Retention of mitochondrial DNA species in somatic cell hybrids using antibiotic selection.

Interspecific cell hybrids were constructed by fusion of an antimycin-resistant, thymidine kinase- (TK-) Chinese hamster cell line with a chloramphenicol-resistant, hypoxanthine-guanine phosphoribosyl transferase- (HPRT-) mouse cell line. Hybrids were selected in HAT medium alone, or HAT supplemented with chloramphenicol, antimycin, or both antibiotics. Analysis of the mitochondrial DNA (mtDNA) of these hybrids indicates that antibiotic selection directed at the mitochondrial populations results in retention of the resistant parental genome and loss of the sensitive parental genome.