that are up-regulated during the early stages of sexual reproduction have been identified thus far. Three of the sexually induced genes, Sig1, Sig2, and Sig3, were sequenced to completion and are members of a novel gene family. The three polypeptides encoded by these genes possess different molecular masses and charges but display many features in common: they share five highly conserved domains; they each contain three or more cysteine-rich epithelial growth factor (EGF)-like repeats; and they each display homology to the EGF-like region of the vertebrate extracellular matrix glycoprotein tenascin X. Interestingly, the five conserved domains appear in the same order in each polypeptide but are separated by variable numbers of nonconserved amino acids. SIG1 and SIG2 display putative regulatory domains within the nonconserved regions. A calcium-binding, EF-hand motif is found in SIG1, and an ATP/GTP binding motif is present in SIG2. The striking similarity between the SIG polypeptides and extracellular matrix components commonly involved in cell-cell interactions suggests that the SIG polypeptides may play a role in sperm-egg recognition. The SIG polypeptides are thus important molecular targets for determining when and where sexual reproduction occurs in the field.

Published
1999
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35. Phylogenetic analysis of particle-attached and free-living bacterial communities in the Columbia river, its estuary, and the adjacent coastal ocean.

Author

Crump BC, Armbrust EV, and Baross JA

Subjects
Bacteria classification, Bacteria genetics, DNA, Bacterial chemistry, DNA, Bacterial genetics, Fresh Water microbiology, Molecular Sequence Data, Oregon, Polymorphism, Restriction Fragment Length, RNA, Ribosomal, 16S genetics, Seawater microbiology, Sequence Analysis, DNA, Washington, Bacteria isolation & purification, Phylogeny, Water Microbiology
Abstract

The Columbia River estuary is a dynamic system in which estuarine turbidity maxima trap and extend the residence time of particles and particle-attached bacteria over those of the water and free-living bacteria. Particle-attached bacteria dominate bacterial activity in the estuary and are an important part of the estuarine food web. PCR-amplified 16S rRNA genes from particle-attached and free-living bacteria in the Columbia River, its estuary, and the adjacent coastal ocean were cloned, and 239 partial sequences were determined. A wide diversity was observed at the species level within at least six different bacterial phyla, including most subphyla of the class Proteobacteria. In the estuary, most particle-attached bacterial clones (75%) were related to members of the genus Cytophaga or of the alpha, gamma, or delta subclass of the class Proteobacteria. These same clones, however, were rare in or absent from either the particle-attached or the free-living bacterial communities of the river and the coastal ocean. In contrast, about half (48%) of the free-living estuarine bacterial clones were similar to clones from the river or the coastal ocean. These free-living bacteria were related to groups of cosmopolitan freshwater bacteria (beta-proteobacteria, gram-positive bacteria, and Verrucomicrobium spp.) and groups of marine organisms (gram-positive bacteria and alpha-proteobacteria [SAR11 and Rhodobacter spp.]). These results suggest that rapidly growing particle-attached bacteria develop into a uniquely adapted estuarine community and that free-living estuarine bacteria are similar to members of the river and the coastal ocean microbial communities. The high degree of diversity in the estuary is the result of the mixing of bacterial communities from the river, estuary, and coastal ocean.

Published
1999
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36. A mating type-linked gene cluster expressed in Chlamydomonas zygotes participates in the uniparental inheritance of the chloroplast genome.

Author

Armbrust EV, Ferris PJ, and Goodenough UW

Subjects
Amino Acid Sequence, Animals, Blotting, Western, Chlamydomonas reinhardtii physiology, Cloning, Molecular, Crosses, Genetic, Genes, Fungal, Genes, Mating Type, Fungal, Molecular Sequence Data, Protozoan Proteins biosynthesis, Restriction Mapping, Chlamydomonas reinhardtii genetics, Chloroplasts physiology, Multigene Family, Protozoan Proteins genetics, Zygote physiology
Abstract

A characteristic feature of early zygote development in Chlamydomonas is the selective degradation of chloroplast DNA from the mating type minus parent. The zygote-specific gene cluster ezy-1 is linked to the mating type locus and is transcribed almost immediately upon zygote formation. We show here that the acidic Ezy-1 polypeptide is rapidly transported to both the plus and minus chloroplasts, where it interacts with each chloroplast nucleoid. Expression of ezy-1 is selectively inhibited when plus, but not minus, gametes are briefly ultraviolet irradiated just prior to mating, a treatment known to disrupt the uniparental inheritance of chloroplast traits. We propose that the Ezy-1 polypeptide participates in the destruction of the minus chloroplast DNA in zygotes and thus the uniparental inheritance of chloroplast traits. The ezy-1 gene represents a valuable molecular probe for dissecting mechanisms underlying organelle inheritance.

Published
1993
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