Abstract: Objective To explore the relationship between the expression of Dishevelled2 and Vangl2 and the embryonic neural tube defects (NTDs) induced by all-trans retinoic acid (RA)in Kunming mouse. Methods Fifty pregnant mice were randomly divided into control and RA-treated groups．RA-treated mice were fed with 30mg/kg RA dissolved with peanut oil on embryo 7.75 days, while the mice of control group were administrated with an equal volume of peanut oil on the same time. Then all the embryos were sampled from pregnant mice at the 4th, 18th, 42nd, 66th and 90th hour after treatment. EM>In situ/EM> hybridization and immunohistochemical staining technique were used to detect the expression of Dishevelled2 and Vangl2 in embryonic neural tube. Results The two proteins both existed in the epithelial tissue of the mouse embryonic neural tube and displayed different expression modes at various developmental stages.Compared with the control group， the RA treated group showed a significant decrease (P≤0.05) at the 18th and 42nd hour and a significant increase (EM>P/EM>≤0.05) at the 66th hour in Dishevelled2 protein after maternal treatment, and no significant difference was found at the 90th hour. Compared with the control group, the Vangl2 mRNA expression in the RA treated group displayed a significant decrease (EM>P/EM>≤0.05) at the 4th and 18th hour and a significant increase EM>(P/EM>≤0.05) at the 66th hour after RA treatment, and no difference was found at the 42nd hour. Compared with the control group, the expression of Vangl2 protein in the RA treated group decreased (P≤0.05) at the 18th and 42nd hour, and increased (EM>P/EM>≤0.05) at the 90th hour after RA treatment, no difference was found at the 66th hour. Conclusion Excessive RA may interfe

Key words: Retinoic acid, Neural tube defect, Dishevelled2, Vangl2, EM>In situ/EM> hybridization, Immunohistochemistry, Mouse 