Transcriptome of epibiont Saccharibacteria TM7x during establishment of symbiosis on host Schaalia odontolyticus strain XH001

Nanosynbacter lyticus type strain TM7x was the first cultivated member of the broadly prevelent, but poorly udnerstood Candidate Phylum Radiation super-phylum. TM7x was shown to be an obligate epibiont with a host range including Schaalia odontolyticus strain XH001. The process of infecting a naive host goes through multiple phases, from an initial binding and interaction phase we call the initial encounter, to a rapid die off of infected host cells, killing phase, followed by regrowth of the host cells, regrowth phase, and finally a stable symbiosis between the species, stable symbiosis.To obtain a better understanding of the process by which these species establish a stable symbiosis, we measured the transcriptome using RNA sequencing across the course of infection. We sampled infected host, XH001/TM7x, during the initial interaction, regrowth, and after attaining stable symbiosis, as well as naive host controls grown under the same culture conditions. Overall design: Free TM7x was isolated from infected XH001 hosts. Naive hosts were then exposed to free TM7x and grown for in Brain Heart Infusion media and passaged every 24 hours into new media at an OD600 of 0.1. Naive XH001 was grown using the same passaging as a control. Samples were collected from both XH001/ TM7x and the control 6 hours into passage 0, representing the initial encounter phase, 6, 10, and 15 hours into passage 4, representing the regrowth phase, and 6 hours into passage 6, representing the stable symbiosis phase. Samples were collected in triplicate.