Meteora sporadica, a protist with incredible cell architecture, is related to Hemimastigophora.
| Autor: | Eglit Y; Institute for Comparative Genomics, Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada., Shiratori T; Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan., Jerlström-Hultqvist J; Institute for Comparative Genomics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada., Williamson K; Institute for Comparative Genomics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada., Roger AJ; Institute for Comparative Genomics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada., Ishida KI; Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan. Electronic address: ishida.kenichiro.gm@u.tsukuba.ac.jp., Simpson AGB; Institute for Comparative Genomics, Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada. Electronic address: asimpso2@dal.ca. |
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| Jazyk: | angličtina |
| Zdroj: | Current biology : CB [Curr Biol] 2024 Jan 22; Vol. 34 (2), pp. 451-459.e6. |
| DOI: | 10.1016/j.cub.2023.12.032 |
| Abstrakt: | "Kingdom-level" branches are being added to the tree of eukaryotes at a rate approaching one per year, with no signs of slowing down. 1 , 2 , 3 , 4 Some are completely new discoveries, whereas others are morphologically unusual protists that were previously described but lacked molecular data. For example, Hemimastigophora are predatory protists with two rows of flagella that were known since the 19 th century but proved to represent a new deep-branching eukaryote lineage when phylogenomic analyses were conducted. 2 Meteora sporadica 5 is a protist with a unique morphology; cells glide over substrates along a long axis of anterior and posterior projections while a pair of lateral "arms" swing back and forth, a motility system without any obvious parallels. Originally, Meteora was described by light microscopy only, from a short-term enrichment of deep-sea sediment. A small subunit ribosomal RNA (SSU rRNA) sequence was reported recently, but the phylogenetic placement of Meteora remained unresolved. 6 Here, we investigated two cultivated Meteora sporadica isolates in detail. Transmission electron microscopy showed that both the anterior-posterior projections and the arms are supported by microtubules originating from a cluster of subnuclear microtubule organizing centers (MTOCs). Neither have a flagellar axoneme-like structure. Sequencing the mitochondrial genome showed this to be among the most gene-rich known, outside jakobids. Remarkably, phylogenomic analyses of 254 nuclear protein-coding genes robustly support a close relationship with Hemimastigophora. Our study suggests that Meteora and Hemimastigophora together represent a morphologically diverse "supergroup" and thus are important for resolving the tree of eukaryote life and early eukaryote evolution. Competing Interests: Declaration of interests The authors declare no competing interests. (Copyright © 2023 Elsevier Inc. All rights reserved.) |
| Databáze: | MEDLINE |
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