Novel effects of folinic acid supplementation in embryonic zebrafish, danio rerio

Abstract

Although periconceptional folate supplementation has lead to a decrease in the incidence of neural tube defects (Rosano et al., 1999), studies suggest that there is also a relationship with the increased incidence of autism spectrum disorders (Beard et al., 2011). The purpose of the current study was to examine the effect of folinic acid (FA) on embryonic development. Adult zebrafish, Danio rerio, were maintained using standard procedures and breed in house. After light onset, embryos were sorted into either FA (10 mM for 24 hrs) or Control. Assessments (time to hatch, gross morphology, startle response (SR), and development of swim behavior (ST)) were made at 2, 3, and 5 DPF. FA was found to alter the timing of development, with an increase in the percentage hatched prematurely to 2 DPF. Embryos were also found to be smaller at 3 DPF (M = 3.22, SD = 0.26) than the control (M = 3.37, SD = 0.19). However, by 5 DPF the FA group had larger overall body size (FA: M = 3.67, SD = 0.17 Control: M = 3.46, SD = 0.20). While both SR and ST behaviors were similar at 3 DPF, at 5 DPF the FA had lower swim time (higher anxiety). The obtained results indicate that FA exposure had an effect on both anatomical developmental and locomotor behavior. Embryos exposed to FA hatched approximately 24 hours before the control group and showed higher level of anxiety in both the startle response and swim behavior.