Neural Tube Defect of Chick Embryos by Needle Puncture and Albumen Removal

ABSTRACT

OBJECTIVE: The animal research of embryonic teratogenesis is widely performed and the neural tube defects are also studied through various animal models. Particularly, the experimental research on chick embryos is performed with great popularity. In this experiment we studied the effect of albumen removal and the needle puncture on the development of neural tube defects in chick embryos. METHODS: The domestic hen eggs of control group are incubated for 14 days at 37.5degreesC and 70% humidity. The experimental group was divided into three groups, needle puncture group, 5 cc albumen removal group and 10 cc albumen removal group after the eggs were incubated for 24-28 hours and incubated for another 13 days after the puncture with or without albumen removal. After 14 days of incubation, all the embryos were isolated and morphologically characterized. RESULTS: Of 39 incubated chick embryos in control group, 31 embryos were grown as normal and 8 embryos were grown as anomalous. The numbers of total(normal/anomalous/developmentally arrest) embryos of each group were 37(14/16/7), 37(9/17/11), and 37(6/13/18) in the needle puncture, 5cc albumen removal and 10cc albumen removal groups, respectively. Needle puncture increased the teratogenesis of chick embryos significantly but did not increase the neural tube defect. In cases of 5 cc albumen removal, the teratogenesis of chick embryos was increased to a significant level and the incidence of neural tube defect was increased significantly. In cases of 10 cc albumen removal, not only teratogenesis but also growth arrest were increased markedly. Therefore, it was not considered to be an adequate experimental model. CONCLUSIONS: This results indicate that needle puncture itself to remove the albumen from chick embryos had nothing to do with the neural tube defects and therefore its effect can be excluded. Needle puncture and albumen removal cause not only neural tube defects but other malformations such as abdominal wall defects, developmental arrest, and malformation of eyes.