title: Application of the deoxyribonucleic acid/ribonucleic acid hybridization technique in Bdellovibrio as a model for studying ribonucleic acid turnover in host-parasite systems.
abstract: The kinetics of host ribonucleic acid (RNA) degradation and its resynthesis into Bdellovibrio-specific polyribonucleotides has been studied. The kinetics of RNA turnover was followed during a one-step synchronous growth cycle of Bdellovibrio growing within 32-po4-Labeled Escherichia coli host cells. The species of labeled RNA present at any given time was ascertained through the specificity of the deoxyribonuclei acid (DNA)/RNA hybridization technique. At nearsaturating levels of RNA and at zero time, 7% of the host DNA sequences and only 0.04% of the Bdellovibrio DNA became hybridized with 32-P-labeled host cell RNA (greater than 99% host specific). At the end of the burst, 98% of the labeled RNA sequences were specific for Bdellovibrio DNA. About 74% of the initial labeled host cell RNA became turned over into Bdellovibrio-specific sequences. We provide data indicating that host cell ribosomal RNA is assimilated by Bdellovibri. Degradation of host cell RNA occurs in a gradual fashion over most of the Bdellovibrio developmental growth cycle. This application of the DNA/RNA hybridization technique and its general concept should be of value in elucidating the kinetics of nucleic acid turnover in other types of host-parasite systems.
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D009693:Nucleic Acid Hybridization; D010761:Phosphorus Radioisotopes; D011119:Polynucleotides / Q000096:biosynthesis; D012329:RNA, Bacterial / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D010761:Phosphorus Radioisotopes; D011119:Polynucleotides; D012329:RNA, Bacterial