Deoxyribonucleic Acid Heterogeneity Between Human and Murine Strains of Chlamydia trachomatis

Abstract

We compared the polynucleotide sequence relationships of three strains of Chlamydia trachomatis of human origin (MRC-1 /G, TW-3, and Lgv), one of murine origin (MoPn), and the MN strain of C. psittaci. The four strains of C. trachomnatis have the same base ratio, about 42.5 moles per cent guanine plus cytosine, which is significantly higher than the base ratio of MN (39.5). Single strands of deoxyribonucleic acid (DNA) fragments of MRC-1/G reassociated with immobilized DNA of TW-3 and Lgv almost as well as with the homologous DNA. The duplexes produced in these reactions were about equally thermostable. On the other hand, reassociations between MRC-1 /G and MoPn involved 60 or 30% of the DNA, depending on the stringency of the conditions for reassociation, and the duplexes were thermolabile. MoPn reassociated only to a very small degree with MN. We also compared glucose catabolism of MRC-l/G, MoPn, and MN under several sets of conditions. These tests failed to reveal any qualitative phenotypic differences among the three strains. It can be concluded that, judging by polynucleotide sequence, the three human strains of C. trachomatis are closely related but appreciably different from a murine strain.

Comparison of Chlamydia psittaci isolates by DNA restriction endonuclease analysis

“…Representatives of the established species C. trachomatis and C. psittaci were easily differentiated by this technique, confirming the findings of Peterson and de la Maza (25) who used 32Pi-labeled DNA preparations in agarose gels. The results also accord with previous DNA characterization by G+C ratio and homology studies (15,41).…”

Restriction endonuclease analysis of DNA from Chlamydia trachomatis biovars

“…The genus Chlamydia is composed of two species, Chlamydia psittaci and Chlamydia trachomatis. These two species share only about a 10% DNA homology, as shown by DNA-DNA hybridization experiments (10,21). From hybridization results, it is not clear whether the two species should be classified within the same genus (13).…”

Utilization of exogenous thymidine by Chlamydia psittaci growing in the thymidine kinase-containing and thymidine kinase-deficient L cells

“…University of Texas, Austin, Tex. 78712. composition of chlamydial DNA (24), is synthesized by the parasite from deoxyuridine monophosphate by a host-independent pathway (8,14,22). A corollary of this conclusion is that the thymidylate pools of the host cell are not available to the parasite as precursors for DNA synthesis.…”