Bodo saltans

Vorlage:Wikify Vorlage:Uncat-date Bodo saltans

Kingdom: Protista Phylum: Euglenozoa Class: Kinetoplastea Order: Bodonea Genus: Bodo

Bodo saltans, also published as Pleuromonas jaculans, is a free-living nonparasitic species of kinetoplastid that is distinguished by the organism’s feeding upon bacteria. B. saltans can be found widely distributed throughout the world in both freshwater and marine environments.

B. saltans is a single-celled bean shaped organism 4 to 5 µm in length. B. saltans has two flagella, a short anterior projecting flagellum and a longer posterior-projecting flagellum without hairs (acronematic) that extends beyond the length of the cell.…B. saltans secures itself to the substrate of its aquatic habitat by the tip of a posterior flagellum. Flexing of the posterior flagellum results in a twitching, jumping movement that is characteristic of this species. This type of movement is appears similar to the undulating membrane of the sexually transmitted pathogen Trichomonas vaginalis (TV) and can result in a false-positive diagnosis in cases where B. saltans is a contaminant in test samples where nonsterile saline solution has been used.

Phylogenetic analysis of the mitochondrial RNA editing process and inferred protein sequences in B. saltans appear to show that B. saltans diverged early on from the evolutionary line of kinetoplastids and that this species of Bodonid is more closely related to the trypanosomatids than at least two species of parasitic Bodonids of the genus Cryptobia.

Phylogenetic analysis based on the sequence of the topoisomerase II (topo II) gene provides evidence that B. saltans is a predecessor of the trypanosomatids. Commonly, the molecules of mitochondrial DNA in eukaryotes is circular and replication and transcription result in topological stress that is mitigated by enzymes called topoisomerases. Kinetoplastids possess a single mitochondrion with what is perhaps the most complex network of mitochondrial “kDNA” in small and large circular forms. As a consequence, mitochondrial genes for topoisomerases are available in high quantities that make it an attractive focus of genetic study. It is also the significance of the enzyme class of topoisomerases to the function of Kinetoplastids that makes the topo genes a target for the medical treatment of trypanosomial and leishmanial diseases.

In one phylogentic tree, the parasitic kinetoplastids included two separate groups of species – C. helicis and T. borreli in one group and the trypanosomatids in the other. The non-parasitic free-living B.saltans and B. uncinatus were distributed among the two groups which implies that the bodonids such as B. saltans, may not have been predecessors of the parasitic species. Other studies show that the trypanosomatids evolved realatively late among the kinetoplastids and constitute a monophyletic group, but that the bodonids may be paraphyletic.

The B. saltans organism would fall within the Phylum Euglenida, Class Euglenophyceae according to Margulis and Schwartz, 1988. The Tree of Life website does not appear to “go out on a limb” and organize what it names the “other protists” morethan one level within Euglenozoa. It is primarily at the lower/finer levels that the other available sources differ on whether Kinetoplastea or Kinetoplasta and Bodonea are at the Class or Order level. But the position of the Bodonids, relative to the other Euglenids, appears to be consistent in the various taxonomic classifications. It appears that most of the debate related to B. saltans concerns the phylogeny of these creatures among closely related genera and where the Bodonids lie on the evolutionary path involving the kinetoplastid group.

References:

Blom, Daniël; Annett de Haan; Marlene van den Berg; Paul Sloof; Milan Jirku; Julius Lukes;, Rob Benne. 1998. RNA editing in the free-living bodonid Bodo saltans. Nucleic Acids Research Vol. 26, no. 5 1205-1213. Dolezel, D; M. Jirku, D.A. Maslov and J. Lukes. 2000. Phylogeny of the bodonid flagellates (Kinetoplastida) based on small-subunit rRNA gene sequences. International Journal of Systematic and Evolutionary Microbiology. Vol 50: 1943-1951 Gaziová, Ivana and Julius Lukes. 2003. Mitochondrial and nuclear localization of topoisomerase II in the flagellate Bodo saltans (Kinetoplastida), a species with non-catenated kinetoplast DNA. Jan 16th JBC Papers, American Society for Biochemistry and Molecular Biology. Hänel K. 1979. Systematik und Ökologie der farblosen Flagellaten des Abwassers. Arch Protistenkd 121: 73-137.

Hausmann, Klaus; Hulsmann, Norbert; Radek, Renate; Protistology (3rd Edition) 2003. E. Scheizerbart’sche Verlagsbuchhandlung. Lee, W. J., D.J. Patterson. 1998 Diversity and Geographic Distribution of Free-Living Heterotrophic flagellates. Protist 149: 229-243, updated with data from Al Qassab et al. (2002). Smith, A; S Portsmouth, B Curran, D Warhurst, P Kell and N Saulsbury. 2002. TV or not TV? Sex. Transm. Inf. 78;185-186 Vørs N. 1992. Heterotrophic amoebae, flagellates and heliozoa from the Tvärminne area, Gulf of Finland, in 1988-1990.