Telonemia, a new protist phylum with affinity to chromist lineages

被引:72
作者
Shalchian-Tabrizi, K.
Eikrem, W.
Klaveness, D.
Vaulot, D.
Minge, M. A.
Le Gall, F.
Romari, K.
Throndsen, J.
Botnen, A.
Massana, R.
Thomsen, H. A.
Jakobsen, K. S. [1 ]
机构
[1] Univ Oslo, Ctr Ecol & Evolutionary Synth, N-0316 Oslo, Norway
[2] Univ Oslo, Program Plankton Biol, Dept Biol, N-0316 Oslo, Norway
[3] CNRS, UMR 7127, Stn Biol, F-29682 Roscoff, France
[4] Univ Paris 06, F-29682 Roscoff, France
[5] Univ Oslo, Sci Comp Grp, Ctr Informat Technol, N-0316 Oslo, Norway
[6] CMIMA, Inst Ciencias Mar, Catalonia 08003, Spain
[7] Danish Inst Fisheries Res, Dept Marine Ecol & Aquaculture, DK-2920 Charlottenlund, Denmark
关键词
Telonema; Telonemia; environmental sequences; phylogeny; covarion substitution pattern;
D O I
10.1098/rspb.2006.3515
中图分类号
Q [生物科学];
学科分类号
07 ; 0710 ; 09 ;
摘要
Recent molecular investigations of marine samples taken from different environments, including tropical, temperate and polar areas, as well as deep thermal vents, have revealed an unexpectedly high diversity of protists, some of them forming deep-branching clades within important lineages, such as the alveolates and heterokonts. Using the same approach on coastal samples, we have identified a novel group of protist small subunit (SSU) rDNA sequences that do not correspond to any phylogenetic group previously identified. Comparison with other sequences obtained from cultures of heterotrophic protists showed that the environmental sequences grouped together with Telonema, a genus known since 1913 but of uncertain taxonomic affinity. Phylogenetic analyses using four genes (SSU, Hsp90, alpha-tubulin and beta-tubulin), and accounting for gamma- and covarion-distributed substitution rates, revealed Telonema as a distinct group of species branching off close to chromist lineages. Consistent with these gene trees, Telonema possesses ultrastructures revealing both the distinctness of the group and the evolutionary affinity to chromist groups. Altogether, the data suggest that Telonema constitutes a new eukaryotic phylum, here defined as Telonemia, possibly representing a key clade for the understanding of the early evolution of bikont protist groups, such as the proposed chromalveolate supergroup.
引用
收藏
页码:1833 / 1842
页数:10
相关论文
共 53 条
[1]   Biology and systematics of heterokont and haptophyte algae [J].
Andersen, RA .
AMERICAN JOURNAL OF BOTANY, 2004, 91 (10) :1508-1522
[2]   Chlorophyll c-containing plastid relationships based on analyses of a multigene data set with all four chromalveolate lineages [J].
Bachvaroff, TR ;
Puerta, MVS ;
Delwiche, CF .
MOLECULAR BIOLOGY AND EVOLUTION, 2005, 22 (09) :1772-1782
[3]   A kingdom-level phylogeny of eukaryotes based on combined protein data [J].
Baldauf, SL ;
Roger, AJ ;
Wenk-Siefert, I ;
Doolittle, WF .
SCIENCE, 2000, 290 (5493) :972-977
[4]   How many novel eukaryotic 'kingdoms'? Pitfalls and limitations of environmental DNA surveys [J].
Berney, Cedric ;
Fahrni, Jose ;
Pawlowski, Jan .
BMC BIOLOGY, 2004, 2 (1)
[5]  
Brown R.M., 1976, APPL POLYM S, V28, P537
[6]   The phagotrophic origin of eukaryotes and phylogenetic classification of protozoa [J].
Cavalier-Smith, T .
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 2002, 52 :297-354
[7]   Principles of protein and lipid targeting in secondary symbiogenesis: Euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree [J].
Cavalier-Smith, T .
JOURNAL OF EUKARYOTIC MICROBIOLOGY, 1999, 46 (04) :347-366
[8]   Only six kingdoms of life [J].
Cavalier-Smith, T .
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES, 2004, 271 (1545) :1251-1262
[9]   Protist phylogeny and the high-level classification of Protozoa [J].
Cavalier-Smith, T .
EUROPEAN JOURNAL OF PROTISTOLOGY, 2003, 39 (04) :338-348
[10]  
Cavalier-Smith Thomas, 2004, Systematics Association Special Volume Series, V68, P75