1887

International Journal of Systematic and Evolutionary Microbiology

Volume 53, Issue 6

Cytoskeletal organization, phylogenetic affinities and systematics in the contentious taxon Excavata (Eukaryota) Free

Abstract

An overview of the controversial proposal for the major eukaryote taxon ‘Excavata’ is presented. Excavata is predicted to include at least ten distinct groups: jakobids, , , , retortamonads, diplomonads, Heterolobosea, oxymonads, parabasalids and Euglenozoa. These ‘excavates' have broadly similar flagellar apparatus organizations, for which a ‘universal’ terminology is provided. Most, but not all, of these organisms share a distinctive suspension-feeding groove, as well as some or all of a set of seven other proposed cytoskeletal apomorphies. Cladistic analyses of morphological data do not resolve high-level relationships within Excavata. Excavate-rich molecular phylogenies recover some robust clades, but do not support or strongly refute the monophyly of Excavata. A partial classification for excavates is presented, with phylogenetic diagnoses for Excavata and for two novel taxon names, Fornicata (, retortamonads, diplomonads) and Preaxostyla (, oxymonads).

  • Published Online:
Keyword(s): R1–R4, roots 1–4 , SSU, small-subunit and TBR, tree bisection–reconnection
SGM
Loading

Article metrics loading...

/content/journal/ijsem/10.1099/ijs.0.02578-0
2003-11-01
2021-07-27
Loading full text...

Full text loading...

/deliver/fulltext/ijsem/53/6/ijs531759.html?itemId=/content/journal/ijsem/10.1099/ijs.0.02578-0&mimeType=html&fmt=ahah

References

  1. Archibald J. M., O'Kelly C. J., Doolittle W. F. 2002; The chaperonin genes of jakobid and jakobid-like flagellates: implications for eukaryotic evolution. Mol Biol Evol 19:422–431 [CrossRef]
     [Google Scholar]
  2. Balamuth W., Bradbury P. C., Schuster F. L. 1983; Ultrastructure of the amoeboflagellate Tetramitus rostratus . J Protozool 30:445–455 [CrossRef]
     [Google Scholar]
  3. Baldauf S. L., Roger A. J., Wenk-Siefert I., Doolittle W. F. 2000; A kingdom-level phylogeny of eukaryotes based on combined protein data. Science 290:972–977 [CrossRef]
     [Google Scholar]
  4. Bernard C., Simpson A. G. B., Patterson D. J. 1997; An ultrastructural study of a free-living retortamonad, Chilomastix cuspidata (Larsen and Patterson 1990 n. comb. (Retortamonadida Protista). Eur J Protistol 33:254–265 [CrossRef]
     [Google Scholar]
  5. Bernard C., Simpson A. G. B., Patterson D. J. 2000; Some free-living flagellates (Protista) from anoxic habitats. Ophelia 52:113–142 [CrossRef]
     [Google Scholar]
  6. Broers C. A. M., Stumm C. K., Vogels G. D., Brugerolle G. 1990; Psalteriomonas lanterna gen. nov. sp. nov. a free-living amoeboflagellate isolated from freshwater anaerobic sediments. Eur J Protistol 25:369–380 [CrossRef]
     [Google Scholar]
  7. Broers C. A. M., Meijers H. H. M., Symens J. C., Stumm C. K., Vogels G. D., Brugerolle G. 1993; Symbiotic association of Psalteriomonas vulgaris n. spec. with Methanobacterium formicicum . Eur J Protistol 29:98–105 [CrossRef]
     [Google Scholar]
  8. Brugerolle G. 1970; Sur l'ultrastructure et la position systématique de Pyrsonympha vertens (Zooflagellata, Pyrsonymphina. C R Acad Sci (Paris) 270:966–969 in French
    [Google Scholar]
  9. Brugerolle G. 1973; Etude ultrastructurale du trophozoite et du kyste chez le genre Chilomastix Aléxéieff, 1910 (Zoomastigophorea, Retortamonadida Grassé1952. J Protozool 20:574–585 in French [CrossRef]
