Organelle Genome Variation in the Red Algal Genus Ahnfeltia (Florideophyceae)

Kim, Ho-Cheol; Yang, Ji Hyun; Bustamante, Danilo E.; Calderón, Martha S.; Mansilla, Andrés; Maggs, Christine A.; Hansen, Gayle I.; Yoon, Hwan Su

doi:10.3389/fgene.2021.724734

Cited by 2 publications

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References 83 publications

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“…Other red algae have also been shown to have group II introns in their cox1 genes, particularly in the Bangiales, and occasionally in the Florideophyceae (Yang et al, 2015). For example, Ahnfeltia and Grateloupia species contain 1 group II intron in their cox1 gene (DePriest et al, 2014;Kim et al, 2021;Kim et al, 2014;Patil et al, 2023). Currently there are no red algal sequences of species within the Kallymeniaceae (excluding Judithia parasitica and Blastophyllis hombroniana), and Delesseriaceae (excluding undescribed parasite of Hymenenopsis heterophylla and Hymenenopsis sp.)…”

Section: Mitochondrial Genome Comparisonmentioning

confidence: 99%

Characterisation of Red Algal Parasite Mitochondria from Aotearoa

Walford

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<p>Red algal parasites have evolved over 120 times in the class Florideophyceae and are often closely related to their red algal hosts. Only four mitochondrial genomes of parasitic red algae have been sequenced and they are similar in size and are identical in gene order and content as free-living red algae. The mitochondrial genome of Pterocladiophila hemisphaerica, has shown evidence of elevated substitution rates, which may be an indication of early mitochondrial genome evolution. It is unknown if these observed patterns are present in other red algal parasites. This study assembled and annotated the mitochondrial genomes belonging to 11 red algal parasites and their hosts from Aotearoa. Generally, the mitochondrial genomes of these parasites were conserved in their genome size, gene content, and gene order when compared to their closest free-living red algal relative. Multi-gene phylogenetic analysis supports a continuum of relatedness between parasites and their hosts, with most parasites residing in different genera within the same family as their host. One parasite, Choreonema thuretii (Hapalidiales), resides in a different order to its host. Substitution rate (dN/dS) data was calculated for all shared mitochondrial genes. All red algal parasites included showed higher substitution rates when compared to free-living relative. This large comparison shows that mitochondrial genome architecture is highly conserved among parasitic red algae and has shown for the second time, evidence of increased selection in some mitochondrial genes, suggesting early mitochondrial genome evolution. This study sheds light on mitochondrial genome evolution in red algal parasites and uncovers knowledge of the high red algal parasite diversity in Aotearoa.</p>

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Section: Mitochondrial Genome Comparisonmentioning

confidence: 99%

Characterisation of Red Algal Parasite Mitochondria from Aotearoa

Walford

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Comparative structure and evolution of the organellar genomes of Padina usoehtunii (Dictyotales) with the brown algal crown radiation clade

Liu,

Zhang,

Wang

et al. 2024

BMC Genomics

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Background Organellar genomes have become increasingly essential for studying genetic diversity, phylogenetics, and evolutionary histories of seaweeds. The order Dictyotales (Dictyotophycidae), a highly diverse lineage within the Phaeophyceae, is long-term characterized by a scarcity of organellar genome datasets compared to orders of the brown algal crown radiation (Fucophycidae). Results We sequenced the organellar genomes of Padina usoehtunii , a representative of the order Dictyotales, to investigate the structural and evolutionary differences by comparing to five other major brown algal orders. Our results confirmed previously reported findings that the rate of structural rearrangements in chloroplast genomes is higher than that in mitochondria, whereas mitochondrial sequences exhibited a higher substitution rate compared to chloroplasts. Such evolutionary patterns contrast with land plants and green algae. The expansion and contraction of the inverted repeat (IR) region in the chloroplast correlated with the changes in the number of boundary genes. Specifically, the size of the IR region influenced the position of the boundary gene rpl 21, with complete rpl 21 genes found within the IR region in Dictyotales, Sphacelariales and Ectocarpales, while the rpl 21 genes in Desmarestiales, Fucales, and Laminariales span both the IR and short single copy (SSC) regions. The absence of the rbcR gene in the Dictyotales may indicate an endosymbiotic transfer from the chloroplast to the nuclear genome. Inversion of the SSC region occurred at least twice in brown algae. Once in a lineage only represented by the Ectocarpales in the present study and once in a lineage only represented by the Fucales. Photosystem genes in the chloroplasts experienced the strongest signature of purifying selection, while ribosomal protein genes in both chloroplasts and mitochondria underwent a potential weak purifying selection. Conclusions Variations in chloroplast genome structure among different brown algal orders are evolutionarily linked to their phylogenetic positions in the Phaeophyceae tree. Chloroplast genomes harbor more structural rearrangements than the mitochondria, despite mitochondrial genes exhibiting faster mutation rates. The position and the change in the number of boundary genes likely shaped the IR regions in the chloroplast, and the produced structural variability is important mechanistically to create gene diversity in brown algal chloroplast. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-024-10616-4.

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Organelle Genome Variation in the Red Algal Genus Ahnfeltia (Florideophyceae)

Cited by 2 publications

References 83 publications

Characterisation of Red Algal Parasite Mitochondria from Aotearoa

Characterisation of Red Algal Parasite Mitochondria from Aotearoa

Comparative structure and evolution of the organellar genomes of Padina usoehtunii (Dictyotales) with the brown algal crown radiation clade

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