By analyzing the hearts of quail-chick chimeras, it was found that neural crest cells at the level of occipital somites 1 to 3 migrate to the region of the aorticopulmonary septum. Bilateral removal of this neural crest population prior to migration causes malformation of the aorticopulmonary septum resulting in common arterial outflow channels or transposition of the great vessels.

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Previous studies have shown that cadmium induces a variety of grossly detectable malformations in the golden hamster including exencephaly, cleft lip and palate, amelia, micromelia and ectrodactyly. This report presents the frequency and types of underlying skeletal malformations induced by the intravenous administration of cadmium at four times during the critical stages in hamster embryo organogenesis. In general, all areas of the skeletal system are damaged by this heavy metal. This is manifested by the absence or poor development of ossification centers in different bones. Possible mechanisms of action of cadmium are discussed.

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