Trichomonads are flagellate protozoa that contain an intracellular fibrous rod composed of thousands of microtubules termed the axostyle.
Keywords: flagellates; protozoa; parasite; parabasilids; axostyle; costa
Trichomonads
Nigel Yarlett, Pace University, New York, USA
Published online: April 2001
DOI: 10.1038/npg.els.0001989
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Figure 1. Scanning electron micrograph of dorsal (left) and dorsolateral (right) views of Trichomonas vaginalis. Characteristic structures include four anterior flagella (AF). The recurrent flagellum (RF) can be seen emerging from the periflagellar canal (PC). The margin of the undulating membrane (UM) is typically shorter than the body and consists of the attached part of the recurrent flagellum and the outer accessory filament. The axostyle (A) is well developed and extends beyond the posterior end of the cell. Bar, 5 m. (Reproduced with permission from BM Honigberg (ed.) (
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Figure 2. Transmission electron micrograph of Trichomonas vaginalis. Section through the anterior part of the organism showing the Golgi apparatus (G), a hydrogenosome (H), the axostyle (A), and the costa (C). (Courtesy of Dr M. Vannier-Santos, Universidade Federal do Rio de Janeiro, Brazil.)
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| References | |
| Brown JR and Doolittle WF (1995) Root of the universal tree of life based on ancient aminoacyl-tRNA synthetase gene duplications. Proceedings of the National Academy of Sciences of the USA 92: 2441–2445. | |
| Fukura K, Yamamoto A, Hashimoto T and Goto N (1996) Nucleotide sequence of the SrRNA gene and phylogenetic analysis of Trichomonas tenax. Microbiology and Immunology 40: 183–188. | |
| Gunderson J, Hinkle G, Leipe D et al. (1995) Phylogeny of Trichomonas inferred from small-subunit rRNA sequences. Journal of Eukaryotic Microbiology 42: 411–415. | |
| Häusler T, Stierhof Y-D, Blattner J and Clayton C (1997) Conservation of mitochondrial targeting sequence function in mitochondrial and hydrogenosomal proteins from the early-branching eukaryotes Crithidia, Trypanosoma and Trichomonas. European Journal of Cell Biology 73: 240–251. | |
| book Honigberg BM and Brugerolle G (1989) "Structure". In: Honigberg BM (ed.) Trichomonads Parasitic in Humans, pp. 3–35. New York: Springer-Verlag. | |
| Keeling PJ, Doherty-Kirby AL, Teh EM and Doolittle WF (1996) Linked genes for calmodulin and E2 ubiquitin-conjugating enzyme in Trichomonas vaginalis. Journal of Eukaryotic Microbiology 43: 468–474. | |
| Lahti CJ, Bradley PJ and Johnson PJ (1994) Molecular characterization of the -subunit of Trichomonas vaginalis hydrogenosomal succinyl CoA synthetase. Molecular and Biochemical Parasitology 66: 309–318. | |
| book Lee JJ, Hutner SH and Bovee EC (eds) (1985) Illustrated Guide to the Protozoa. Lawrence, KS: Society of Protozoologists. | |
| Mertens E, Ladror US, Lee JA et al. (1998) The pyrophosphate-dependent phosphofructokinase of the protist, Trichomonas vaginalis, and the evolutionary relationships of protist phosphofructokinases. Journal of Molecular Evolution 47: 739–750. | |
| Paget T and Lloyd D (1990) Trichomonas vaginalis requires traces of oxygen and high concentrations of carbon dioxide for optimal growth. Molecular and Biochemical Parasitology 41: 65–72. | |
| Silberman JD, Clark CG and Sogin ML (1996) Dientamoeba fragilis shares a recent common evolutionary history with the trichomonads. Molecular and Biochemical Parasitology 76: 311–314. | |
| Viscogliosi E and Müller M (1998) Phylogenetic relationships of the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase, from parabasalid flagellates. Journal of Molecular Evolution 47: 190–199. | |
| Yamamoto A, Hashimoto T, Asaga E, Hasegawa M and Goto N (1997) Phylogenetic position of the mitochondrion-lacking protozoan Trichomonas tenax, based on amino acid sequences of elongation factors 1 and 2. Journal of Molecular Evolution 44: 98–105. | |
| Further Reading | |
| Biagini GA, Finlay BJ and Lloyd D (1997) Evolution of the hydrogenosome: mini review. FEMS Microbiology Letters 155: 133–140. | |
| Bui ET, Bradley PJ and Johnson PJ (1996) A common evolutionary origin for mitochondria and hydrogenosomes. Proceedings of the National Academy of Sciences of the USA 93: 9651–9656. | |
| Cavalier-Smith T (1987) The simultaneous symbiotic origin of mitochondria, chloroplasts and microbodies. Annals of the New York Academy of Sciences 503: 55–72. | |
| Horner DS, Hirt RP, Kilvington S, Lloyd D and Embley TM (1996) Molecular data suggests an early acquisition of the mitochondrion endosymbiont. Proceedings of the Royal Society of London Series B 262: 1053–1059. | |
| Karlin S and Brocchieri L (1998) Heat shock protein 70 family: multiple sequence comparisons, function, and evolution. Journal of Molecular Evolution 47: 565–577. | |
| Müller M (1992) Energy metabolism of ancestral eukaryotes: a hypothesis based on the biochemistry of amitochondriate parasitic protists. BioSystems 28: 33–40. | |
| Müller M (1997) Evolutionary origins of trichomonad hydrogenosomes: comment. Parasitology Today 13: 166–167. | |
| Roger AJ, Clark CG and Doolittle WF (1996) A possible mitochondrial gene in the early-branching amitochondriate protist Trichomonas vaginalis. Proceedings of the National Academy of Sciences of the USA 93: 14618–14622. | |
| Sogin ML and Silberman JD (1998) Evolution of the protistan parasites from the perspective of molecular systematics. International Journal of Parasitology 28: 11–20. | |
