Colpodella
| Colpodella | |
|---|---|
| |
Scientific classification
| |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | TSAR |
| Clade: | SAR |
| Clade: | Alveolata |
| Phylum: | Apicomplexa |
| Order: | Colpodellida |
| Family: | Colpodellidae Simpson & Patterson, 1996 |
| Genus: | Colpodella Cienkowski, 1865 |
| Species | |
|
See text. | |
| Synonyms | |
| |
Colpodellais agenusofalveolatescomprising 5species,and two further possible species:[1]They share all thesynapomorphiesofapicomplexans,but are free-living, rather thanparasitic.[1]Many members of this genus were previously assigned to a different genus -Spiromonas.
Thetype speciesisColpodella pugnaxCienkowski 1865.
Description
[edit]These are small (< 20μmin diameter) flagellated protists. Thelife cycleof consists of two main stages:flagellatedtrophozoitesandcysts,which are the reproductive stage in the life cycle.
Morphologically the trophozoites ofColpodellaare similar toPerkinsuszoospores,although the two taxa are not specifically related. The motile stages of both genera have a pair of anterior orthogonalflagella,vesicular mitochondrial cristae, inner alveolar membranes and micropores. BothColpodellaandPerkinsusspecies have open sided truncated conoids (sometimes called pseudoconoids),rhoptriesthat occupy the length of the cell and smallermicronemes.Both the rhoptries and micronemes arise at the anterior portion of the cell. A three-layered pellicle lies beneath theplasma membraneand is otherwise composed of the alveolar membranes and widely separatedmicrotubulesthat arise subapically. Some species have extrusive organelles (trichocysts).
UnlikePerkinsus,Colpodellaare free-living and are voracious predators of other free-livingprotists.Most species apparently penetrate through the cell membrane and consume the prey's cytoplasm - this mode of feeding is known asmyzocytosis.While feeding the predator attaches its anterior portion - the rostrum - to the prey. The rostrum contains the pseudoconoid, which transforms into a ring ofmicrotubulesencircling the attachment zone. The cytoplasm of the prey is then drawn into a large posterior foodvacuole.
Following feeding cells lose their flagella, become spherical, encyst and divide (i.e. reproduce). Thecystsare simple spheres. The food vacuole appears as a large centralvacuolein the cyst; as division progresses the remnant vacuole material is reduced to a residual body. Typically Colpodella divides into four daughter cells (sometimes just two).[1]This is in contrast to true Apicomplexa andPerkinsus,which typically produce many more daughter cells during reproduction -Perkinsusspecies can produce up to 32 cells, for example, whileToxoplasmaproduces 128. The daughter cells grow flagella, the cyst wall ruptures, and the cells swim away, leaving the residual body behind. A possible sexual process has been observed in at least two species.[1]
Taxonomy
[edit]This family appears to be a sister clade to the Apicomplexa.[2]Their life style may be representative of the free living ancestors of the Apicomplexa. One significant difference is that this genus, like thePerkinsea,have an open sided conoid (pseudoconoid) while the Apicomplexa which possess a conoid (theConoidasida) have a closed conoid.
Another genus in this family isAcrocoelus.
Species currently within genus:
- Colpodella edax(Klebs 1892) Simpson & Patterson 1996
- Colpodella pseudoedaxMylnikov & Mylnikov 2007
- Colpodella pugnaxCienkowsky 1865 non Simpson & Patterson 1996
- Colpodella angusta(Dujardin 1841) Simpson & Patterson 1996[Dingensia angusta(Dujardin 1841) Patterson & Zoelffel 1991]
Species transferred to other genera:[3]
- Colpodella gonderi(Foissner & Foissner 1984) Simpson & Patterson 1996asMicrovorax gonderi(Foissner & Foissner 1984) Cavalier-Smith 2017
- Colpodella perforans(Hollande 1938) Patterson & Zölffel 1991asChilovora perforans(Hollande 1938) Cavalier-Smith & Chao 2004
- Colpodella ponticaMylnikov 2000asVoromonas pontica(Mylnikov 2000) Cavalier-Smith & Chao 2004
- Colpodella pugnaxSimpson & Patterson 1996 non Cienkowsky 1865asAlgovora pugnax(Simpson & Patterson 1996) Cavalier-Smith & Chao 2004
- Colpodella tetrahymenaeCavalier-Smith 2004asMicrovorax tetrahymenae(Cavalier-Smith & Chao 2004) Cavalier-Smith 2017
- Colpodella turpisSimpson & Patterson 1996asAlgovora turpis(Simpson & Patterson 1996) Cavalier-Smith & Chao 2004
- Colpodella unguisPatterson & Simpson 1996asColpovora unguis(Patterson & Simpson 1996) Cavalier-Smith 2017
- Colpodella vorax(Kent, 1880) Simpson & Patterson, 1996asDinomonas voraxKent 1880
Clinical
[edit]These organisms are not normally considered to be human pathogens. However, a report of an infection of theerythrocytesin a Chinese woman with a deficiency ofnatural killer cellshas been reported.[4]
References
[edit]- ^abcdAlastair G. B. Simpson; David J. Patterson (1996). "Ultrastructure and identification of the predatory flagellateColpodella pugnaxCienkowski (Apicomplexa) with a description ofColpodella turpisn. sp. and a review of the genus ".Systematic Parasitology.33(3): 187–198.doi:10.1007/BF01531200.
- ^Brian S. Leander; Olga N. Kuvardina; Vladimir V. Aleshin; Alexander P. Mylnikov; Patrick J. Keeling (2003)."Molecular phylogeny and surface morphology ofColpodella edax(Alveolata): insights into the phagotrophic ancestry of apicomplexans "(PDF).Journal of Eukaryotic Microbiology.50(5): 334–340.doi:10.1111/j.1550-7408.2003.tb00145.x.PMID14563171.Archived fromthe original(PDF)on 2012-04-01.Retrieved2011-10-14.
- ^Cavalier-Smith, Thomas (2018)."Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences".Protoplasma.255(1): 297–357.doi:10.1007/s00709-017-1147-3.PMC5756292.PMID28875267.
- ^Yuan CL, Keeling PJ, Krause PJ, Horak A, Bent S, Rollend L, Hua XG (2012)Colpodellaspp.-like parasite infection in woman, China. Emerg Infect Dis 18(1):125-127 doi: 10.3201/eid1801.110716
External links
[edit]- Leander, Brian S.; Keeling, Patrick J. (2003)."Morphostasis in alveolate evolution"(PDF).Trends in Ecology and Evolution.18(8): 395–402.CiteSeerX10.1.1.452.8288.doi:10.1016/S0169-5347(03)00152-6.Archived fromthe original(PDF)on 2012-04-01.Retrieved2011-10-14.