Nucleotide changes in mitochondrial 16S rRNA gene from different mammaliancell lines

The partial nucleotide sequences of mitochondrial 16S rRNA gene were analyz ed in five rodent cell lines, prior to the analysis of mutation spectrum in the gene. Total DNA was isolated from V79 and CHO-K1 cell lines from Chine se hamster and murine cell lines, Balb Y SV and PCC4 AG Cap, and the 3' ter minal regions including the peptidyl transferase domain which is the target for chloramphenicol, a selective inhibitor of mitochondrial protein synthe sis, were amplified by polymerase chain reaction (PCR) using two sets of pr imers and directly sequenced. In Chinese hamster cells, C to T transition a t one site was observed in CHO-K1, and either A was deleted at the sequence of AA in all three cell lines, relative to the V79-cell sequence registere d in GenBank. One G to A transition mutation in heteroplasmic state was obs erved in mouse PCC4 AG Cap cells which have chloramphenicol resistant pheno type, whereas there was no change in the Balb Y SV cell line, relative to t he L-cell sequence. These mutation sites were located outside the peptidyl transferase domain.