symbiont Archives - Astrobiology

Hypothetical sequence of events that led to the origin of the purple-green photosymbiosis of P. tenue. See main text for details. Note that all ancestors and extant species remain phagotrophic (or mixotrophic in the case of photosymbiosis). This study has revealed the order of endosymbiont acquisition in P. tenue and potential pre adaptations that facilitated the symbiosis. These insights have, in turn, shed light on the question of how two contrasting photosynthetic symbionts came to exist within the same host. Moreover, we have expanded the known diversity of the genus Pseudoblepharisma by discovering new non photosymbiotic species and confidently establishing the sister relationship between the genera Pseudoblepharisma and Spirostomum in the family Spirostomidae. Our genome-based predictions on the physiology of photosymbiotic Pseudoblepharisma species represent the basis for future experimental work on the identity of the metabolites that are exchanged among symbiotic partners. -- biorxiv.org

Biochemistry & Organic Chemistry, Biophysics, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Status Report

The Phylogenetic Context For The Origin Of A Unique Purple-green Photosymbiosis

by Keith CowingFebruary 9, 2026February 9, 2026

Symbioses are widespread in nature and have been the source of much evolutionary innovation. While some types of symbioses evolved multiple times across space and time (e.g., oxygenic photosymbioses or […]

Geographic map of vent field locations Map data 2025 Google. -- Molecular Ecology

Genomics, Proteomics, Bioinformatics, Status Report

Contrasting Genomic Responses of Hydrothermal Vent Animals and Their Symbionts to Population Decline After the Hunga Volcanic Eruption

by Keith CowingOctober 7, 2025October 7, 2025

Genetic bottlenecks are evolutionary events that reduce the effective size and diversity of natural populations, often limiting a population’s ability to adapt to environmental change.

Symbiotic Bacteria Ride

Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Microbiology & Virology, Press Release, ROVs/Submersibles/Diving, Water/Hycean Worlds & Oceanography

Symbiotic Bacteria Ride Along With Marine Cells In Earth’s Oceanic Upper Layer

by Keith CowingFebruary 13, 2025February 13, 2025

Just as the human body serves as a habitat for bacteria and other microbes, diverse, tiny organisms known as protistshost their own microbiomes.

Bright field microscopic image corresponding to pTERF image showing control S. cerevisiae cox 2-60, and chimeras S. cerevisiae cox2-60-SynJEC3, S. cerevisiae cox2-60-SynBD2, S. cerevisiae cox2-60-SynBD3 and S. cerevisiae cox2-60-SynBD8. Marged image of bright field chimeric cells (at gray) and pTIRF (X100) microscopic images can be predicted using 561 nm laser for visualization of endosymbiont autofluorescence chlorophyl (in red Em.=653/95 nm) from photosynthetically enabled engineered Syn. No such signal was detected from control yeast cells. SP8 Fluorescent confocal microscopic (x63) image of control S. cerevisiae cox 2–60, and endosymbiontic chimera. Marged images: host cell was stained using Conn A-FITC (emission at 510–520 nm wavelength, in green) and cyanobacterial autofluorescence can detected at 616-650 nm wavelength range. The experiment was repeated three times independently with similar results. -- Nature

Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Press Release

New Insight Into Chloroplast Evolution

by Keith CowingDecember 12, 2024December 12, 2024

One of the most momentous events in the history of life involved endosymbiosis — a process by which one organism engulfed another and, instead of ingesting it, incorporated its DNA […]

Illustration of the initially discovered endosymbiont ‘Candidatus Azoamicus ciliaticola’ and its ciliate host. The figure is a composite of a scanning electron microscope image (SEM, grey) and fluorescence images. Visible is the endosymbiont (yellow) and bacterial prey in food vacuoles as well as the large cell nucleus (blue). The outer structure of the weakly fluorescent ciliate as well as the cilia are also visible. Credit S. Ahmerkamp/Max Planck Institute for Marine Microbiology

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Press Release

Oxygen Is Not The Limit: Diversity And Metabolic Potential Of Globally Distributed Endosymbionts

by Keith CowingDecember 10, 2024December 10, 2024

In 2021, scientists at the Max Planck Institute for Marine Microbiology in Bremen, Germany, reported an astonishing new form of symbiosis: They found a unique bacterium that lives inside a […]

Riftia pachiyptila -- CREDIT Peter Girguis

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Microbiology & Virology, Press Release, ROVs/Submersibles/Diving, Sample Return, Water/Hycean Worlds & Oceanography

Giant Deep-sea Vent Tubeworm Symbionts Use Two Carbon Fixation Pathways To Grow At Record Speeds

by Keith CowingJune 14, 2024June 14, 2024

In the deep-sea environment of the East Pacific Rise, where sunlight does not penetrate and the surroundings are known for their extreme temperatures, skull-crushing pressures, and toxic compounds, lives Riftia […]