The specific objective of this contract is to maintain and distribute to the scientific community mouse models for neural tube defects. These models currently include curly tail (ct), splotch (Pax3Sp), delayed-splotch (Pax3S p-d), forebrain overgrowth (fog), apolipoprotein B (Apobtm1Unc), and Twist (Twisttm1Bhr).