Jakoba libera (Ruinen 1938) Patterson 1990

Introduction

Jakoba is a group of jakobid flagellates.  At present there is a single described species, Jakoba libera (Ruinen, 1938) Patterson, 1990.

There are two cultures identified as Jakoba libera for which small subunit ribosomal RNA gene sequences are available - ATCC 50422 and WHOI DB9.  The sequences are 95% identical, and are always recovered as a clade relative to other jakobids (Cavalier-Smith, 2003; Lara et al., 2006).  The Jakoba libera morphospecies, so far, therefore, appears to be a clade.

Characteristics

Jakoba libera is a bacterivorous flagellate with two flagella.  It is free-swimming, but often attaches to surfaces by the anterior flagellum during feeding.  As in other jakobids, and many other excavates, the posterior flagellum beats within a broad ventral groove.  The current generated by the flagellum draws suspended prokaryotes into the groove, where they are phagocytosed.

Jakoba libera has been reported from marine samples, and from hypersaline sites (Patterson, 1990; Ruinen, 1938).

The mitochondrial genome of Jakoba libera, while still remarkably gene-rich, includes fewer genes than other jakobid mitochondrial genomes studied to date (Gray et al., 2004).  For example, only two subunits of eubacterial-type RNA polymerase are encoded by the mitochondrial genome, whereas other jakobids (e.g. Reclinomonas americana) have four mitochondrially-encoded subunits.

Other Names for Jakoba libera (Ruinen 1938) Patterson 1990

• Jakoba Patterson 1990
• Jakobidae

References

Bernard, C., Simpson, A. G. B. & Patterson, D. J. (2000) Some free-living flagellates (Protista) from anoxic habitats. Ophelia 52: 113-142.

Cavalier-Smith, T. (2003) The excavate protozoan phyla Metamonada Grasse emend. (Anaeromonadea, Parabasalia, Carpediemonas, Eopharyngia) and Loukozoa emend. (Jakobea, Malawimonas): their evolutionary affinities and new higher taxa. Int. J. Syst. Evol. Microbiol. 53: 1741-1758.

Gray, M. W., Lang, B. F. & Burger, G. (2004) Mitochondria of protists. Annu. Rev. Genet. 38: 477-525.

Lara, E., Chatzinotas, A., Simpson, A.G.B. (2006) Andalucia (gen. nov,): a new taxon for the deepest branch within jakobids (Jakobida; Excavata), based on morphological and molecular study of a new flagellate from soil. J. Eukaryot. Microbiol. 53: 112-120.

O’Kelly, C. J. (1993) The jakobid flagellates: structural features of Jakoba, Reclinomonas and Histiona and implications for the early diversification of eukaryotes. J. Eukaryot. Microbiol. 40: 627--636.

Patterson, D.J. (1990) Jakoba libera (Ruinen, 1938), a heterotrophic flagellate from deep oceanic sediments. J. Mar. Biol. Ass. U.K. 70: 381-393.

Patterson, D.J., Vørs, N., Simpson, A.G.B. & O'Kelly, C.J. (2002) Residual and predatory heterotrophic flagellates. In: Lee, J.J., Leedale, G.F.& Bradbury P. (ed.) An illustrated guide to the protozoa, second edition. pp 1302-1328. Society of Protozoologists, Lawrence, Kansas.

Rodríguez-Ezpeleta, N., Brinkmann, H., Burger, G., Roger, A.J., Gray, M.W., Philippe, H., Lang, B.F. (2007) Toward resolving the eukaryotic tree: The phylogenetic positions of jakobids and cercozoans. Curr. Biol. 17: 1420-1425.

Ruinen J. (1938) Notizen über Salzflagellaten. II. Über die Verbereitung der Salzflagellaten. Arch Protistenkd 90: 210-258.

Simpson, A.G.B., Roger, A.J., Silberman, J.D., Leipe, D.D., Edgcomb, V.P., Jermiin, L.S., Patterson, D.J. & Sogin, M.L. (2002) Evolutionary history of “early diverging” eukaryotes: the excavate taxon Carpediemonas is a close relative of Giardia. Mol. Biol. Evol. 19: 1782-1791.

Simpson, A.G.B., Perley, T. & Lara, E., (2008) Lateral transfer of the gene for a widely used marker, alpha tubulin, indicated by a multi-protein study of the phylogenetic position of Andalucia (Excavata). Mol. Phylogenet. Evol. 47: 366-377.

Information on the Internet

• Jakoba page in Micro*scope.
• Jakobidae page in Micro*scope.
• Jakoba page in the Protist Image Database (PID).
• Jakoba libera mitochondrial genome - OGMP.