Analysis of organellar genomes in brown algae reveals an independent introduction of similar foreign sequences into the mitochondrial genome

• Published in: Genomics
• Main Authors: Rana, Shivani, Klaus, Valentin, Riehl, Jana, Blanfuné, Aurelie, Reynes, Lauric, Thibaut, Thierry, Bartsch, Inka, Eichinger, Ludwig, Glöckner, Gernot
• Other Authors: Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Brown algae; Mitochondrial lateral gene transfer; Organellar genomes; Phylogeny; [SDU]Sciences of the Universe [physics]; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic
• Online Access: https://hal.archives-ouvertes.fr/hal-03203985; https://hal.archives-ouvertes.fr/hal-03203985/document; https://hal.archives-ouvertes.fr/hal-03203985/file/1-s2.0-S088875432100029X-main.pdf; https://doi.org/10.1016/j.ygeno.2021.01.003

International audience Kelp species (Laminariales, Phaeophyceae) are globally widespread along temperate to Polar rocky coastal lines. Here we analyse the mitochondrial and chloroplast genomes of Laminaria rodriguezii, in comparison to the organellar genomes of other kelp species. We also provide the complete mitochondrial genome sequence of another endemic kelp species from a Polar habitat, the Arctic Laminaria solidungula. We compare phylogenetic trees derived from twenty complete mitochondrial and seven complete chloroplast kelp genomes. Interestingly, we found a stretch of more than 700 bp in the mitochondrial genome of L.rodriguezii, which is not present in any other yet sequenced member of the Phaeophyceae. This stretch matches a protein coding region in the mitochondrial genome from Desmarestia viridis, another brown seaweed. Their high similarity suggests that these sequences originated through independent introduction into the two species. Their origin could have been by infection by yet unknown similar mitoviruses, currently only known from fungi and plants.