cyanobacterium endosymbiont of Epithemia clementina EcSB isolate:Gazos Creek Genome sequencing. cyanobacterium endosymbiont of Epithemia clementina EcSB isolate:Gazos Creek

Diatoms in the genus Epithemia posess obligate cyanobacterial endosymbionts. These endosymbionts, referred to as "spheroid bodies" or "diazoplasts", are derived from a once free-living ancestor in the genus Cyanothece and fix nitrogen for the host diatom. This endosymbiosis represents a rare photosynthetic eukaryote that has successfully coupled oxygenic photosynthesis with oxygen-sensitive nitrogenase activity. We report the genome of the endosymbiont of a newly-isolated species, E. clementina, as a model to investigate endosymbiotic acquisition of this critical biological function. Culture isolates were acquired from Gazos Creek, outside of Butano State Park in San Mateo county, California, United States.