     [Google Scholar]
  10. Brugerolle G. 1975a; Etude ultrastructurale du genre Enteromonas da Fonseca (Zoomastigophorea) et révision de l'ordre des Diplomonadida Wenyon. J Protozool 22:468–475 in French [CrossRef]
     [Google Scholar]
  11. Brugerolle G. 1975b; Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa, Dangeard 1910. V. Nouvelle interprétation de l'organisation cellulaire de Giardia . Protistologica 11:99–109 in French
    [Google Scholar]
  12. Brugerolle G. 1975c; Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa, Dangeard 1910). VI. Caractères généraux des diplozoaires. Protistologica 11:111–118 in French
    [Google Scholar]
  13. Brugerolle G. 1977; Ultrastructure du genre Retortamonas Grassi 1879 (Zoomastigophorea, Retortamonadida Wenrich 1931. Protistologica 13:233–240 in French
    [Google Scholar]
  14. Brugerolle G. 1991a; Flagellar and cytoskeletal systems in amitochondrial flagellates: Archamoeba, Metamonada and Parabasala. Protoplasma 164:70–90 [CrossRef]
     [Google Scholar]
  15. Brugerolle G. 1991b; Cell organization in free-living amitochondriate heterotrophic flagellates. In The Biology of Free-Living Heterotrophic Flagellates pp 133–148Edited by Patterson D. J., Larsen J. Oxford: Clarendon Press;
     [Google Scholar]
  16. Brugerolle G. 1992; Flagellar apparatus duplication and partition, flagellar transformation during division in Entosiphon sulcatum . Biosystems 28:203–209 [CrossRef]
     [Google Scholar]
  17. Brugerolle G., Taylor F. J. R. 1977; Taxonomy, cytology and evolution of the Mastigophora. In Proceedings of the 5th International Congress of Protozoology pp 14–28Edited by Hutner S. H. New York: Society of Protozoologists;
     [Google Scholar]
  18. Brugerolle G., Patterson D. J. 1997; Ultrastructure of Trimastix convexa Hollande, an amitochondriate anaerobic flagellate with a previously undescribed organisation. Eur J Protistol 33:121–130 [CrossRef]
     [Google Scholar]
  19. Brugerolle G., Lee J. J. 2000a; Order Oxymonadida. In The Illustrated Guide to the Protozoa, 2nd edn. pp 1186–1195Edited by Lee J. J., Leedale G. F., Bradbury P. Lawrence, KS: Society of Protozoologists;
     [Google Scholar]
  20. Brugerolle G., Lee J. J. 2000b; Phylum Parabasalia. In The Illustrated Guide to the Protozoa, 2nd edn. pp 1196–1249Edited by Lee J. J., Leedale G. F., Bradbury P. Lawrence, KS: Society of Protozoologists;
     [Google Scholar]
  21. Brugerolle G., Müller M. 2000; Amitochondriate flagellates. In Flagellates: Unity, Diversity and Evolution pp 166–189Edited by Green J. C., Leadbeater B. S. C. London: Taylor & Francis;
     [Google Scholar]
  22. Brugerolle G., Regnault J.-P. 2001; Ultrastructure of the enteromonad flagellate Caviomonas mobilis . Parasitol Res 87:662–665 [CrossRef]
     [Google Scholar]
  23. Brugerolle G., Joyon L., Öktem N. 1973a; Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa Dangeard 1910. I. Étude ultrastructurale du genre Trepomonas (Dujardin). Protistologica 9:339–348 in French
    [Google Scholar]
  24. Brugerolle G., Joyon L., Öktem N. 1973b; Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa Dangeard 1910. II. Étude ultrastructurale du genre Spironucleus (Lavier 1936). Protistologica 9:495–502 in French
    [Google Scholar]
