Altered Pax6 and gga-miR-365-3P expression in the cerebral cortex of chicken embryo in response to in ovo administration of folic acid; real-time PCR and Western blot analysis

Folate plays an important role in the regulation of genes involved in neurogenesis and synaptic plasticity during brain development. Many genes including Pax6 and miRNAs have been shown to play important roles in brain development. gga-miR-365-3P targets many genes including Pax6. In this project, we aimed to investigate the effects of in ovo administration of folic acid (FA) on the expression of Pax6 and gga-miR-365-3P in the developing chicken cerebral cortex. A total number of 90 embryonated eggs were used in this experiment. Thirty eggs were injected by FA into the yolk sac at a dose of 150 μg per egg, 30 eggs (SHAM) were injected by PBS on embryonic day (E) 11 and 30 eggs were left without injection as a control group. Then the cerebral cortex was collected on E19 and Pax6 and gga-miR-365-3P expression was studied using Real-time PCR and Western blot. The results showed that Pax6 expression in the cortex of FA treated, SHAM and controls were 1.53±0.2, 1.01±0.29 and 0.93±0.12 fold changes, respectively and for gga-miR-365-3P were 0.74±0.1, 0.93±0.1 and 0.99±0.14-fold change, respectively. A higher Pax6 protein expression was observed in FA-treated groups compared to either SHAM or controls by Western blot. No significant changes were observed in Pax6 protein expression between SHAM and controls. It is concluded that in ovo administration of FA increases Pax6 and decreases gga-miR-365-3P expression in the developing chick cerebral cortex. Further studies are needed to elucidate the cellular and molecular mechanisms by which FA affects brain development.