Comparative mutagenesis of human cells in vitro and in vivo. Final progress report, 1 November 1995--31 October 1996

摘要

By combining the separation technology of CDCE (constant denaturing capillary electrophoresis) with high fidelity DNA amplification the authors devised a reliable means to measure mutant fractions of any and all point mutations in human cell or tissue mitochondrial DNA arising at mutant fractions at or above 10 (sup (minus)6). Measurements in nuclear genes are more difficult than in mitochondrial genes. First, the average mutant fractions per base pair in middle-aged human T cells' hprt gene are about 10(sup (minus)8) which is much lower than the approximately 3 (times) 10(sup (minus)6) they have found for mitochondrial point mutations in several human tissues. To see point mutational nuclear hotspots they need an analytical procedure which is reliable at mutant fractions of 10(sup (minus)7) and higher. Fortunately, they are close to that goal. At this writing, reconstruction experiments with human cells indicate they have achieved a sensitivity at least as low as 5 (times) 10(sup (minus)7) so they are optimistic that they can reach the required criterion.