SYNOPTIC DESCRIPTION OF THE PHYLUM DIPLONEMEA (CAVALIER-SMITH 1993)
| EUKARYA> EXCAVATA> DISCICRISTATAE> DIPLONEMIDA |
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| The following description of the Phylum was taken from Vickerman (2000c) and Roy et al. (2007). |
I. SYNONYMS: Diplonemea, diplonemids.
II. NUMBER: Poorly studied, about 10 species known.
III. PHYLUM CHARACTERISTICS:
- A. Structure and Physiology
- Cell Form: Unicellular; dorsoventrally flattened with an apical or subapical gullet, from which two flagella may emerge.
- Flagella: Two flagella emerge from the base of the gullet. The anteriorly-directed flagellum has no paraflagellar rod; the posteriorly-directed flagellum lies along the ventral part of the cell in swarmer cells of Rhynchopus.
- Basal Bodies (text with tooltip) Basal bodies (also called kinetosomes) are organelles that are not membrane-bound. All eukaryotic flagella (also called undulipodia) are underlain or attached to the cell by the basal body. The basal body is a microtubular structure with the general formula 9(3)+0. They are indistinguishable from centrioles. : Likely, parallel and inserted at the base of the gullet or reservoir.
- Cell Covering: Dorso-ventrally flattened with a pellicle but no proteinacious strips.
- Chloroplasts: No chloroplasts.
- Food Reserves: Not reported.
- Mitochondria: Their cristae are saccate or discoid (text with tooltip) Discoid cristae (crista, sing.) are swollen tube-like cristae within certain mitochondria. .
- 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. : Present.
- Nucleus:
- Centrioles: Not reported.
- Inclusions and Ejectile Organelles:
- Food vacuoles and extrusosomes (microtubular rods in square pattern).
- B. MITOSIS, MEIOSIS AND LIFE HISTORY
- Mitosis: ?
- Meiosis: Not reported.
- Sexual Reproduction and Life History: Not reported.
- C. Ecology: Marine or freshwater; free-living or opportunistic parasite; saprobic or phagotrophic.
| 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. Busse, I. and A. Preisfeld. 2002. Phylogenetic position of Rhynchopus sp. and Diplonema ambulator as indicated by analyses of euglenozoan small subunit ribosomal DNA. Gene. 284: 83-91. Cavalier-Smith, T. 1993. Kingdom protozoa and its 18 Phyla. Microbiological Reviews. 57: 953-994. Cavalier-Smith, T. 2003a. Protist phylogeny and the high-level classification of Protozoa. European Journal of Protistology. 39:338-348. Lara, E., A. Chatzinotas, and A. G. B. Simpson. 2006. Andalucia (n. gen.) – the deepest branch within Jakobids (Jakobida; Excavata), based on morphological and molecular study of a new flagellate from soil. Journal of Eukaryotic Microbiology. 53(2): 112-120. Marande, W., J. Lukes, and G. Burger. 2005. Unique mitochondrian genome structure in diplonemids, the sister group of the kinetoplastids. Eukaryotic Cell. 4(6): 1137-1146. Moreira, D., P. Lópex-García, and K. Vickerman. 2004. An updated view of kinetoplastid phylogeny using environmental sequences and a closer outgroup: proposal for a new classification of the class Kinetoplastea. International Journal of Systematic and Evolutionary Microbiology. 54: 1861-1875. Patterson, D. J. 1999. The diversity of eukaryotes. American Naturalist. 154 (Suppl.): S96–S124. Roy, J., D. Faktorova, O. Benada, J. Lukes, and G. Burger. 2007. Description of Rhynchopus euleeides n.sp. (Diplonemea), a free-living marine euglenozoan. Journal of Eukaryotic Microbiology. 54(2): 137-145. Simpson, A. G. B., J. Lukes, and A. J. Roger. 2002. The evolutionary history of kinetoplastids and their kinetoplasts. Molecular Biology and Evolution. 19(12): 2071-2083. Simpson, A. G. B., E. E. Gill, H. A. Callahan, R. W. Litaker, and A. J. Roger. 2004. Early evolution within kinetoplastids (Euglenozoa) and the late emergence of the trypanosomatids. Protist. 155:407-422. Simpson, A. G. B., and A. J. Roger. 2004a. Protein phylogenies robustly resolve the deep-level relationships within Euglenozoa. Molecular Phylogenetics and Evolution. 30:201-212. Vickerman, K. 2000c. Diplonemids. In: Lee, J. J., G. F. Leedale, P. Bradbury. An Illustrated Guide to the Protozoa. 2nd edition. Society of Protozoologists. Lawrence, KS. pp. 1157-1159. |
| By Jack R. Holt. Last revised: 02/14/2012 |
