Skeletal defects in embryonic chicks induced by administration of beta‐aminopropionitrile

Teratogenic skeletal defects were produced when beta‐amino‐propionitrile (BAPN) was injected onto the chorioallantoic membrane of 7‐day chick embryos at doses between 0.156 and 1.25 mg BAPN/embryo. The mandible became bent and buckled, the upper jaw shortened, and the tibia and fibula bent into an S‐shaped configuration. Apparently the weakened bone was unable to withstand normal growth pressures. Massive osteogenesis was initiated on the concave surface of the bent tibia forming an exostosis. The histology and histochemistry of these bones were described.