Gene fragmentation and RNA editing without borders: eccentric mitochondrial genomes of diplonemids
| Autor: | Gertraud Burger, Matus Valach, Kristína Záhonová, Galina Prokopchuk, Drahomíra Faktorová, Julius Lukeš, Binnypreet Kaur |
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| Rok vydání: | 2020 |
| Předmět: |
Mitochondrial DNA
Lineage (genetic) Euglenozoa Biology Mitochondrion DNA Mitochondrial Genome Chromosomes Transcriptome 03 medical and health sciences 0302 clinical medicine RNA and RNA-protein complexes Genetics Coding region Gene Conserved Sequence Phylogeny 030304 developmental biology 0303 health sciences Base Sequence Genes Evolutionary biology RNA editing Genome Mitochondrial RNA Editing 030217 neurology & neurosurgery |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| Popis: | Diplonemids are highly abundant heterotrophic marine protists. Previous studies showed that their strikingly bloated mitochondrial genome is unique because of systematic gene fragmentation and manifold RNA editing. Here we report a comparative study of mitochondrial genome architecture, gene structure and RNA editing of six recently isolated, phylogenetically diverse diplonemid species. Mitochondrial gene fragmentation and modes of RNA editing, which include cytidine-to-uridine (C-to-U) and adenosine-to-inosine (A-to-I) substitutions and 3′ uridine additions (U-appendage), are conserved across diplonemids. Yet as we show here, all these features have been pushed to their extremes in the Hemistasiidae lineage. For example, Namystynia karyoxenos has its genes fragmented into more than twice as many modules than other diplonemids, with modules as short as four nucleotides. Furthermore, we detected in this group multiple A-appendage and guanosine-to-adenosine (G-to-A) substitution editing events not observed before in diplonemids and found very rarely elsewhere. With >1,000 sites, C-to-U and A-to-I editing in Namystynia is nearly 10 times more frequent than in other diplonemids. The editing density of 12% in coding regions makes Namystynia’s the most extensively edited transcriptome described so far. Diplonemid mitochondrial genome architecture, gene structure and post-transcriptional processes display such high complexity that they challenge all other currently known systems. |
| Databáze: | OpenAIRE |
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