An autoradiographic study of the generation cycle in the ten-day mouse embryo neural tube

An autoradiographic study of the generation cycle in the 10-day-old mouse embryo neural tube shows a total generation time of 8.5 hr, and a DNA synthetic period of approximately 4.0 hr. Though growth appears to be almost exponential over the early part of the time studied, increasing migration and differentiation of labeled cells becomes evident towards the end of the observation period. Between day 10 and day 11, the mean Ts increases by approximately 1 hr. This increase in the S period appears to correlate with the transition between the phase of predominate cell proliferation in the 10 day neural tube and accelerated migration and differentiation of the 11 day neural tube.