Abstract
The genomic structures of spirochete species are not well characterized, and genetic studies on these organisms have been hampered by lack of a genetic exchange mechanism in these bacteria. In view of these observations, pulsed-field gel electrophoresis was used to examine the genomes of Leptospira species. Live cells, prepared in agarose plugs, were lysed in situ, and the DNA was analyzed under different electrophoretic conditions. Pulsed-field gel electrophoresis of DNA digested with infrequently cutting restriction enzymes showed that the genome of Leptospira interrogans serovar canicola is approximately 3.1 Mb, while that of the saprophytic L. biflexa serovar patoc I is 3.5 Mb. DNA forms of approximately 2,000 and 350 kb which were present in samples from L. interrogans serovars were not readily detected in nonpathogenic serovars. Three distinct populations, designated type alpha, beta, and gamma, of L. interrogans DNA molecules were further analyzed with two-dimensional gel electrophoresis. Evidence suggested that two of these DNA forms, type alpha and gamma, were linear structures. Pulsed-field gel electrophoresis has proven to be a valuable tool with which to size bacterial genomes and to take the first steps toward characterization of a form of leptospiral DNA which behaves as a linear molecule and which may be related to the virulence of L. interrogans.
Full text
PDF






Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barbour A. G., Garon C. F. The genes encoding major surface proteins of Borrelia burgdorferi are located on a plasmid. Ann N Y Acad Sci. 1988;539:144–153. doi: 10.1111/j.1749-6632.1988.tb31847.x. [DOI] [PubMed] [Google Scholar]
- Barbour A. G. Isolation and cultivation of Lyme disease spirochetes. Yale J Biol Med. 1984 Jul-Aug;57(4):521–525. [PMC free article] [PubMed] [Google Scholar]
- Baril C., Richaud C., Baranton G., Saint Girons I. S. Linear chromosome of Borrelia burgdorferi. Res Microbiol. 1989 Oct;140(8):507–516. doi: 10.1016/0923-2508(89)90083-1. [DOI] [PubMed] [Google Scholar]
- Beverley S. M. Characterization of the 'unusual' mobility of large circular DNAs in pulsed field-gradient electrophoresis. Nucleic Acids Res. 1988 Feb 11;16(3):925–939. doi: 10.1093/nar/16.3.925. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chu G., Vollrath D., Davis R. W. Separation of large DNA molecules by contour-clamped homogeneous electric fields. Science. 1986 Dec 19;234(4783):1582–1585. doi: 10.1126/science.3538420. [DOI] [PubMed] [Google Scholar]
- Ferdows M. S., Barbour A. G. Megabase-sized linear DNA in the bacterium Borrelia burgdorferi, the Lyme disease agent. Proc Natl Acad Sci U S A. 1989 Aug;86(15):5969–5973. doi: 10.1073/pnas.86.15.5969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Frutos R., Pages M., Bellis M., Roizes G., Bergoin M. Pulsed-field gel electrophoresis determination of the genome size of obligate intracellular bacteria belonging to the genera Chlamydia, Rickettsiella, and Porochlamydia. J Bacteriol. 1989 Aug;171(8):4511–4513. doi: 10.1128/jb.171.8.4511-4513.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gardiner K., Laas W., Patterson D. Fractionation of large mammalian DNA restriction fragments using vertical pulsed-field gradient gel electrophoresis. Somat Cell Mol Genet. 1986 Mar;12(2):185–195. doi: 10.1007/BF01560665. [DOI] [PubMed] [Google Scholar]
- Haapala D. K., Rogul M., Evans L. B., Alexander A. D. Deoxyribonucleic acid base composition and homology studies of Leptospira. J Bacteriol. 1969 May;98(2):421–428. doi: 10.1128/jb.98.2.421-428.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hayes L. J., Wright D. J., Archard L. C. Segmented arrangement of Borrelia duttonii DNA and location of variant surface antigen genes. J Gen Microbiol. 1988 Jul;134(7):1785–1793. doi: 10.1099/00221287-134-7-1785. [DOI] [PubMed] [Google Scholar]
- Hyde F. W., Johnson R. C. Genetic relationship of lyme disease spirochetes to Borrelia, Treponema, and Leptospira spp. J Clin Microbiol. 1984 Aug;20(2):151–154. doi: 10.1128/jcm.20.2.151-154.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson R. C. The spirochetes. Annu Rev Microbiol. 1977;31:89–106. doi: 10.1146/annurev.mi.31.100177.000513. [DOI] [PubMed] [Google Scholar]
