RRC ID 89688
著者 Hirooka S, Fujiwara T, Seger M, Inagaki S, Yamashita S, Tsujino D, Onuma R, Kanesaki Y, Watanabe S, Hirose Y, Ohbayashi R, Takusagawa M, Zhou B, Tomita R, Yagisawa F, Lammers P, Iwane AH, Miyagishima SY.
タイトル Sexual life cycle establishes the unicellular red algae Cyanidiophyceae as a genetically tractable model for eukaryotic evolution.
ジャーナル Plant Cell
Abstract The thermo-acidophilic unicellular algal class Cyanidiophyceae diverged from other red algae soon after primary chloroplast acquisition. Cyanidiophyceae possess extremely simple genomes (8.7 to 17.8 Mb; approximately 4,800 to 7,800 genes), and the cell wall-less, genetically tractable strain Cyanidioschyzon merolae 10D has served as a model organism. However, its unknown sexual life cycle has limited its utility in studies of evolution and genetics. Here, we show that in the genera Cyanidioschyzon, Cyanidiococcus, and Cyanidium, the cell-walled diploid form, exclusively observed in nature, produces a cell wall-less haploid form when the culture pH is lowered, and both proliferate asexually. Cz. merolae 10D is a haploid clone that forms a cell-walled diploid through mating with other haploid clones. In addition, we generated high-quality genomic resources with phase-specific transcriptomes, identified a compact candidate mating-type region, and developed genetic manipulation systems using the cell wall-less haploids of these genera. We further uncovered phase-specific distributions of histone H3 lysine 27 trimethylation linked to haploid- and diploid-specific gene expression, including transcription factors involved in differentiation associated with sexual reproduction in plants. Additionally, biparental inheritance of organelle DNA occurs following isogamous mating of haploid cells but resolves into uniparental inheritance during diploid proliferation. These advances position Cyanidiophyceae as a powerful model lineage for studying early Archaeplastida evolution, the shared mechanisms of photosynthetic eukaryotes, and environmental adaptation.
巻・号 38(7)
公開日 2026-7-2
DOI 10.1093/plcell/koag148
PII 8702969
PMID 42246676
PMC PMC13353863
MeSH Biological Evolution* Cell Wall / metabolism Haploidy Rhodophyta* / cytology Rhodophyta* / genetics Rhodophyta* / growth & development Rhodophyta* / physiology
リソース情報
藻類 NIES-551 NIES-3638 NIES-4696