Little is known of the genetics of spirochetes, an ancient eubacterial division. In the course of studies of the spirochetal agents of relapsing fever and Lyme disease, Dr. Barbour found that the members of the genus Borrelia have novel genetic elements, linear plasmids. These linear plasmids bear the genes for the major surface proteins of the two species examined in most depth, B. hermsii and B. burgdorferi. In possessing covalently-closed ends, the Borrelia plasmids resemble poxviruses and some eukaryotic replicons. The specific aims of this project are the following: (l) characterization of the structure and function of the linear plasmids, and (2) development of systems for genetic manipulation of spirochetes. The project will wed capability in handling these difficult- to-handle and fastidious organisms with experience in the techniques of molecular genetics. It is anticipated that the studies outlined in this proposal will reveal much about the genetics of spirochetes in general as well as the molecular biology of linear plasmids specifically.
