The Effect of Chloroacetophenone on Chick Embryos Culturedin vitro

ABSTRACT The effect of chloroacetophenone (0·0005 M), which has been described as a powerful and irreversible —SH reactant, has been studied on chick embryos cultured in vitro at the primitive-streak and head-process stages. Abnormalities were produced predominantly in the brain region, and included improper differentiation, partial or complete non-closure, and defective lumen. Neural tubes were irregular and open. Shortening of the axis was also common. Embryos at the head-process stage were not affected by the substance at the concentration used. The effect of the chemical on the morphogenesis of the chick embryo is discussed.