  25. Brugerolle G., Joyon L., Öktem N. 1974; Contribution a l'étude cytologique et phylétique des diplozoaires (Zoomastigophorea, Diplozoa Dangeard 1910. IV. Étude ultrastructurale du genre Octomitus (Prowazek 1904). Protistologica 10:457–463 in French
    [Google Scholar]
  26. Brugerolle G., Kunstyr I., Senaud J., Friedhoff K. T. 1980; Fine structure of trophozoites and cysts of the pathogenic diplomonad Spironucleus muris . Z Parasitenkd 62:47–61 [CrossRef]
     [Google Scholar]
  27. Brugerolle G., Bricheux G., Philippe H., Coffe G. 2002; Collodictyon triciliatum and Diphylleia rotans (= Aulacomonas submarina ) form a new family of flagellates (Collodictyonidae) with tubular mitochondrial cristae that is phylogenetically distant from other flagellate groups. Protist 153:59–70 [CrossRef]
     [Google Scholar]
  28. Cavalier-Smith T. 1981; Eukaryote kingdoms: seven or nine?. Biosystems 14:461–481 [CrossRef]
     [Google Scholar]
  29. Cavalier-Smith T. 1983; A 6-kingdom classification and a unified phylogeny. In Endocytobiology II pp 1027–1034Edited by Schwemmler W., Schenk H. E. A. Berlin: Walter de Gruyter;
     [Google Scholar]
  30. Cavalier-Smith T. 1987; Eukaryotes with no mitochondria. Nature 326:332–333 [CrossRef]
     [Google Scholar]
  31. Cavalier-Smith T. 1991; Cell diversification in heterotrophic flagellates. In The Biology of Free-Living Heterotrophic Flagellates pp 113–131Edited by Patterson D. J., Larsen J. Oxford: Clarendon Press;
     [Google Scholar]
  32. Cavalier-Smith T. 1992a; Percolozoa and the symbiotic origin of the metakaryote cell. In Endocytobiology V pp 399–406Edited by Sato S., Ishida M., Ishikawa H. Tübingen, Germany: Tübingen University Press;
     [Google Scholar]
  33. Cavalier-Smith T. 1992b; Origin of the cytoskeleton. In The Origin and Evolution of the Cell pp 79–106Edited by Hartman H., Matsumo K. Singapore: World Scientific;
     [Google Scholar]
  34. Cavalier-Smith T. 1993; Kingdom Protozoa and its 18 phyla. Microbiol Rev 57:953–994
     [Google Scholar]
  35. Cavalier-Smith T. 1997; Amoeboflagellates and mitochondrial cristae in eukaryote evolution: megasystematics of the new protozoan subkingdoms Eozoa and Neozoa. Arch Protistenkd 147:237–258 [CrossRef]
     [Google Scholar]
  36. Cavalier-Smith T. 1998; A revised six-kingdom system of life. Biol Rev Camb Philos Soc 73:203–266 [CrossRef]
     [Google Scholar]
  37. Cavalier-Smith T. 1999; Principles of protein and lipid targeting in secondary symbiogenesis: euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree. J Eukaryot Microbiol 46:347–366 [CrossRef]
     [Google Scholar]
  38. Cavalier-Smith T. 2000; Flagellate megaevolution: the basis for eukaryote diversification. In The Flagellates: Unity, Diversity and Evolution pp 361–390Edited by Green J. C., Leadbeater B. S. C. London: Taylor & Francis;
     [Google Scholar]
  39. Cavalier-Smith T. 2002; The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa. Int J Syst Evol Microbiol 52:297–354
     [Google Scholar]
  40. Corliss J. O. 1994; An interim utilitarian (“user-friendly”) hierarchical classification and characterization of the Protists. Acta Protozool 33:1–51
     [Google Scholar]
  41. Dacks J., Roger A. J. 1999; The first sexual lineage and the relevance of facultative sex. J Mol Evol 48:779–783 [CrossRef]
     [Google Scholar]
  42. Dacks J. B., Silberman J. D., Simpson A. G. B., Moriya S., Kudo T., Ohkuma M., Redfield R. 2001; Oxymonads are closely related to the excavate taxon Trimastix . Mol Biol Evol 18:1034–1044 [CrossRef]
