해양식물의 진화: 홍조류 미토콘드리아 유전체

Abstract

Rhodophyta (red algae) is one of major producer in the marine ecosystem, and play a role in the evolution of eukaryotic diversity in the biosphere. The class Florideophyceae (ca. 6100 spp.) is the most common macro-algae found in marine habitats. Florideophycean red algae cover more than 95% of the red algal diversity consisting five subclasses, i.e. Ahnfeltiophycidae, Corallinophycidae, Hidenbrandiophycidae, Nemaliophycidae, and Rhodymeniophycidae. Eleven mitochondrial genomes were reported from few economically important species, such as Chondrus, Gelidium, Gracilaria, and Porphyra. Recently, we have characterized ten mitochondrial genomes from representatives of each florideophycean subclasses, e.g. Ahnfeltia plicata, Sporolithon durum, Hildenbrandia rubra, Palmaria palmata, Rhodymenia pseudopalmata, and conducted comparative analysis in order to understand major evolutionary transition. The best hypothesis of mitochondrial genomes support 34 times of gene rearrangement events including 12 events between Bangiophyceae and Hildenbrandiophycidae and 5 events between Hildenbrandiophycidae and Nemaliophycidae. Lineage specific gene losses and protein coding gene reduction trends were found in present study. The group II introns are found in rrl, cox1 and trnI genes that show progressive rrl- and cox1-intron loss, whereas trnI-intron gain in the Florideophyceae. Intronic-ORFs shows ORF-duplication and pseudogenization itats. Florideophycean red algae cover more than 95% of the red algal diversity consisting five subclasses, i.e. Ahnfeltiophycidae, Corallinophycidae, Hidenbrandiophycidae, Nemaliophycidae, and Rhodymeniophycidae. Eleven mitochondrial genomes were reported from few economically important species, such as Chondrus, Gelidium, Gracilaria, and Porphyra. Recently, we have characterized ten mitochondrial genomes from representatives of each florideophycean subclasses, e.g. Ahnfeltia plicata, Sporolithon durum, Hildenbrandia rubra, Palmaria palmata, Rhodymenia pseudopalmata, and conducted comparative analysis in order to understand major evolutionary transition. The best hypothesis of mitochondrial genomes support 34 times of gene rearrangement events including 12 events between Bangiophyceae and Hildenbrandiophycidae and 5 events between Hildenbrandiophycidae and Nemaliophycidae. Lineage specific gene losses and protein coding gene reduction trends were found in present study. The group II introns are found in rrl, cox1 and trnI genes that show progressive rrl- and cox1-intron loss, whereas trnI-intron gain in the Florideophyceae. Intronic-ORFs shows ORF-duplication and pseudogenization