RefSeq prokaryotic genomes are organized in several new categories such as reference genomes and representative genomes based on curated attributes and assembly and annotation quality measures (www.ncbi.nlm.nih.gov/refseq/about/prokaryotes/) (51). Reference genomes are manually selected ‘gold standard’ complete genomes with high quality annotation and the highest level of experimental support for structural and functional annotation. Currently, a small dataset of 122 reference genomes are manually annotated by collaborating groups and NCBI staff. The reference genomes are available at: http://www.ncbi.nlm.nih.gov/genome/browse/reference/. Representative genomes are computationally calculated and selected to represent diverse species. The representative genomes are available at: www.ncbi.nlm.nih.gov/genome/browse/representative/.
