Monophyly of diverse Bigyromonadea and their impact on phylogenomic relationships within stramenopiles

The Genome of the Mitochondrion-Related Organelle in Cepedea longa, a Large Endosymbiotic Opalinid Inhabiting the Recta of Frogs

“…Phylogenetic analysis of concatenated nad genes extracted from mitochondrial genome indicated the paraphyly of Bigyra, comprising Opalozoa and Sagenista, in our study. The topology was in accordance with that of Noguchi et al [ 60 ], Derelle et al [ 15 ] and Cho et al [ 61 ]. Previously, the monophyly of Bigyra was recovered using the dataset of 339 protein alignments when divergent opalozoan lineages ( Blastocystis and Cafeteria ) were successively removed, which indicates that long-branch attraction might hamper phylogenetic reconstruction in the Bigyra lineage due to these fast-evolving taxa [ 15 ].…”

Kaonashia insperata gen. et sp. nov., a eukaryotrophic flagellate, represents a novel major lineage of heterotrophic stramenopiles

“…Feeding on Micromonas pusilla has been reported in a bicosoecid (Parslow et al, 1986), though this may be a special case since M. pusilla is "prokaryote-sized." Although Developea were originally described as bacterivores (Tong, 1995), four Developea species have been cultivated recently as eukaryotrophs on the small kinetoplastid Procryptobia (Aleoshin et al, 2016;Cho et al, 2022), albeit at least one, D. marinus, also feeds on prokaryotes (Aleoshin et al, 2016), and other bacterivorous Developea have been cultured as well (Cho et al, 2022;Weiler et al, 2021). Our cultivation of K. insperata, together with these other recent discoveries, suggests that eukaryotrophy may be more prevalent amongst heterotrophic stramenopile flagellates than generally assumed.…”

“…Given the divergent nature of the SSU rDNA of K. insperata, molecular phylogenetic analyses with additional markers will be crucial to better understand its phylogenetic placement. Transcriptome or genome sequencing would permit phylogenomic analyses, which would be especially powerful since similar data are now available for a wide range of other heterotrophic stramenopile taxa (Cho et al, 2022;Thakur et al, 2019). Some of the di-eukaryote cultures of K. insperata isolate SC are growing on algal prey with sequenced nuclear genomes (Bowler et al, 2008;Curtis et al, 2012;Filloramo et al, 2021).…”

“…While phagotrophic stramenopiles are diverse, sampling biases toward protists that are economically or medically important and toward easy‐to‐culture phototrophs (Sibbald & Archibald, 2017) have contributed to a deficit of sequence data for free‐living heterotrophic stramenopiles as compared to ochrophytes and oomycetes (Cho et al, 2022; Derelle et al, 2016; Thakur et al, 2019). Characterized free‐living phagotrophs are scattered across the stramenopile tree, and the phylogenetic positions of some remain poorly resolved or contentious (Cho et al, 2022; Derelle et al, 2016; Shiratori et al, 2017; Thakur et al, 2019).…”

“…While phagotrophic stramenopiles are diverse, sampling biases toward protists that are economically or medically important and toward easy‐to‐culture phototrophs (Sibbald & Archibald, 2017) have contributed to a deficit of sequence data for free‐living heterotrophic stramenopiles as compared to ochrophytes and oomycetes (Cho et al, 2022; Derelle et al, 2016; Thakur et al, 2019). Characterized free‐living phagotrophs are scattered across the stramenopile tree, and the phylogenetic positions of some remain poorly resolved or contentious (Cho et al, 2022; Derelle et al, 2016; Shiratori et al, 2017; Thakur et al, 2019). Further, much of phagotrophic stramenopile diversity remains undocumented, with new major taxa still discovered regularly through cultivation (Shiratori et al, 2015; Yubuki et al, 2010), and over a dozen major “MAST” groups of marine stramenopiles defined from environmental sequencing without any cultured representatives (Massana et al, 2014; though see Shiratori et al, 2017).…”