Quantitative PCR reveals preferential nuclear DNA alkylation by epichlorohydrin in the chicken genome

Adam Newman, Colby College

Document Type Honors Thesis (Open Access)

Abstract

Epichlorohydrin (ECH) is a DNA bifunctional alkylating agent that has been shown to form DNA inter-strand cross-links in vitro at the N7 position of guanines at the 5'-GNC and 5'-GC consensus sequences. We used the quantitative polymerase chain reaction (QPCR) to monitor the formation of in vivo ECH lesions in 6C2 chicken erythroid progerutor cells. Three distinct loci were investigated in order to determine the effect of ECH reactivity in different levels of chromatin condensation. The sites consisted of an open locus of the nuclear genome, a closed locus of the nuclear genome, and a naked locus of the mitochondrial genome. We found that ECH alkylation was preferentially targeted towards the nuclear sites and that chromatin structure had no effect upon ECH reactivity. Repair assays of the three sites revealed that there appears to be no repair of ECH lesions in the nuclear genome.