''Synechocystis'' is a genus of
unicellular, freshwater
cyanobacteria in the family
Merismopediaceae. It includes a strain,
''Synechocystis'' sp. PCC 6803, which is a well studied
model organism.

Like all cyanobacteria, ''Synechocystis'' branches on the evolutionary tree from its ancestral root, ''
Gloeobacter violaceus''. ''Synechocystis'' is not
diazotrophic, and is closely related to another model organism, ''
Cyanothece'' ATCC 51442. It has been suggested that originally ''Synechocystis'' possessed the ability to fix atmospheric nitrogen, but lost the genes required for the process.
See also
*
''Synechocystis'' run-and-tumble
References
{{Taxonbar, from=Q7662346
Cyanobacteria genera
Synechococcales
Bacteria genera