Telonemia

Telonemia is a phylum of microscopic eukaryote, single-celled organisms.[1] They were formerly classified as protists until that kingdom fell out of general use, and are suggested to have evolutionary significance in being a possible transitional form between ecologically important heterotrophic and photosynthetic species among chromalveolates.[2][3]

Telonemia
Scientific classification
Clade: TSAR
Phylum: Telonemia
Genera

One paper places them in the SAR supergroup.[4] Phylogenomic analyses of 127 genes place Telonemia with Centroheliozoa in a group also consisting of cryptomonads and haptophytes[5] (see Cryptomonads-haptophytes assemblage).

Although they have been studied in primarily marine environments, they have also been found in freshwater.[6][7]

Shalchian-Tabrizi et al say that 18S rDNA sequences in the phylum formed two major groups, Group 1 and 2, including T. subtilis and T. antarcticum respectively, and that these were further sub-divided into several statistically supported clades of sequences with restricted geographic distribution. Species of Telonemia are heterotrophic predators, feeding on a wide range of bacteria and pico- to nano-sized phytoplankton. Chloroplasts have not been observed in any of the investigated species.[8] By using specific PCR primers, they revealed a much larger diversity of Telonemia from environmental samples than previously uncovered by eukaryote-wide primers. They are globally distributed in marine waters and are frequently encountered in environmental clone libraries. The evolutionary origin of Telonemia was inferred from phylogenetic reconstruction of single- and concatenated sequences obtained from both cultured strains and environmental clones.[2]

Pawlowski identifies it as a micro-kingdom.[9] It is considered sister of the SAR group.[10]

Species

Although only two species have been described formally,[11] DNA sequences collected from seawater suggest there are many more species which have not yet been described.[12]

  • Class Telonemea Cavalier-Smith 1993[13] [Telonemia Shalchian-Tabrizi 2006]
    • Order Telonemida Cavalier-Smith 1993
      • Family Telonemidae Cavalier-Smith 1993
        • Genera Lateronema Cavalier-Smith 2015
          • Species Lateronema antarctica (Thomsen 2005) Cavalier-Smith 2015 [Telonema antarctica Thomsen 1992]
        • Genera Telonema Griessmann 1913
          • Species Telonema subtile Griessmann 1913 [Telonema subtilis Griessmann, 1913[14]]

History

The genus Telonema was described in 1913 by Griessmann.[15]

