2026-07-01 カリフォルニア大学バークレー校（UCB）
＜関連情報＞
- https://news.berkeley.edu/2026/07/01/scientists-discover-how-algae-colonized-corals-a-symbiosis-that-fueled-the-growth-of-the-worlds-reefs/
- https://www.cell.com/cell/abstract/S0092-8674(26)00701-4
リソソーム機構の転用が、サンゴ礁を支える細胞内光共生の進化を形作る Co-option of lysosomal machinery shapes the evolution of the intracellular photosymbiosis supporting coral reefs
Shumpei Maruyama ∙ Catherine F. Henderson ∙ Natalie Swinhoe ∙ … ∙ Emily K. Meier ∙ Ty R. Engelke ∙ Phillip A. Cleves
Cell Published:July 1, 2026
DOI:https://doi.org/10.1016/j.cell.2026.06.015
Graphical abstract
Highlights
- The algae-housing symbiosome organelle forms through fusion with lysosomes
- Several lysosomal proteins are required for maintaining and establishing symbiosis
- SLC26A11 convergently evolved to supply carbon for photosynthesis in corals and anemones
- Algal survival within phagolysosomes may drive the repeated evolution of the symbiosome
Summary
Endosymbiosis has spurred the evolution of new organelles across life. Corals and other cnidarians have repeatedly evolved an organelle, called the symbiosome, which houses intracellular algal symbionts. However, the molecular mechanisms enabling this repeated evolution remain unclear. Using the sea anemone Aiptasia, we generated a high-quality proteome of the symbiosome, revealing protein trafficking mechanisms and the types of biomolecules exchanged during symbiosis. Symbiosomal enrichment of lysosomal proteins, visualization of lysosomal fusion, and reduced symbiosis following knockdown of lysosomal genes indicate that the symbiosome functions through extensive co-option of lysosomal proteins. We identified a symbiosomal bicarbonate/sulfate transporter, SLC26A11, and showed through CRISPR/Cas9 mutagenesis that this lysosomal transporter is required for symbiosis in Aiptasia and a reef-building coral. Together, these findings reveal that corals and anemones have repeatedly co-opted lysosomal proteins to concentrate carbon and shuttle metabolites to support photosymbiosis, providing a relatively simple path for the repeated evolution of new photosymbioses.
