Characterization of the complete mitochondrial genome of bull kelp, Nereocystis luetkeana

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

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.

Next-generation sequencing yields the complete organellar genomes of kelp Lessonia flavicans (Lessoniaceae, Phaeophyceae) from the Sub-Antarctic ecoregion of Magallanes, Chile

The generitype Lessonia flavicans Bory is an endemic and important kelp from Sub-Antarctic Magellanic ecoregion that shows affinity to extreme salinity, temperature, and photoperiod conditions. Genomic analysis of L. flavicans from Rinconada Bulnes, Punta Arenas, Chile, resulted in the assembly of its organellar genomes. The L. flavicans complete mitogenome is 37,226 base pairs (bp) in length and contains 66 genes (GenBank accession number MN561186), the complete plastid genome is 130,085 bp and has 173 genes (MN561187) and the data assembled 8205 bp of the nuclear ribosomal cistron (MN561188). The organellar genomes are similar in structure and content to L. spicata (Suhr) Santelices and other Laminariales.

Analysis of the complete organellar genomes of the economically valuable kelp Lessonia spicata (Lessoniaceae, Phaeophyceae) from Chile

Lessonia spicata (Suhr) Santelices is the most ecologically and economically important kelp from Pacific South America. Here, we contribute to the bioinformatics and evolutionary systematics of the species by performing high throughput sequencing on L. spicata from Valparaiso, Chile. The L. spicata complete mitogenome is 37,097 base pairs (bp) in length and contains 66 genes (GenBank accession MK965907), the complete plastid genome is 130,305 bp and has 173 genes (accession MK965908), and the data assembled 7,630 bp of the nuclear ribosomal cistron (accession MK965909). The organellar genomes are similar in structure and content to others published from the Laminariales.