RRC ID 55504
著者 Suzuki S, Endoh R, Manabe RI, Ohkuma M, Hirakawa Y.
タイトル Multiple losses of photosynthesis and convergent reductive genome evolution in the colourless green algae Prototheca.
ジャーナル Sci Rep
Abstract Autotrophic eukaryotes have evolved by the endosymbiotic uptake of photosynthetic organisms. Interestingly, many algae and plants have secondarily lost the photosynthetic activity despite its great advantages. Prototheca and Helicosporidium are non-photosynthetic green algae possessing colourless plastids. The plastid genomes of Prototheca wickerhamii and Helicosporidium sp. are highly reduced owing to the elimination of genes related to photosynthesis. To gain further insight into the reductive genome evolution during the shift from a photosynthetic to a heterotrophic lifestyle, we sequenced the plastid and nuclear genomes of two Prototheca species, P. cutis JCM 15793 and P. stagnora JCM 9641, and performed comparative genome analyses among trebouxiophytes. Our phylogenetic analyses using plastid- and nucleus-encoded proteins strongly suggest that independent losses of photosynthesis have occurred at least three times in the clade of Prototheca and Helicosporidium. Conserved gene content among these non-photosynthetic lineages suggests that the plastid and nuclear genomes have convergently eliminated a similar set of photosynthesis-related genes. Other than the photosynthetic genes, significant gene loss and gain were not observed in Prototheca compared to its closest photosynthetic relative Auxenochlorella. Although it remains unclear why loss of photosynthesis occurred in Prototheca, the mixotrophic capability of trebouxiophytes likely made it possible to eliminate photosynthesis.
巻・号 8(1)
ページ 940
公開日 2018-1-17
DOI 10.1038/s41598-017-18378-8
PII 10.1038/s41598-017-18378-8
PMID 29343788
PMC PMC5772498
MeSH Cell Nucleolus / genetics Chlorophyta / genetics* Evolution, Molecular Genome, Plastid / genetics* Photosynthesis / genetics* Phylogeny Plastids / genetics Prototheca / genetics*
IF 4.011
引用数 6
リソース情報
一般微生物 JCM 15793 JCM 9641