     [Google Scholar]
  43. de Queiroz K., Gauthier J. 1992; Phylogenetic taxonomy. Annu Rev Ecol Syst 23:449–480 [CrossRef]
     [Google Scholar]
  44. Desser S. S., Hong H., Siddall M. E., Barta J. R. 1993; An ultrastructural study of Brugerolleia algonquinensis gen. nov., sp. nov. (Diplomonadida; Diplomonadina), a flagellate parasite from the blood of frogs from Ontario, Canada. Eur J Protistol 2972–80 [CrossRef]
     [Google Scholar]
  45. Edgcomb V. P., Roger A. J., Simpson A. G. B., Kysela D. T., Sogin M. L. 2001; Evolutionary relationships among “jakobid” flagellates as indicated by alpha- and beta-tubulin phylogenies. Mol Biol Evol 18:514–522 [CrossRef]
     [Google Scholar]
  46. Embley T. M., Hirt R. P. 1998; Early branching eukaryotes?. Curr Opin Genet Dev 8:624–629 [CrossRef]
     [Google Scholar]
  47. Eriksson T. 1999 autodecay 4.0. Bergius Foundation, Royal Swedish Academy of Sciences Stockholm, Sweden:
     [Google Scholar]
  48. Eyden B. P., Vickerman K. 1975; Ultrastructure and vacuolar movements in the free-living diplomonad Trepomonas agilis Klebs. J Protozool 22:54–66 [CrossRef]
     [Google Scholar]
  49. Farmer M. A., Triemer R. E. 1988; Flagellar systems in the euglenoid flagellates. Biosystems 21:283–291 [CrossRef]
     [Google Scholar]
  50. Fenchel T., Patterson D. J. 1986; Percolomonas cosmopolitus (Ruinen) n. gen., a new type of filter feeding flagellate from marine plankton. J Mar Biol Assoc U K 66:465–482 [CrossRef]
     [Google Scholar]
  51. Fenchel T., Finlay B. J. 1995 Ecology and Evolution in Anoxic Worlds Oxford: Oxford University Press;
     [Google Scholar]
  52. Flavin M., Nerad T. A. 1993; Reclinomonas americana n. g., n. sp. a new freshwater heterotrophic flagellate. J Eukaryot Microbiol 40:172–179 [CrossRef]
     [Google Scholar]
  53. Friend D. S. 1966; The fine structure of Giardia muris . J Cell Biol 29:317–332 [CrossRef]
     [Google Scholar]
  54. Grassé P.-P. 1952; Classe des Zooflagellés: Zooflagellata ou Zoomastigina. In Traité de Zoologie vol. 1, fasc. 1 pp 963–982Edited by Grassé P.-P. Paris: Masson; in French
    [Google Scholar]
  55. Hinkle G., Sogin M. L. 1993; The evolution of the Vahlkampfiidae as deduced from 16S-like ribosomal RNA analysis. J Eukaryot Microbiol 40:599–603 [CrossRef]
     [Google Scholar]
  56. Hirt R. P., Logsdon J. M. Jr, Healy B., Dorey M. W., Doolittle W. F., Embley T. M. 1999; Microsporidia are related to fungi: evidence from the largest subunit of RNA polymerase II and other proteins. Proc Natl Acad Sci U S A 96:580–585 [CrossRef]
     [Google Scholar]
  57. Holberton D. V. 1973; Fine structure of the ventral disk apparatus and the mechanism of attachment in the flagellate Giardia muris . J Cell Sci 13:11–41
     [Google Scholar]
  58. Horner D. S., Embley T. M. 2001; Chaperonin 60 phylogeny provides further evidence for secondary loss of mitochondria among putative early-branching eukaryotes. Mol Biol Evol 18:1970–1975 [CrossRef]
     [Google Scholar]
  59. Keeling P. J., Doolittle W. F. 1997; Widespread and ancient distribution of a noncanonical genetic code in diplomonads. Mol Biol Evol 14:895–901 [CrossRef]
     [Google Scholar]
  60. Keeling P. J., Leander B. S. 2003; Characterisation of a non-canonical genetic code in the oxymonad Streblomastix strix . J Mol Biol 326:1337–1349 [CrossRef]
     [Google Scholar]
