title: Absence of extensive recombination between inter- and intraspecies mitochondrial DNA in mammalian cells.
abstract: Recombination of mammalian mitochondrial DNA (mtDNA) was examined using mouse X rat somatic cell hybrid clones and rat cybrid clones. The mouse X rat hybrids were isolated by fusion of chloramphenicol-sensitive (CAPs) mouse and CAP-resistant (CAPr) rat cells. The rat cybrids were isolated by fusion of rat cells with type B mtDNA and enucleated cells with type A mtDNA. Genetic and physical analyses showed that the mtDNAs of the hybrids and cybrids were simple mixtures of the two parental mtDNAs except in the following two cases: One was subclone H2-9 of mouse X rat hybrids, which was CAPr even though mtDNA from the CAPs mouse parent was predominantly retained. The other was rat cybrid subclones, Y12-24 and -61, which showed specific loss of one Hinf I fragment of type B mtDNA, B10. These observations suggest that, in contrast to the case with plant mtDNA, recombination of mammalian mtDNA occurs rarely, if at all.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002701:Chloramphenicol / Q000494:pharmacology; D002875:Chromosomes / Q000032:analysis; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific; D004351:Drug Resistance; D004591:Electrophoresis, Polyacrylamide Gel; D006822:Hybrid Cells / Q000032:analysis; D008297:Male; D051379:Mice; D051381:Rats; D011995:Recombination, Genetic; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D002701:Chloramphenicol; D004262:DNA Restriction Enzymes; D015252:Deoxyribonucleases, Type II Site-Specific; C032229:GANTC-specific type II deoxyribonucleases