DESCRIPTION OF THE KINGDOM AMOEBOZOAE (LÜHE 1913, em. CORLISS 1984)
| EUKARYA> UNIKONTA> AMOEBOZOAE |
KINGDOM AMOEBOZOAE LINKS
| Amoebozoae (a-mee-ba-ZO-ee) is from two Greek roots that mean “to change” (amoibe -ἀμοιβή) and “animal” (zo-o -ζώο). The reference is to an animal that changes shape. |
| INTRODUCTION TO THE KINGDOM AMOEBOZOAE Organisms in this kingdom tend to make lobopod pseudopodia and have mitochondria with tubular cristae (text with tooltip) Mitochondrial cristae that form as extended saccate structures or tubes are called tubular cristae. (Cavalier-Smith 2004, Margulis and Schwartz, 1998, Barnes, 1984). They generally share the amoeboid or pseudopodial (text with tooltip) A pseudopod (pseudopodium, sing; pseudopodia, pl) is an extension of a naked cell (no wall, pellicle, etc.) that is ephemeral and used for feeding or locomotion. growth form. They all have golgi (text with tooltip) Golgi apparatus (also called dictyosome) is an internal membrane system of stacked flattened sacs. They occur in nearly all eukaryotes and are involved in storing and secreting cellular products. and undergo closed nuclear division (text with tooltip) Mitosis is closed when the segregation of daughter chromosomes occurs within the bounds of the nuclear membrane (the nuclear membrane does not break down). with internal spindles (text with tooltip) An intranuclear spindle elaborates within the nuclear membrane of an organism with closed mitosis. . Some are motile, or can produce motile gametes or swarmer cells. Even though these characters are not exclusive to the Amoebozoae, they do emerge as a monophyletic group in supertree analyses (Baldauf, 2003, Keeling, 2004, Nikolaev et al. 2004). The apusomonads are more problematic as a group. Adl et al. (2005 and 2012) relegate them to a list of eukaryotes with uncertain status. Kuhn et al. (2000) show them emerging as a sister to the amoebozoa+animalia+fungi+glaucophyte+chlorophyte +haptophyte clade. Cavalier-Smith (2002) shows the apusozoans+amoebozoans as a monophyletic group. Cavalier-Smith (2003), Nikolaev et al. (2004), and Berney et al. (2004) also interpret molecular phylogenetic analysis to suggest that they are sisters to all other bikont taxa (all organisms outside of the Unikonts). However, Cavalier-Smith and Chao (2003) claim that the apusomonads evolved from unikont amoebae by the addition of a second flagellum (at the base of the bikont line, and that they are related to the heliozoa). Adl et al. (2012) suggest that the ancestral condition was bikont and that the unikonts lost one of the flagella. Kim et al. (2006) examined the position of Apusomonas (a free-living bikont cell) and concluded that it was a sister to the Opisthokonts and the Amoebozoans were sisters to the Opisthokonts+Apusomonas. Nevertheless, we include the Apusozoa here with uncertain status. The treatment of the Amoebozoae by Adl et al. (2005 and 2012) is quite different from that of other higher taxa within the same articles. They raise Amoebozoae to supergroup level and have eight taxa of the first rank (=kingdoms) within the supergroup. We will retain the simpler version of amoebozoan classification until I see that the system of Adl et al. (2005) is generally accepted. |
FIGURE 1. A cladogram illustrating the relationships between the phyla of the Amoebozoae and the Opisthokonta. The topology is based roughtly on Kim et al. (2006).
| PHYLA OF THE KINGDOM AMOEBOZOAE |
- PROTAMOEBA (Cavalier-Smith 1998)
CONOSA (Cavalier-Smith et al. 2004)
APUSOZOA (Cavalier-Smith 1998)
| LITERATURE CITED Adl, S. M., A. G. B. Simpson, M. A. Farmer, R. A. Andersen, O. R. Anderson, J. R. Barta, S. S. Bowser, G. Brugerolle, R. A. Fensome, S. Fredericq, T. Y. James, S. Karpov, P. Kugrens, J. Krug, C. E. Lane, L. A. Lewis, J. Lodge, D. H. Lynn, D. G. Mann, R. M. McCourt, L. Mendoza, O. Moestrup, S. E. Mozley-Standridge, T. A. Nerad, C. A. Shearer, A. V. Smirnov, F. W. Spiegel, and M. F. J. R. Taylor. 2005. The new higher level classification of eukaryotes with emphasis on the taxonomy of protists. Journal of Eukaryotic Microbiology. 52(5):399-451. Adl, S. A. G. B. Simpson, C. E. Lane, J. Lukes, D. Bass, S. S. Bowser, M. W. Brown, F. Burki, M. Dunthorn, V. Hampl, A. Heiss, M. Hoppenrath, E. Lara, L. L. Gall, D. H. Lynn, H. McManus, E. A. D. Mitchell, S. E. Mozley-Stanridge, L. W. Parfrey, J. Pawlowski, S. Rueckert, L. Shadwick, C. L. Schoch, A. Smirnov, and F. W. Spiegel. 2012. The revised classification of eukaryotes. Journal of Eukaryotic Microbiology. 59(5): 429-493. Baldauf, S. L. 2003a. The deep roots of eukaryotes. Science. 300 (5626): 1701-1703. Barnes. R. S. K. 1984a. Kingdom Animalia. IN: R. S. K. Barnes, ed. A Synoptic Classification of Living Organisms. Sinauer Associates, Inc., Sunderland, MA. pp. 129-257. Berney, C., J. Fahrni, and J. Pawlowski. 2004. How many novel eukaryotic ‘kingdoms’? Pitfalls and limitations of environmental DNA surveys. BioMed Central. Vol. 2. 13 pages. Cavalier-Smith, T. 2002a. The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa. International Journal of Systematic Evolutionary Microbiology. 52:297–354. Cavalier-Smith, T. 2003a. Protist phylogeny and the high-level classification of Protozoa. European Journal of Protistology. 39:338-348. Cavalier-Smith, T. and E. E. Chao. 2003b. Phylogeny of Choanozoa, Apusozoa, and other Protozoa and early eukaryote megaevolution. Journal of Molecular Evolution. 56:540-563. Corliss, J. 1984. The kingdom Protista and its 45 phyla. Biosystems. 17(2): 87-126. Keeling P. J. 2004 The diversity and evolutionary history of plastids and their hosts. American Journal of Botany. 91(10): 1481-1493. Kim, E., A. G. B. Simpson, and L. E. Graham. 2006. Evolutionary relationships of Apusomonads inferred from taxon-rich analyses of 6 nuclear encoded genes. Molecular Biology and Evolution. 23(12):2455-2466. Kühn S., M. Lange, and L. K. Medlin. 2000. Phylogenetic position of Cryothecomonas inferred from nuclear-encoded small subunit ribosomal RNA. Protist. 151: 337–345 Margulis, L. and K. Schwartz. 1998. Five kingdoms, an illustrated guide to the phyla of life on earth. 3rd Edition. W. H. Freeman and Company. New York. Nikolaev, S. I., A. P. Milnikov, C. Berney, J. Fahrni, J. Pawlowsli, V. V. Aleshin, and N. B. Petrov. 2004. Molecular phylogenetic analysis places Percolomonas cosmopolitus within Heterolobosea: evolutionary implications. Journal of Evolutionary Microbiology. 51(5): 575-581. |
| By Jack R. Holt. Last revised: 11/18/2013 |
