Untangling Heteroplasmy, Structure, and Evolution of an Atypical Mitochondrial Genome by PacBio Sequencing
| Autor: | Mohamed Amine Chebbi, Alexandre Cormier, Richard Cordaux, Clément Gilbert, Christopher H. Chandler, Isabelle Marcadé, Bouziane Moumen, Jean Peccoud |
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| Přispěvatelé: | Ecologie, Evolution, Symbiose (EES), Ecologie et biologie des interactions (EBI), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes (LCP-A2MC), Université de Lorraine (UL), Metz Métropole, Évolution, génomes, comportement et écologie (EGCE), Centre National de la Recherche Scientifique (CNRS)-IRD-Université Paris-Sud - Paris 11 (UP11), Woods Hole Oceanographic Institution (WHOI), Université Paris-Sud - Paris 11 (UP11)-IRD-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2017 |
| Předmět: |
0106 biological sciences
0301 basic medicine Mitochondrial DNA [SDV]Life Sciences [q-bio] Locus (genetics) Investigations Biology ENCODE 010603 evolutionary biology 01 natural sciences Genome Evolution Molecular 03 medical and health sciences RNA Transfer Genetics Animals Selection Genetic third-generation sequencing Gene Concerted evolution mtDNA Telomere telomeres Heteroplasmy crustacean isopods 030104 developmental biology [SDE]Environmental Sciences Genome Mitochondrial Transfer RNA concerted evolution Isopoda |
| Zdroj: | Genetics Genetics, Genetics Society of America, 2017, 207 (1), pp.269-280. ⟨10.1534/genetics.117.203380⟩ |
| ISSN: | 1943-2631 0016-6731 |
| DOI: | 10.1534/genetics.117.203380 |
| Popis: | The highly compact mitochondrial (mt) genome of terrestrial isopods (Oniscidae) presents two unusual features. First, several loci can individually encode two tRNAs, thanks to single nucleotide polymorphisms at anticodon sites. Within-individual variation (heteroplasmy) at these loci is thought to have been maintained for millions of years because individuals that do not carry all tRNA genes die, resulting in strong balancing selection. Second, the oniscid mtDNA genome comes in two conformations: a ∼14 kb linear monomer and a ∼28 kb circular dimer comprising two monomer units fused in palindrome. We hypothesized that heteroplasmy actually results from two genome units of the same dimeric molecule carrying different tRNA genes at mirrored loci. This hypothesis, however, contradicts the earlier proposition that dimeric molecules result from the replication of linear monomers—a process that should yield totally identical genome units within a dimer. To solve this contradiction, we used the SMRT (PacBio) technology to sequence mirrored tRNA loci in single dimeric molecules. We show that dimers do present different tRNA genes at mirrored loci; thus covalent linkage, rather than balancing selection, maintains vital variation at anticodons. We also leveraged unique features of the SMRT technology to detect linear monomers closed by hairpins and carrying noncomplementary bases at anticodons. These molecules contain the necessary information to encode two tRNAs at the same locus, and suggest new mechanisms of transition between linear and circular mtDNA. Overall, our analyses clarify the evolution of an atypical mt genome where dimerization counterintuitively enabled further mtDNA compaction. |
| Databáze: | OpenAIRE |
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