The Avian Embryo: A Developmental Research Tool

Abstract

The importance of the chick embryo in embryological research is well known. Several authors have pointed out its applicability, advantages and usefulness in developmental biology, experimental embryology and teratology. The chicken embryo is a proven animal model to screen drugs for their teratological potential. Test solution is applied through a small hole drilled into the shell above the air sac. This method reduces the mortalities associated with piercing the vitelline membrane. Volumes of up to 50 ¹ l can be administered directly onto the vitelline vessels for rapid absorption. Several experimental groups can thus be treated quickly and ef ciently with various concentrations of the drug of interest. Detailed analysis of the effects on a speci c stage or structure is possible by terminating development at that particular stage. Allantoic and amniotic uids can be aspirated and analysed for speci c metabolic products or markers. From the results it is apparent that chemical interference is more recurrent in the development of certain structures as some effects, like ectopia cordis and retarded growth, are seen repeatedly, irrespective of the substance tested. The effects may or may not be dose dependent. In conclusion, our results indicate that the developing chick embryo is indeed a valid and sensitive developmental research tool in a well-controlled experimental environment.