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
        • Genera Lateronema Cavalier-Smith 2015
          • Species Lateronema antarctica (Thomsen 2005) Cavalier-Smith 2015 [Telonema antarctica Thomsen 1992]
        • Genera Telonema Greissmann 1913
          • Species Telonema subtile Greissmann 1913 [Telonema subtilis Griessmann, 1913[14]]

History

This genus was described in 1913 by Griessmann.[15]

References
  1. "Archived copy". Archived from the original on 2007-01-09. Retrieved 2007-01-02.CS1 maint: archived copy as title (link)
  2. Shalchian-Tabrizi K, Eikrem W, Klaveness D, Vaulot D, Minge M, Le Gall F, Romari K, Throndsen J, Botnen A, Massana R, Thomsen H, Jakobsen K (2006). "Telonemia, a new protist phylum with affinity to chromist lineages". Proc Biol Sci. 273 (1595): 1833–42. doi:10.1098/rspb.2006.3515. PMC 1634789. PMID 16790418.CS1 maint: multiple names: authors list (link)
  3. "Archived copy". Archived from the original on 2007-02-23. Retrieved 2007-02-23.CS1 maint: archived copy as title (link)
  4. Reeb, Vc; Peglar, Mt; Yoon, Hs; Bai, Jr; Wu, M; Siu, P; Grafenberg, Jl; Reyes-Prieto, A; Rümmele, Se; Gross, J; Bhattacharya, D (May 2009). "Interrelationships of chromalveolates within a broadly sampled tree of photosynthetic protists". Molecular Phylogenetics & Evolution. 53 (1): 202–11. doi:10.1016/j.ympev.2009.04.012. ISSN 1055-7903. PMID 19398025.
  5. Burki, F; Inagaki, Y; Bråte, J; Archibald, J.; Keeling, P.; Cavalier-Smith, T; Sakaguchi, M; Hashimoto, T; Horak, A; Kumar, S; Klaveness, D; Jakobsen, K.S; Pawlowski, J; Shalchian-Tabrizi, K (2009). "Large-Scale Phylogenomic Analyses Reveal That Two Enigmatic Protist Lineages, Telonemia and Centroheliozoa, Are Related to Photosynthetic Chromalveolates". Genome Biology and Evolution. 1: 231–8. doi:10.1093/gbe/evp022. PMC 2817417. PMID 20333193. Archived from the original (Free full text) on 2012-07-10.
  6. Lefèvre, E; Roussel, B; Amblard, C; Sime-Ngando, T (Jun 2008). Ibelings, Bas (ed.). "The Molecular Diversity of Freshwater Picoeukaryotes Reveals High Occurrence of Putative Parasitoids in the Plankton". PLoS ONE. 3 (6): e2324. doi:10.1371/journal.pone.0002324. PMC 2396521. PMID 18545660.CS1 maint: multiple names: authors list (link)
  7. Bråte, J; Klaveness, D; Rygh, T; Jakobsen, K.S; Shalchian-Tabrizi, K (Jun 2010). "Telonemia-specific environmental 18S rDNA PCR reveals unknown diversity and multiple marine-freshwater colonizations". BMC Microbiology. 10: 168. doi:10.1186/1471-2180-10-168. PMC 2891722. PMID 20534135.
  8. Telonemia, a new protist phylum with affinity to chromist lineages - NCBI
  9. Pawlowski, Jan. 2013. The new micro-kingdoms of eukaryotes. BMC Biology 11: 40-42. (reearchgate.net; europepmc.org)
  10. Strassert, Jürgen F. H.; Jamy, Mahwash; Mylnikov, Alexander P.; Tikhonenkov, Denis V.; Burki, Fabien (2019-04-01). "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. ISSN 0737-4038. PMC 6844682. PMID 30668767.
  11. Dag Klaveness1, Shalchian-Tabrizi, K; Thomsen, H.A.; Eikrem, W; Jakobsen, K.S (2005). "Telonema antarcticum sp. nov., a common marine phagotrophic flagellate". Int J Syst Evol Microbiol. 55 (6): 2595–2604. doi:10.1099/ijs.0.63652-0. PMID 16280533.CS1 maint: multiple names: authors list (link)
  12. Shalchian-Tabrizi, K; Kauserud, H; Massana, R; Klaveness, D; Jakobsen, Ks (Apr 2007). "Analysis of environmental 18S ribosomal RNA sequences reveals unknown diversity of the cosmopolitan phylum Telonemia". Protist. 158 (2): 173–80. doi:10.1016/j.protis.2006.10.003. ISSN 1434-4610. PMID 17196879.
  13. Cavalier-Smith; Chao; Lewis (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 K (1913) Über marine Flagellaten. Arch Protistenk 32:1–78
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