Characterization of Allobodo yubaba sp. nov. and Novijibodo darinka gen. et sp. nov., cultivable free-living species of the phylogenetically enigmatic kinetoplastid taxon Allobodonidae

Abstract

Kinetoplastids are a large and diverse protist group, spanning ecologically important free-living forms to medically important parasites. The taxon Allobodonidae holds an unresolved position within kinetoplastids, and the sole described species, Allobodo chlorophagus, is uncultivated, being a necrotroph/parasite of macroalgae. Here we describe Allobodo yubaba sp. nov. and Novijibodo darinka gen. nov. et sp. nov., both free-living bacterivores isolated into monoeukaryotic cultures. Electron microscopy shows that both A. yubaba and N. darinka have a microtubular prism in the feeding apparatus (absent in A. chlorophagus), and an ovoid eukinetoplast, rather than pan-kDNA as in A. chlorophagus. Phylogenetic analyses of SSU rDNA sequences robustly place A. yubaba as the sister to A. chlorophagus, while N. darinka branches separately within Allobodonidae, as a sister group of undescribed freshwater isolates. We view Allobodonidae as containing at least four genus-level clades: Allobodo (A. chlorophagus and A. yubaba n. sp.), an undescribed fresh-water clade, an undescribed marine clade, and now Novijibodo—with N. darinka as its sole known member. Electron microscopy also revealed a rod-shaped gram-negative bacterial cytoplasmic endosymbiont in our N. darinka isolate. The availability of these species in monoeukaryotic culture should facilitate future research, including resolving the position of Allobodonidae using phylogenomic approaches.