  61. Kulda J., Nohynková E. 1978; Flagellates of the human intestine and of intestines of other species. In Parasitic Protozoa vol 2 pp 1–138Edited by Kreier J. P. New York: Academic Press;
     [Google Scholar]
  62. Leander B. S., Keeling P. J. 2003; Morphostasis in alveolate evolution. Trends Ecol Evol 18:395–402 [CrossRef]
     [Google Scholar]
  63. Leander B. S., Triemer R. E., Farmer M. A. 2001; Character evolution in heterotrophic euglenids. Eur J Protistol 37:337–356 [CrossRef]
     [Google Scholar]
  64. Lipscomb D. L. 1989; Relationships among the eukaryotes. In The Hierarchy of Life pp 161–178Edited by Fernholm B., Bremer K., Jörnvall H. Amsterdam: Elsevier;
     [Google Scholar]
  65. Mignot J. P., Brugerolle G. 1975; Etude ultrastructurale du flagelle phagotrophe Colponema loxodes Stein. Protistologica 11:429–444 in French
    [Google Scholar]
  66. Moestrup Ø. 2000; The flagellate cytoskeleton: introduction of a general terminology for microtubular flagellar roots in protists. In The Flagellates: Unity, Diversity and Evolution Edited by Green J. C., Leadbeater B. S. C. London: Taylor & Francis;
     [Google Scholar]
  67. Moriya S., Dacks J. B., Takagi A., Noda S., Ohkuma M., Doolittle W. F., Kudo T. 2003; Molecular phylogeny of three oxymonad genera: Pyrsonympha , Dinenympha and Oxymonas . J Eukaryot Microbiol 50:190–197 [CrossRef]
     [Google Scholar]
  68. Morrison H. G., Roger A. J., Nystul T. G., Gillin F. D., Sogin M. L. 2001; Giardia lamblia expresses a proteobacterial-like DnaK homolog. Mol Biol Evol 18:530–541 [CrossRef]
     [Google Scholar]
  69. Mylnikov A. P. 1989; The fine structure and systematic position of Histiona aroides (Bicoecales. Bot Zh 74:184–189 in Russian
    [Google Scholar]
  70. Mylnikov A. P. 1991; Diversity of flagellates without mitochondria. In The Biology of Free-Living Heterotrophic Flagellates pp 149–158Edited by Patterson D. J., Larsen J. Oxford: Clarendon Press;
     [Google Scholar]
  71. Nielsen M. H., Ludvik J., Nielsen R. 1966; On the ultrastructure of Trichomonas vaginalis Donné. J Microsc (Paris) 5:229–250
     [Google Scholar]
  72. O'Kelly C. J. 1993; The jakobid flagellates: structural features of Jakoba , Reclinomonas and Histiona and implications for the early diversification of eukaryotes. J Eukaryot Microbiol 40:627–636 [CrossRef]
     [Google Scholar]
  73. O'Kelly C. J. 1997; Ultrastructure of trophozoites, zoospores and cysts of Reclinomonas americana Flavin & Nerad, 1993 (Protista incertae sedis : Histionidae). Eur J Protistol 33:337–348 [CrossRef]
     [Google Scholar]
  74. O'Kelly C. J., Nerad T. A. 1999; Malawimonas jakobiformis n. gen., n. sp. (Malawimonadidae fam. nov.): a Jakoba -like heterotrophic nanoflagellate with discoidal mitochondrial cristae. J Eukaryot Microbiol 46:522–531 [CrossRef]
     [Google Scholar]
  75. O'Kelly C. J., Farmer M. A., Nerad T. A. 1999; Ultrastructure of Trimastix pyriformis (Klebs) Bernard et al. : similarities of Trimastix species with retortamonad and jakobid flagellates. Protist 150:149–162 [CrossRef]
     [Google Scholar]
  76. Page F. C., Blanton R. L. 1985; The Heterolobosea (Sarcodina: Rhizopoda), a new class uniting the Schizopyrenida and the Acrasidae (Acrasida. Protistologica 21:121–132
     [Google Scholar]
  77. Patterson D. J. 1988; The evolution of protozoa. Mem Inst Oswaldo Cruz 83:Suppl. 1580–600 [CrossRef]
     [Google Scholar]
