Analysis of cadmium chloride effect on the fidelity of in vitro DNA synthesis

Gertie Locklear-Mariani, Fayetteville State University


The present study investigated the mutagenic effect of cadmium chloride, a known carcinogen, on the fidelity of DNA synthesis. The hypothesis that CdCl2 would reduce the fidelity of in vitro DNA synthesis and that the effect is dose dependent was tested. An in vitro fidelity assay, the M13mp2LacZ $\alpha$-complementation assay was used in this analysis. A concentration range of 0.1 mM to 2.0 mM CdCl$\sb2$ was used to determine the effect of CdCl$\sb2$ on the induction of mutations during synthesis of a 250 base target region of DNA. Analysis of reaction products indicated that CdCl$\sb2$ inhibits gap-filling DNA synthesis by exonuclease-deficient E. coli DNA polymerase I (Klenow fragment) at concentrations greater than 0.4 mM. Complete gap-filling synthesis was obtained in the CdCl$\sb2$ range of 0.1 to 0.4 mN. Results from analysis of DNA synthesis products indicated that at these concentrations CdCl$\sb2$ is not mutagenic and, in fact, demonstrated a slight anti-mutagenic effect. These results are consistent with published reports showing the Cd$\sp{2+}$ fails to demonstrate a mutagenic effect in other assays done in bacterial systems. The significance of the observed antimutagenic effect may be the subject of future study.

Subject Area

Biochemistry|Chemistry|Molecular biology|Oncology

Recommended Citation

Locklear-Mariani, Gertie, "Analysis of cadmium chloride effect on the fidelity of in vitro DNA synthesis" (1997). ETD Collection for Fayetteville State University. AAI1390616.