Towards a Monograph of Jakobid, Trimastigid and Metamonad Protists

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The jakobid flagellates may be among the most ancestral of livingeukaryotes. Information from the mitochondrial genomes of two jakobidspecies, Jakoba libera and Reclinomonas americana, suggests that theancestors of jakobids were among the first eukaryotes to acquiremitochondria. The jakobids, therefore, may represent an informative modelsystem for the study of the origin and early divergence of eukaryotic cells. To better understand these organisms, a knowledge of their taxonomicdiversity and relationship to other protists is required. We do not havethis knowledge at present.In this "proof of concept" study, existing species descriptions of jakobidflagellates will be assembled and critically analyzed, with examination oftype specimens when these exist. Data on the morphology, ultrastructure,and life history of jakobid species will be obtained from published papersand from new investigations on species isolated from nature. These datawill be used to construct data matrices for phylogenetic analysis. Nuclearsmall-subunit ribosomal RNA gene sequences will be obtained from cultivatedspecies for use as species identifiers (e.g., for subsequent molecularprobe design) and, with the morphological data, for phylogenetic analyses.Preliminary data in these categories will be collected from exemplar taxa ofTrimastigida, Retortamonadida and Diplomonadida, three groups of protiststhat closely resemble the jakobids in many ways and may be their closestrelatives.This work is expected to result in the description of several new jakobidspecies and in preliminary assessments of the relationships of jakobids witheach other and with other protists. The resulting monograph, online and inprint form, together with associated publications, should provide a welcomeresource for persons interested in early organismal evolution and microbialdiversity.