Teratogenic effects of methyl parathion in developing chick embryos

The effect of methyl parathion (MP) on developing chick embryos was investigated. The embryos were exposed at different stages of development to various doses of MP via the yolk sac route. This resulted in retarded growth which included reduced body weight and reduced body length and length of leg bones. Other teratogenic signs observed were short neck, muscular hypoplasia of legs, abdominal hernias and haemorrhagic spots in brain and upper body. These findings suggest that MP was a teratogen when injected into the yolk sacs of developing embryos.