Bacteria induce an amoeboid phase in coccolithophores that persists after bloom collapse.

ABSTRACT: Coccolithophores, including bloom-forming species, Gephyrocapsa huxleyi (formerly Emiliania huxleyi), contribute ~1 to 10% of phytoplankton biomass and are critical for oceanic biogeochemical cycles. G. huxleyi is a model system for investigating algal-bacterial-viral interactions and responses to environmental changes and follows a biphasic lifecycle with motile haploid and nonmotile diploid phases. Here, we report a third, "amoeboid" phase: Light and electron microscopy revealed haploid cells rapidly transitioning to an elongated amoeboid cell with reduced motility. Metamorphosis was triggered by exposure to bacteria isolated from G. huxleyi mesocosm blooms, but not by classical phytoplankton stressors including viral infection. The amoeboid phase persisted beyond the collapse of the hap

SUBMITTER: Zweifel ST 

PROVIDER: S-EPMC12383271 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature