Bacterial Pangenome

Abstract

This literature review provides an aggregate data on pan-genome studies since the early 2000s. In molecular biology and genetics, pan-genome is the totality of all genetic information on a group of organisms (species or monophyletic group of organisms) under consideration. Pan-genome is structurally divided into the “core genome”, which contains the genes present in all studied genetic sequences, the “accessory genome”, which is genes common to most genomes (10–95 %), and the “cloud genome”, genes that are not present in all representatives of the species, or genes that are present in only one of the genomes or found in less than 10 % of genomes. Some authors also call the cloud genome the “accessory genome”, which contains “unnecessary” genes or strain-specific genes. Also, one of the important indicators of genetic diversity within a taxon is the concept of open and closed pangenomes, which allows us to judge intraspecific diversity, which is associated with various genetic events. Thus, pangenomics is a rapidly developing area at the intersection of microbiology, bioinformatics, epidemiology, which opens up new horizons in research. Due to the improvement of sequencing methods, the concept of one “standard” or “reference” genome may be inconsistent and quite limited, therefore, for a complete understanding of the picture and replenishment of data, it is possible to use the concept of pangenomes.