  78. Patterson D. J. 1990; Jakoba libera (Ruinen, 1938), a heterotrophic flagellate from deep oceanic sediments. J Mar Biol Assoc U K 70:381–393 [CrossRef]
     [Google Scholar]
  79. Patterson D. J. 1994; Protozoa: evolution and systematics. In Progress in Protozoology pp 1–14Edited by Hausmann K., Hülsmann N. Berlin: Gustav Fischer Verlag;
     [Google Scholar]
  80. Patterson D. J. 1999; The diversity of eukaryotes. Am Nat 154:SupplS96–S124 [CrossRef]
     [Google Scholar]
  81. Patterson D. J., Zölffel M. 1991; Heterotrophic flagellates of uncertain taxonomic position. In The Biology of Free-Living Heterotrophic Flagellates pp 427–475Edited by Patterson D. J., Larsen J. Oxford: Clarendon Press;
     [Google Scholar]
  82. Patterson D. J., Rogerson A., Vørs N. 2000a; Class Heterolobosea. In The Illustrated Guide to the Protozoa, 2nd edn. pp 1104–1111Edited by Lee J. J., Leedale G. F., Bradbury P. Lawrence, KS: Society of Protozoologists;
     [Google Scholar]
  83. Patterson D. J., Vørs N., Simpson A. G. B., O'Kelly C. J. 2000b; Residual free-living and predatory heterotrophic flagellates. In The Illustrated Guide to the Protozoa , 2nd edn. pp 1302–1328Edited by Lee J. J., Leedale G. F., Bradbury P. Lawrence, KS: Society of Protozoologists;
     [Google Scholar]
  84. Philippe H., Adoutte A. 1998; The molecular phylogeny of Eukaryota: solid facts and uncertainties. In Evolutionary Relationships Among Protozoa pp 25–56Edited by Coombs G. H., Vickerman K., Sleigh M. A., Warren A. London: Chapman & Hall;
     [Google Scholar]
  85. Philippe H., Lopez P., Brinkmann H., Budin K., Germot A., Laurent J., Moreira D., Müller M., Le Guyader H. 2000; Early-branching or fast-evolving eukaryotes? An answer based on slowly evolving positions. Proc R Soc Lond B Biol Sci 267:1213–1221 [CrossRef]
     [Google Scholar]
  86. Radek R. 1994; Monocercomonoides termitis n. sp., an oxymonad from the lower termite Kalotermes sinaicus . Arch Protistenkd 144:373–382 [CrossRef]
     [Google Scholar]
  87. Roger A. J. 1999; Reconstructing early events in eukaryotic evolution. Am Nat 154:SupplS146–S163 [CrossRef]
     [Google Scholar]
  88. Roger A. J., Svärd S. G., Tovar J., Clark C. G., Smith M. W., Gillin F. D., Sogin M. L. 1998; A mitochondrial-like chaperonin 60 gene in Giardia lamblia : evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria. Proc Natl Acad Sci U S A 95:229–234 [CrossRef]
     [Google Scholar]
  89. Ruinen J. 1938; Notizen uber Salzflagellaten. II. Uber die Verbreitung der Salzflagellaten. Arch Protistenkd 90:210–258 in German
    [Google Scholar]
  90. Siddall M. E., Hong H., Desser S. S. 1992; Phylogenetic analysis of the Diplomonadida (Wenyon, 1926). Brugerolle, 1975: evidence for heterochrony in protozoa and against Giardia lamblia as a “missing link”. J Protozool 39:361–367 [CrossRef]
     [Google Scholar]
  91. Silberman J. D., Simpson A. G. B., Kulda J., Cepicka I., Hampl V., Johnson P. J., Roger A. J. 2002; Retortamonad flagellates are closely related to diplomonads – implications for the history of mitochondrial function in eukaryote evolution. Mol Biol Evol 19:777–786 [CrossRef]
     [Google Scholar]
  92. Simpson A. G. B. 1997; The identity and composition of the Euglenozoa. Arch Protistenkd 148:318–328 [CrossRef]
     [Google Scholar]
  93. Simpson A. G. B., Patterson D. J. 1999; The ultrastructure of Carpediemonas membranifera (Eukaryota), with reference to the excavate hypothesis. Eur J Protistol 35:353–370 [CrossRef]
