Highlights•Endosymbiotic theory explains why organelles resemble free-living
bacteria.•Gene trees are well-suited to testing endosymbiotic theory, but not to replacing …

Free-living amoebae are important predators that control microbial communities. They are
ubiquitous and have been isolated from various natural sources such as soil, freshwater, salt …

The evolution of obligate host-association of bacterial symbionts and pathogens remains
poorly understood. The Rickettsiales are an alphaproteobacterial order of obligate …

Haematopoietic and vascular cells are thought to arise from a common progenitor called the
haemangioblast. Support for this concept has been provided by embryonic stem (ES) cell …

In the rRNA-based tree of life four bacterial phyla, comprising the Planctomycetes,
Verrucomicrobia, Chlamydiae and Lentisphaerae, form together with the candidate phyla …

Rickettsia are best known as strictly intracellular vector‐borne bacteria that cause mild to
severe diseases in humans and other animals. Recent advances in molecular tools and …

Chlamydiae are the major cause of preventable blindness and sexually transmitted disease.
Genome analysis of a chlamydia-related symbiont of free-living amoebae revealed that it is …

Members of the phylum Chlamydiae are obligate intracellular bacteria that were discovered
about a century ago. Although Chlamydiae are major pathogens of humans and animals …

Across the diversity of life, organisms have evolved different strategies to thrive in hypoxic
environments, and microbial eukaryotes (protists) are no exception. Protists that experience …

The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying
several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae …