Chromosomal recombination targets in Chlamydia interspecies lateral gene transfer

Genome sequence analysis has demonstrated that there is widespread lateral gene transfer among strains within the species C. trachomatis, and with other closely related Chlamydia species in laboratory experiments. This is in contrast to the complete absence of foreign DNA in the genomes of sequenced clinical C. trachomatis strains. There is no understanding of any mechanisms of genetic transfer in this important group of pathogens. In this report, we demonstrate that interspecies genetic exchange can occur, but that the nature of the fragments exchanged is different than those observed in intraspecies crosses. We also generate a large hybrid strain library that can be exploited to examine important aspects of chlamydial disease.