Electron microscopic heteroduplex study and restriction endonuclease cleavage analysis of the DNA genomes of three lactic streptococcal bacteriophages.
AUTOR(ES)
Jarvis, A W
RESUMO
Three lactic streptococcal bacteriophages were compared with one another by electron microscopic analysis of heteroduplex DNA molecules. The phages were almost identical in morphology and had been isolated over a period of 10 years on different strains of Streptococcus cremoris from cheese plants situated in different parts of New Zealand. There was a high degree of homology between the DNAs, in agreement with Southern blot hybridization data reported earlier. There were, however, distinct regions of nonhomology, mostly between 0.45 and 1.71 kilobases in length, suggestive of the occurrence of block recombination events. A deletion of 2.23 kilobases in the two more recently isolated phages, or an insertion in the first isolate, was found. All three phage DNAs showed differences in restriction endonuclease cleavage sites. Alignment of the restriction endonuclease maps with the heteroduplex maps showed that differences in cleavage sites occurred most frequently in regions of nonhomology. However, differences in cleavage sites in regions of apparent homology were also detected, indicating that point mutations may have occurred in addition to block recombination events.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=238920Documentos Relacionados
- Detailed Characterization and Comparison of Four Lactic Streptococcal Bacteriophages Based on Morphology, Restriction Mapping, DNA Homology, and Structural Protein Analysis
- Restriction endonuclease cleavage analysis of herpes simplex virus isolates obtained from three pairs of siblings.
- Restriction endonuclease cleavage map of the DNA of JC virus.
- Characterization of Chlamydia DNA by restriction endonuclease cleavage.
- Characterization of Temperate Bacteriophages of Bacillus subtilis by the Restriction Endonuclease EcoRI: Evidence for Three Different Temperate Bacteriophages