Pseudonocardia are filamentous actinomycetes with ~6Mbp circular genomes, best known as vertically transmitted mutualists of fungus-growing attine ants.
Holmes N, Innocent T, Heine D, Worsley S, Findlay K, Murrell J.C., Wilkinson B, Boomsma JJ and Hutchings MI (2016). Genome analysis of two Pseudonocardia phylotypes associated with Acromyrmex leafcutter ants reveals their biosynthetic potential. Front Microbiol. 7:2073