     [Google Scholar]
  94. Simpson A. G. B., Patterson D. J. 2001; On core jakobids and excavate taxa: the ultrastructure of Jakoba incarcerata . J Eukaryot Microbiol 48:480–492 [CrossRef]
     [Google Scholar]
  95. Simpson A. G. B., van den Hoff J., Bernard C., Burton H. R., Patterson D. J. 1997; The ultrastructure and systematic position of the euglenozoon Postgaardi mariagerensis , Fenchel et al . Arch Protistenkd 147:213–225 [CrossRef]
     [Google Scholar]
  96. Simpson A. G. B., Bernard C., Patterson D. J. 2000; The ultrastructure of Trimastix marina Kent, 1880 (Eukaryota), an excavate flagellate. Eur J Protistol 36:229–252 [CrossRef]
     [Google Scholar]
  97. Simpson A. G. B., MacQuarrie E. K., Roger A. J. 2002a; Early origin of canonical introns. Nature 419:270 [CrossRef]
     [Google Scholar]
  98. Simpson A. G. B., Radek R., Dacks J. B., O'Kelly C. J. 2002b; How oxymonads lost their groove: an ultrastructural comparison of Monocercomonoides and excavate taxa. J Eukaryot Microbiol 49:239–248 [CrossRef]
     [Google Scholar]
  99. Simpson A. G. B., Roger A. J., Silberman J. D., Leipe D. D., Edgcomb V. P., Jermiin L. S., Patterson D. J., Sogin M. L. 2002c; Evolutionary history of ‘early diverging’ eukaryotes: the excavate taxon Carpediemonas is a close relative of Giardia . Mol Biol Evol 19:1782–1791 [CrossRef]
     [Google Scholar]
  100. Sleigh M. A. 1988; Flagellar root maps allow speculative comparisons of root patterns and of their ontogeny. Biosystems 21:277–282 [CrossRef]
     [Google Scholar]
  101. Sleigh M. A. 1989 Protozoa and other Protists London: Edward Arnold;
     [Google Scholar]
  102. Sogin M. L. 1989; Evolution of eukaryotic microorganisms and their small subunit ribosomal RNAs. Am Zool 29:487–499
     [Google Scholar]
  103. Sterud E., Mo T. A., Poppe T. T. 1997; Ultrastructure of Spironucleus barkhanus n. sp. (Diplomonadida Hexamitidae from grayling Thymallus thymallus (L.) (Salmonidae) and Atlantic salmon Salmo salar L. (Salmonidae). J Eukaryot Microbiol 44:399–407 [CrossRef]
     [Google Scholar]
  104. Stiller J. W., Hall B. D. 1999; Long-branch attraction and the rDNA model of early eukaryotic evolution. Mol Biol Evol 16:1270–1279 [CrossRef]
     [Google Scholar]
  105. Swofford D. L. 2000 paup*: Phylogenetic Analysis Using Parsimony (*and other methods), version 4 Sunderland, MA: Sinauer Associates;
     [Google Scholar]
  106. Tachezy J., Sánchez L. B., Müller M. 2001; Mitochondrial type iron-sulfur cluster assembly in the amitochondriate eukaryotes Trichomonas vaginalis and Giardia intestinalis , as indicated by the phylogeny of IscS. Mol Biol Evol 18:1919–1928 [CrossRef]
     [Google Scholar]
  107. Tovar J., Leon-Avila G., Sánchez L. B., Sutak R., Tachezy J., van der Geizen M., Hernández M., Müller M., Lucocq J. M. 2003; Mitochondrial remnant organelles of Giardia function in iron-sulphur cluster metabolism. Nature in press
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/ijsem/10.1099/ijs.0.02578-0
Loading
Cytoskeletal organization, phylogenetic affinities and systematics in the contentious taxon Excavata (Eukaryota)
Int J Syst Evol Microbiol 53, 1759 (2003); https://doi.org/10.1099/ijs.0.02578-0
/content/journal/ijsem/10.1099/ijs.0.02578-0
/content/journal/ijsem/10.1099/ijs.0.02578-0
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error