Carsonella ruddii
In 2006 the genome of one strain of Ca. C. ruddi was sequenced at RIKEN in Japan and the University of Arizona. The genome is a circular chromosome of 159,662 base pairs and has a high coding density (97%) with many overlapping genes and reduced gene length. The number of predicted genes was 182, also the lowest on record (NCBI-Genome). Numerous genes considered essential for life seem to be missing, suggesting that the species may have achieved organelle-like status.