Jan Vijg

DNA methods for detecting and analyzing mutations in vivo

a.b The major adverse health effects in man attributable to exposure of somatic and germ cells to carcinogens and/or mutagens are tumor formation and, possibly, induction of heritable diseases. In addition, the biological process of aging has been suggested to be caused by the cumulative effects of the continuous exposure to low levels of

New Methods for Detecting DNA Sequence Variation in Relation to Aging

The availability of accurate and sensitive methods for the detection of DNA sequence variation is an important prerequisite for obtaining insight in the genetics of aging. DNA sequence changes in somatic cells are considered as causal factors in aging, while the accumulation in the germ line of late-acting deleterious mutations could underly the genetic component of age-related disorders, such as Alzheimer disease. We have taken two new experimental approaches for studying DNA sequence variation in genomic DNA from higher animals. First, we have used transgenic mice harboring a number of tandemly integrated shuttle vectors with a lacZ bacterial marker gene for measuring both spontaneous and induced mutations in various organs and tissues. Second, by using a two-dimensional electrophoretic separation system (size-separation in neutral gels, followed by denaturing gradient polyacrylamide gel separation on the basis of sequence content) we have been able to detect minute variations in minisatellite and simple sequences. The use of these novel experimental systems in studying the molecular basis of aging will be discussed.