| Type | MGI:General | Description | at 14.5-16.5 dpc, ~80% of homozygotes display exencephaly of the entire brain at 14.5-16.5 dpc, exencephalic mutants display undeveloped telencephalic vesicles and diencephalon are surrounded by the everted neuroectoderm of the midbrain and hindbrain; other regions of the neural tube remain unaffected folic acid treatment significantly reduces the exencephalic phenotype both in vivo and in vitro |