Pan-genome
In molecular biology a pan-genome (or supra-genome) describes the full complement of genes in a clade (typically applied to species in bacteria and archaea), which can have large variation in gene content among closely related strains). It is the union of the gene sets of all the strains of a clade (e.g. species). The significance of the pan-genome arises in an evolutionary context, especially with relevance to metagenomics, but is also used in a broader genomics context.