Fig. 1.

NTDs in E10.5 mouse embryos exposed to BaP (A) Control E10.5 embryo; (B-D) E10.5 embryos exposed to BaP with NTDs; (B) Embryo with closure failure in the brain (arrow); (C) Embryo with unfused neural folds resulting in anencephaly (arrow); (D) Embryo with exencephaly near the midbrain (arrow); (E and F) H&E staining of the control and NTD embryos, closed neural tube (E) and open neural plate (F) are indicated by arrows, sectioned along the plane indicated by the white line in A and B, respectively; (G) NTD subtype distribution of E10.5 mouse embryos exposed to BaP. Embryos treated with BaP from E6.5 were found mainly with unfused neural folds at mid and hindbrain, while embryos in E7 exhibited anencephaly with neural folds unfused at forebrain. fb, forebrain; mb, midbrain; hb, hindbrain.