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item Zuerner, Richard

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/19/2005
Publication Date: 12/5/2005
Citation: Zuerner, R.L. 2005. Comparative genomics of pathogenic leptospira [abstract]. NATO Advanced Research Workshop, Molecular Biology of Spirochetes, 2005, National Institute of Public Health. p. 25.

Interpretive Summary:

Technical Abstract: Pathogenic Leptospira possess two circular chromosomal replicons, CI and CII. The genetic content of CI, the larger replicon, resembles a typical bacterial chromosome and possesses all rRNA, tRNA, and most housekeeping genes. The functional role of the smaller chromosome, CII, is less clear, because many genes on this replicon encode proteins lacking features with defined functions. A key feature of the Leptospira genome is the presence of multiple rearrangements throughout the CI replicon. These rearrangements result in a fluid genetic organization that is mediated, at least in part, by recombination events involving insertion sequences (IS). There are several IS elements in Leptospira and these elements can vary in copy number and distribution throughout the genus. Analysis of antigenic variants of L. interrogans provides evidence that the IS3-like element, IS1501, undergoes duplicative transposition and can cause mutations. Analysis of mutant and wild type loci reveals that IS1501 directs transcription into adjacent sequences, a feature that enables it to function as a mobile promoter. Combined, these date show that IS elements have a prominent role in genetic organization and gene expression in Leptospira. Detailed analysis of Leptospira genomic sequences is revealing many hidden features. Outer membrane proteins identified through genomic sequence analysis may be useful in developing new vaccines. In addition, newly identified potential adhesions and virulence factors are now the subject of detailed studies. These loci provide new insight into the interaction of pathogenic Leptospira with their mammalian hosts.