Transposable elements (TEs) are powerful facilitators of genome evolution, and hence of phenotypic diversity as they can cause genetic changes of great magnitude and variety. TEs are ubiquitous and extremely ancient, and although harmful to some individuals, they can be very beneficial to lineages. TEs can build, sculpt, and reformat genomes by both active and passive means. Lineages with activ...

We have mapped a region of homology within a 2.2 kilobase segment of plasmids of incompatibility group F I, WHICH IS CONTAINED IN AN EcoRI restriction enzyme fragment bearing genes for autonomous replication; The coordinates of the 2.2 kilobase segment are 46.4F-48.6F on the physical map of the F plasmid. The orgin of vegetative replication has been mapped at 42.5F, at which site F has no seque...

A bacterial plasmid is a species of nonessential extrachromosomal deoxyribonucleic acid (DNA) that replicates autonomously as a stable component of the cell's genome. Naturally occurring plasmids range in size from one to several hundred kilobases and in copy number from one to several hundred per cell. Copy number is a fixed characteristic of any plasmid under constant conditions and is contro...