홍조류 미토콘드리아 유전체 진화

Abstract

Rhodophyta is an ancient lineage included in supergroup Plantae that play a role in the eukaryote diversity and evolution. The Florideophyceae (ca. 6100 spp.) is the largest macro algal group that cover 95% of the red algal diversity from the both marine and freshwater habitats, consisting five subclasses: Ahnfeltiophycidae, Corallinophycidae, Hidenbrandiophycidae, Nemaliophycidae, and Rhodymeniophy-cidae. About a dozen of mitochondrial genomes were reported from economic species, such as Chondrus, Gracilariopsis and Porphyra. Here, we have characterized four mitochondrial genomes from four florideophycean subclasses, i.e. Ahnfeltia plicata, Gelidium elegans, Hildenbrandia rubra, Palmaria palmata, and conducted comparative analysis to understand major evolutionary transition. The genome phylogeny supports 34 times of gene rearrangements, including 12 events between Bangiophyceae and Hildenbrandiophycidae, and five events between Hildenbrandiophycidae and Nemaliophycidae. Independent lineage specific gene losses were found in protein coding genes in florideophycean red algae. Only three introns are found in rrl, cox1 and trnI genes that show progressive rrl- and cox1-intron loss, whereas trnI-intron gain in florideophycean species. Intronic-ORFs shows ORF-duplication and pseudogenization by point mutation and deletion in the Florideophyceae.he both marine and freshwater habitats, consisting five subclasses: Ahnfeltiophycidae, Corallinophycidae, Hidenbrandiophycidae, Nemaliophycidae, and Rhodymeniophy-cidae. About a dozen of mitochondrial genomes were reported from economic species, such as Chondrus, Gracilariopsis and Porphyra. Here, we have characterized four mitochondrial genomes from four florideophycean subclasses, i.e. Ahnfeltia plicata, Gelidium elegans, Hildenbrandia rubra, Palmaria palmata, and conducted comparative analysis to understand major evolutionary transition. The genome phylogeny supports 34 times of gene rearrangements, including 12 events between Bangiophyceae and Hildenbrandiophycidae, and five events between Hildenbrandiophycidae and Nemaliophycidae. Independent lineage specific gene losses were found in protein coding genes in florideophycean red algae. Only three introns are found in rrl, cox1 and trnI genes that show progressive rrl- and cox1-intron loss, whereas trnI-intron gain in florideophycean species. Intronic-ORFs shows ORF-duplication and pseudogenization by point mutation and deletion in the Florideophyceae.