NTDs and TEM studies of brains of E10.5 embryos. (A) Representative E10.5 tie1-cre/survivin^lox/lox embryo (−/−) with exencephaly (arrow). Scale bar indicates 1 mm. (B-C) Sagittal sections of the head of E10.5 embryos stained for H&E, showing exencephaly (arrows) in −/− embryo. (D-H) Survivin^lox/lox (+/+) and tie1-cre/survivin^lox/lox (−/−) embryo sections were examined by EM. Neural cells with mitotic figures (arrows in panels E-F) or apoptotic bodies (arrows in panels G-H) were frequently seen in the hindbrains of −/− embryos but not in those of +/+ (D) embryos. Scale bar indicates 2 μm for panels D-H.