ABSTRACT
This chapter reviews the DNA and RNA of chlamydiae, the components that have been cloned, and the genetic approaches employed to investigate the mechanisms involved with regulation of the chlamydial developmental cycle. The potential applications of molecular genetics approaches for chlamydial studies are numerous. The genetic relatedness between the two chlamydial species is incredibly low given the morphological, biological, biochemical, and antigenic attributes they both share. Incorporation of labeled precursors into chlamydial DNA has shown that DNA synthesis increases between 12 to 40 hours after infection and then declines. Serotyping Chlamydia trachomatis isolates continues to be a powerful approach for understanding the pathogenesis and natural history of human chlamydial infections. The first analysis of chlamydial RNA evaluated the sedimentation coefficients of predominant RNA species. The electron dense nucleoid of chlamydial elementary bodies has been a morphological hallmark in electron microscopic studies of chlamydiae.
