Genomic Alteration of Bisphenol A Treatment in the Testis of Mice

Bisphenol A (BPA) is commonly used in the production of pharmaceutical, industrial, and housing epoxy, as well as polycarbonate plastics. Owing to its extensive use, BPA can contaminate the environment either directly or through derivatives of these products. BPA has been classified as an endocrine disruptor chemicals (EDCs), and the primary toxicity of these EDCs in males involves the induction of reproductive system abnormality. First, in order to evaluate the direct effects on the Y chromosome associated with reproduction, we evaluated Y chromosome abnormalities using a Y chromosome microdeletion detection kit. However, we detected no Yq abnormality as the result of BPA exposure. Secondly, we performed high-density oligonucleotide array-based comparative genome hybridization (CGH) to assess genomic alteration as a component of our toxicity assessment. The results of our data analysis revealed some changes in copy number. Seven observed features were gains or losses in chromosomal DNA (P-value<1.0e-5, average log2 ratio>0.2). Interestingly, 21 probes of chr7:7312289-10272836 (qA1-qA2 in cytoband) were a commonly observed amplification (P-value 3.69e-10). Another region, chr14:4551029-10397399, was also commonly amplified (P-value 2.93e-12, average of log2 ratios in segment>0.3786). These regions include many genes associated with pheromone response, transcription, and signal transduction using ArrayToKegg software. These results help us to understand the molecular mechanisms underlying the reproductive effects induced by BPA.