Arsenic-induced changes in gene expression in the neural tube of Folr2-/- KO mouse embryos. Mus musculus

In order to more thoroughly investigate the mechanism of arsenate-induced NTDs we designed experiment in which highly sensitive Folr2 nullizygous mice were treated i.p. with teratogenic dose of sodium arsenate just at the beginning of the neural tube formation process. This specific knockout mouse and arsenic exposure conditions were chosen as they warranted high incidence of exencephaly in exposed embryos. We investigated the gene expression changes induced by arsenic in the anterior part of neural tube in order to discover patterns that might shed light on the mechanism of arsenic’s teratogenicity. Keywords: toxic response Overall design: On GD 7:12 and 8:12, pregnant Folr2-/- KO dams were injected ip with water solution of sodium arsenate at the dose of 9.6 mg As/ kg of body weight(treated) or with water for injection only (control). At three selected time-points: 8:15 (3 hours post-injection), 9:00 (12 hours post-injection) and 9:12 (24 hours post-injection), at least 4 control and arsenic treated dams were sacrificed and embryos harvested. From these embryos, the anterior part of neural tube was dissected and RNA extracted. No less than 6 embryonic neural tubes (3controls and 3 arsenic treated) for each time-point were used for hybridization on commercially available CodeLink UniSet 10K Bioarray. Together, 22 control and treated samples at above mentioned, 3 selected time-points were used in this study