Chemical Exposure Generates DNA Copy Number Variants and Impacts Gene Expression

Figure 1

Toxicity assays interrogating DNA sequence alterations by size. Classic cytogenetic methodologies routinely identify whole genome, whole chromosomal, and microscopic structural chromosomal aberrations. At the opposite end of the spectrum, mutation assays are optimized to detect single base pair mutations. Development of genome-wide technologies including array-based assays (e.g., array CGH) and whole genome sequencing now permit efficient detection of DNA structural alterations of an intermediate size including copy number alterations and enable direct integration with a reference genome sequence. As a result, the ability of chemical exposure to induce this type of DNA alteration was not thoroughly investigated in the past and is just now beginning to be addressed.