Production of Achondroplasia in the Chick Embryo with Thallium.

Summary Thallium sulfate produces a consistent and severe degree of achondroplasia in the chick embryo when injected on the fourth day of incubation. This abnormality appears to be similar to the genetic, and to some of the nutritional deficiency, types of chondrodystrophy. Thallium induced achondroplasia is not prevented by treating the embryo with manganese, biotin, nicotinamide or riboflavin, deficiencies of which have been reported to result in some type of chondrodystrophy in the chick embryo.