title: Molecular cloning and restriction endonuclease mapping of the rat cytomegalovirus genome.
abstract: Rat cytomegalovirus (RCMV) DNA was cleaved by restriction endonuclease EcoRI into 24 fragments ranging in mol. wt. from 34 X 10(6) to 0.20 X 10(6), of which 18 fragments could be cloned in plasmid pACYC 184. Restriction endonuclease XbaI cleaved the RCMV genome into 28 fragments, ranging in size from 44 X 10(6) to 0.81 X 10(6), of which 24 fragments were cloned in plasmid pSP62-PL. Among the restriction fragments that could not be cloned were two major terminal colinear fragments, EcoRI-A (34 X 10(6)) and XbaI-A (44 X 10(6)). Thus, the complete sets of recombinant plasmids spanned about 70% of the RCMV genome. Our mapping results including determination of the termini of the genome, characterization of double digestion products of restriction fragments and cross-hybridization of 35S-labelled (cloned) EcoRI and XbaI fragments to Southern blots of EcoRI-, XbaI- or BglII-cleaved RCMV DNA, allowed us to construct the EcoRI and XbaI restriction maps of RCMV DNA. Since no cross-hybridization between internal fragments was seen, it is concluded that the RCMV genome consists of a long unique sequence of 224 kilobases without internal inverted repeat sequences, which is similar to the structures of murine and guinea-pig CMV DNA but unlike that of human CMV DNA. In a minor population (approx. 20%) of the RCMV DNA, one terminus was found to be larger by 0.35 X 10(6) mol. wt. The nature of this fragment is unclear at the moment.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D003587:Cytomegalovirus / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D015246:Deoxyribonuclease EcoRI; D015252:Deoxyribonucleases, Type II Site-Specific; D005814:Genes, Viral; D051381:Rats
chemical_list: D004279:DNA, Viral; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; C025580:endodeoxyribonuclease XBAI; D015252:Deoxyribonucleases, Type II Site-Specific