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Evolutionary Dynamics and Lateral Gene Transfer in Raphidophyceae Plastid Genomes
Jong Im Kim1, Bok Yeon Jo2, Myung Gil Park3
1Department of Biology, Chungnam National University, Daejeon, South Korea.
Frontiers in Plant Science
|June 30, 2022
Summary
Raphidophycean plastid genomes show surprising structural diversity, with evidence of lateral gene transfer (LGT) from diatoms influencing their evolution. This study reveals unique genome structures and gene origins in these ecologically vital primary producers.
Area of Science:
- * Eukaryotic genomics
- * Evolutionary biology
- * Phycology
Background:
- * Raphidophyceae are ecologically significant primary producers and predators in marine and freshwater systems.
- * Their plastids, resulting from eukaryote-eukaryote endosymbiosis, are of great evolutionary interest.
- * Understanding plastid genome evolution provides insights into eukaryotic evolutionary history.
Purpose of the Study:
- * To investigate the evolutionary history of raphidophyte plastid genomes.
- * To analyze the structural variability and gene origins within these genomes.
- * To explore the role of lateral gene transfer (LGT) in shaping raphidophyte plastid DNA.
Main Methods:
- * Sequencing and comparative analysis of plastid genomes from six Raphidophyceae species (three freshwater, three marine).
- * Inclusion of previously reported plastid genome data for *Heterosigma akashiwo*.
- * Bioinformatic analysis to identify structural variations, gene content, and homologous sequences.
Main Results:
- * Unexpected variability in plastid genome structure was observed among the studied species.
- * *Gonyostomum semen* plastid genome contains a single rRNA operon, lacking genes from the inverted repeat (IR) region.
- * *Fibrocapsa japonica* exhibits the largest IR region and overall plastid genome, including gene-poor regions and foreign DNA.
- * Evidence of lateral gene transfer (LGT) from diatoms, including genes like *tyr*C and *ser*C, and a group II intron in *psb*B.
- * Homology identified between raphidophyte open reading frames and diatom plasmids/plastid genomes.
Conclusions:
- * Raphidophyte plastid genomes exhibit significant structural diversity.
- * Lateral gene transfer (LGT) from diatoms has played a crucial role in the evolution of raphidophyte plastid genomes.
- * The findings contribute to a deeper understanding of plastid genome evolution in eukaryotes.
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