title: The low incidence of diversity-generating retroelements in sequenced genomes.
abstract: The insertion of a retrotransposable element is usually associated with adverse or, at best, neutral effects on the host. Diversity-generating retroelements (DGRs) are the first elements that seem to offer a direct selective advantage to their phage or prokaryote host by exact replacement of a short, defined region of a host gene with a hypermutated variant. In a previous study, we presented the software DiGReF for identification of DGRs in genome sequences, and compiled the first comprehensive set of diversity-generating retroelements in public databases. We identified 155 elements in more than 6000 prokaryotic and phage genomes, which was a surprisingly low number. In this commentary, we will discuss the low incidence of these elements and speculate about the biological role of bacterial DGRs.
authors.affiliation: Department of Molecular Genetics; University of Kaiserslautern; Kaiserslautern, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schillinger
authors.forename: Nora
authors.initials: N
authors.lastname: Zingler
keywords: DiGReF; Diversity-generating retroelements; bioinformatics; database bias; formylglycine-generating enzyme; phages