References
  1. Vogt, Yngve (February 1, 2012). "Found Unknown Group of Oceanic Life Forms". Apollon.
  2. 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 (28 April 2006). "Telonemia, a new protist phylum with affinity to chromist lineages". Proceedings of the Royal Society B: Biological Sciences. 273 (1595): 1833–1842. doi:10.1098/rspb.2006.3515. PMC 1634789. PMID 16790418.
  3. "The early evolution of the eukaryotic cell addressed by chloroplast biology, multigene phylogenies and the new phylum Telonemia". Archived from the original on 2007-02-23. Retrieved 2007-02-23.
  4. Reeb, Valérie C.; Peglar, Michael T.; Yoon, Hwan Su; Bai, Jennifer Ruoyu; Wu, Min; Shiu, Philip; Grafenberg, Jessie L.; Reyes-Prieto, Adrian; Rümmele, Susanne E.; Gross, Jeferson; Bhattacharya, D (October 2009). "Interrelationships of chromalveolates within a broadly sampled tree of photosynthetic protists". Molecular Phylogenetics and Evolution. 53 (1): 202–211. doi:10.1016/j.ympev.2009.04.012. PMID 19398025.
  5. Burki, Fabien; Inagaki, Yuji; Bråte, Jon; Archibald, John M.; Keeling, Patrick J.; Cavalier-Smith, Thomas; Sakaguchi, Miako; Hashimoto, Tetsuo; Horak, Ales; Kumar, Surendra; Klaveness, Dag; Jakobsen, Kjetill S.; Pawlowski, Jan; Shalchian-Tabrizi, Kamran (2009). "Large-Scale Phylogenomic Analyses Reveal That Two Enigmatic Protist Lineages, Telonemia and Centroheliozoa, Are Related to Photosynthetic Chromalveolates". Genome Biology and Evolution. 1: 231–238. doi:10.1093/gbe/evp022. PMC 2817417. PMID 20333193.
  6. Lefèvre, Emilie; Roussel, Balbine; Amblard, Christian; Sime-Ngando, Télesphore; Ibelings, Bas (11 June 2008). "The Molecular Diversity of Freshwater Picoeukaryotes Reveals High Occurrence of Putative Parasitoids in the Plankton". PLOS ONE. 3 (6): e2324. Bibcode:2008PLoSO...3.2324L. doi:10.1371/journal.pone.0002324. PMC 2396521. PMID 18545660.
  7. Bråte, Jon; Klaveness, Dag; Rygh, Tellef; Jakobsen, Kjetill S; Shalchian-Tabrizi, Kamran (2010). "Telonemia-specific environmental 18S rDNA PCR reveals unknown diversity and multiple marine-freshwater colonizations". BMC Microbiology. 10 (1): 168. doi:10.1186/1471-2180-10-168. PMC 2891722. PMID 20534135.
  8. 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 (22 July 2006). "Telonemia, a new protist phylum with affinity to chromist lineages". Proceedings of the Royal Society B: Biological Sciences. 273 (1595): 1833–1842. doi:10.1098/rspb.2006.3515. PMC 1634789. PMID 16790418.
  9. Pawlowski, Jan (15 April 2013). "The new micro-kingdoms of eukaryotes". BMC Biology. 11: 40. doi:10.1186/1741-7007-11-40. PMC 3626909. PMID 23587248.
  10. Strassert, Jürgen F H; Jamy, Mahwash; Mylnikov, Alexander P; Tikhonenkov, Denis V; Burki, Fabien; Shapiro, Beth (April 2019). "New Phylogenomic Analysis of the Enigmatic Phylum Telonemia Further Resolves the Eukaryote Tree of Life". Molecular Biology and Evolution. 36 (4): 757–765. doi:10.1093/molbev/msz012. PMC 6844682. PMID 30668767.
  11. Strassert, Jürgen F H; Jamy, Mahwash; Mylnikov, Alexander P; Tikhonenkov, Denis V; Burki, Fabien; Shapiro, Beth (April 2019). "New Phylogenomic Analysis of the Enigmatic Phylum Telonemia Further Resolves the Eukaryote Tree of Life". Molecular Biology and Evolution. 36 (4): 757–765. doi:10.1093/molbev/msz012. PMC 6844682. PMID 30668767.
  12. Shalchian-Tabrizi, K; Kauserud, H; Massana, R; Klaveness, D; Jakobsen, KS (18 April 2007). "Analysis of Environmental 18S Ribosomal RNA Sequences reveals Unknown Diversity of the Cosmopolitan Phylum Telonemia". Protist. 158 (2): 173–180. doi:10.1016/j.protis.2006.10.003. PMID 17196879.
  13. Cavalier-Smith, Thomas; Chao, Ema E.; Lewis, Rhodri (December 2015). "Multiple origins of Heliozoa from flagellate ancestors: New cryptist subphylum Corbihelia, superclass Corbistoma, and monophyly of Haptista, Cryptista, Hacrobia and Chromista". Molecular Phylogenetics and Evolution. 93: 331–362. doi:10.1016/j.ympev.2015.07.004. PMID 26234272.
  14. "European Marine Biodiversity Research Sites". MarBEF. Flanders Marine Institute. 2004.
  15. Grießmann, Karl (1913). Über marine Flagellaten [About marine flagellates] (Thesis) (in German). Fischer. OCLC 638176877.
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