Symbiosis with intracellular bacteria is essential for the nutrition of ticks, particularly through
the biosynthesis of B vitamins. Yet, ticks of the genus Ixodes, which include major vectors of …

Recent discoveries of basal extracellular Rickettsiales have illuminated divergent
evolutionary paths to host dependency in later-evolving lineages. Family Rickettsiaceae …

Symbiosis between prokaryotes and microbial eukaryotes (protists) has broadly impacted
both evolution and ecology. Endosymbiosis led to mitochondria and plastids, the latter …

The rickettsial human pathogen Orientia tsutsugamushi (Ot) is an obligate intracellular Gram-
negative bacterium with one of the most highly fragmented and repetitive genomes of any …

Gene transfer agents (GTAs) are virus-like structures that package and transfer prokaryotic
DNA from donor to recipient prokaryotic cells. Here, we describe widespread GTA gene …

Midichloria spp. are intracellular bacterial symbionts of ticks. Representatives of this genus
colonise mitochondria in the cells of their hosts. To shed light on this unique interaction we …

Abstract The order Rickettsiales (Alphaproteobacteria) encompasses multiple diverse
lineages of host-associated bacteria, including pathogens, reproductive manipulators, and …

Symbiomonas scintillans Guillou et Chrétiennot-Dinet, 1999 is a tiny (1.4 μm) heterotrophic
microbial eukaryote. The genus was named based on the presence of endosymbiotic …

Comparing obligate endosymbionts with their free-living relatives is a powerful approach to
investigate the evolution of symbioses, and it has led to the identification of several genomic …

Recent metagenome-assembled genome (MAG) analyses have profoundly impacted
Rickettsiology systematics. The discovery of basal lineages (novel families Mitibacteraceae …