Simple numerical descriptor for quantifying effect of toxic substances on DNA sequences

Many chemicals are known to be toxic to living organisms, inducing mutation s and deletions at the chromosomal and genetic level. One of the tasks in r isk assessment of genotoxic chemicals is to devise a simple numerical descr iptor which may be used to quantify the relationship between chemical dose and the effect on the genetic sequences. We have developed numerical descri ptors to characterize different DNA sequences which are especially useful i n sequence comparisons. These descriptors have been developed from a graphi cal representational technique that enables easy visualization of changes i n base distributions arising from evolutionary or other effects. In this pa per we propose a scheme to use these descriptors as a label to help quantif y the potential risk hazard of chemicals inducing mutations and deletions i n DNA sequences.