Prolonged developmental arrest precludes subsequent embryogenesis.
Sets of 25-30 eggs were maintained at 15.5deg.C for various numbers of days as indicated, then transferred to 37deg.C and incubated for 10 days. On E10, eggs were opened and visually inspected for signs of embryogenesis. Embryos either looked normal or were dead. Embryo viability was scored as the number of live embryos divided by the total number of eggs, multiplied by 100. Data are reported as means +/- SEM of percent viability for several egg sets subjected to the various days of arrest as indicated in the figure. Arrest periods greater than 7 days severely suppressed subsequent embryogenesis.