Teratism induced in the developing chick by RPR-V, an organophosphate

Fertile White Leghorn chicken eggs were injected on day 4 of incubation with 0, 0.25, 0.50 or 1.00 mg RPR-V/egg and opened on day 20 or allowed to hatch. The following parameters were examined: hatchability, growth and development, external malformations and skeletal deformities. As the dose was increased, the hatchability decreased, and the incidence of deformities increased. Staining of the skeleton with Alizarin red showed clear deformities in the embryos. The results suggest that RPR-V has teratogenic effects on chick embryos when injected on day 4 of incubation.