Induced endosymbiosis between a fungus and bacterium reveals a shift from antagonism to commensalism.

ABSTRACT: Endosymbioses represent dynamic relationships between organisms that may involve antagonistic phases during their emergence. Here, we induced cell-in-cell interactions between the free-living bacterium Ralstonia pickettii and an endosymbiont-free strain of the fungus Rhizopus microsporus using fluidic force microscopy to investigate the early phase of endosymbiosis formation. Following the implantation of bacteria into the cytosol, the rapid proliferation of R. pickettii compromised host fitness, as evidenced by reduced fungal viability, and triggered immune responses characterized by upregulated expression of stress-related defense genes. Vertical transmission of bacteria across fungal generations enabled repeated rounds of selective passaging, ultimately resulting in transcriptional rela

SUBMITTER: Gassler T 

PROVIDER: S-EPMC12663227 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature