The relapsing fever agent Borrelia hermsii has multiple copies of its chromosome and linear plasmids.

@article{Kitten1992TheRF,
  title={The relapsing fever agent Borrelia hermsii has multiple copies of its chromosome and linear plasmids.},
  author={T Kitten and Alan G Barbour},
  journal={Genetics},
  year={1992},
  volume={132 2},
  pages={311-24}
}
Borrelia hermsii, a spirochete which causes relapsing fever in humans and other mammals, eludes the immune response by antigenic variation of the "Vmp" proteins. This occurs by replacement of an expressed vmp gene with a copy of a silent vmp gene. Silent and expressed vmp genes are located on separate linear plasmids. To further characterize vmp recombination, copy numbers were determined for two linear plasmids and for the 1-megabase chromosome by comparing hybridization of probes to native… CONTINUE READING