Dorso-ventral axis perturbation in goldfish embryos caused by heat- and pressure-shock treatments for chromosome set manipulation.

Effects of the chromosome set manipulation on early embryonic development were examined in goldfish and crucian carp. Both pressure- and heat-shock treatments of fertilized eggs induced developmental disorders such as thin blastodisc formation, delay of epiboly, and deficiency of dorso-anterior structures. The longer the treatments were applied to the eggs, the more frequently severe dorsal deficiencies were induced in the embryos. No and reduced signals of goosecoid mRNA, a dorsal mesodermal marker, were observed in embryos treated with heat-shock at 40°C for 1 min at 5 min postfertilization. These results suggested that such treatments should affect not only the retention of the second polar body, but also the suppression of dorso-ventral differentiation. [ABSTRACT FROM AUTHOR]