- Kinashi H., Shimaji M., Sakai A. Giant linear plasmids in Streptomyces which code for antibiotic biosynthesis genes. 1987 Jul 30-Aug 5Nature. 328(6129):454–456. doi: 10.1038/328454a0. [DOI] [PubMed] [Google Scholar]
- Lecour H., Miranda M., Magro C., Rocha A., Gonçalves V. Human leptospirosis--a review of 50 cases. Infection. 1989 Jan-Feb;17(1):8–12. doi: 10.1007/BF01643489. [DOI] [PubMed] [Google Scholar]
- Lee J. J., Smith H. O. Sizing of the Haemophilus influenzae Rd genome by pulsed-field agarose gel electrophoresis. J Bacteriol. 1988 Sep;170(9):4402–4405. doi: 10.1128/jb.170.9.4402-4405.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Magee B. B., Koltin Y., Gorman J. A., Magee P. T. Assignment of cloned genes to the seven electrophoretically separated Candida albicans chromosomes. Mol Cell Biol. 1988 Nov;8(11):4721–4726. doi: 10.1128/mcb.8.11.4721. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McClelland M., Jones R., Patel Y., Nelson M. Restriction endonucleases for pulsed field mapping of bacterial genomes. Nucleic Acids Res. 1987 Aug 11;15(15):5985–6005. doi: 10.1093/nar/15.15.5985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perfect J. R., Magee B. B., Magee P. T. Separation of chromosomes of Cryptococcus neoformans by pulsed field gel electrophoresis. Infect Immun. 1989 Sep;57(9):2624–2627. doi: 10.1128/iai.57.9.2624-2627.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pyle L. E., Corcoran L. N., Cocks B. G., Bergemann A. D., Whitley J. C., Finch L. R. Pulsed-field electrophoresis indicates larger-than-expected sizes for mycoplasma genomes. Nucleic Acids Res. 1988 Jul 11;16(13):6015–6025. doi: 10.1093/nar/16.13.6015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sakaguchi K. Invertrons, a class of structurally and functionally related genetic elements that includes linear DNA plasmids, transposable elements, and genomes of adeno-type viruses. Microbiol Rev. 1990 Mar;54(1):66–74. doi: 10.1128/mr.54.1.66-74.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schwartz D. C., Cantor C. R. Separation of yeast chromosome-sized DNAs by pulsed field gradient gel electrophoresis. Cell. 1984 May;37(1):67–75. doi: 10.1016/0092-8674(84)90301-5. [DOI] [PubMed] [Google Scholar]
- Smith C. L., Condemine G. New approaches for physical mapping of small genomes. J Bacteriol. 1990 Mar;172(3):1167–1172. doi: 10.1128/jb.172.3.1167-1172.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith C. L., Econome J. G., Schutt A., Klco S., Cantor C. R. A physical map of the Escherichia coli K12 genome. Science. 1987 Jun 12;236(4807):1448–1453. doi: 10.1126/science.3296194. [DOI] [PubMed] [Google Scholar]
- Steele P. E., Carle G. F., Kobayashi G. S., Medoff G. Electrophoretic analysis of Histoplasma capsulatum chromosomal DNA. Mol Cell Biol. 1989 Mar;9(3):983–987. doi: 10.1128/mcb.9.3.983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steere A. C., Grodzicki R. L., Kornblatt A. N., Craft J. E., Barbour A. G., Burgdorfer W., Schmid G. P., Johnson E., Malawista S. E. The spirochetal etiology of Lyme disease. N Engl J Med. 1983 Mar 31;308(13):733–740. doi: 10.1056/NEJM198303313081301. [DOI] [PubMed] [Google Scholar]
- Suwanto A., Kaplan S. Physical and genetic mapping of the Rhodobacter sphaeroides 2.4.1 genome: presence of two unique circular chromosomes. J Bacteriol. 1989 Nov;171(11):5850–5859. doi: 10.1128/jb.171.11.5850-5859.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thiermann A. B. Leptospirosis: current developments and trends. J Am Vet Med Assoc. 1984 Mar 15;184(6):722–725. [PubMed] [Google Scholar]
- Thomas D. D., Comstock L. E. Interaction of Lyme disease spirochetes with cultured eucaryotic cells. Infect Immun. 1989 Apr;57(4):1324–1326. doi: 10.1128/iai.57.4.1324-1326.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vollrath D., Davis R. W. Resolution of DNA molecules greater than 5 megabases by contour-clamped homogeneous electric fields. Nucleic Acids Res. 1987 Oct 12;15(19):7865–7876. doi: 10.1093/nar/15.19.7865. [DOI] [PMC free article] [PubMed] [Google Scholar]