Fig. 6.

Survival rate. a The survival time of Mecp2 ^−/Y rats was plotted in comparison to WT littermates (n = 16). b The 50 % lethality was shown after normalization of the initial rate to 1. c A half of Mecp2 ^−/Y rats died at P63, while 50 % Mecp2 ^−/Y mice dies at P52. d At P52, 50 % mice were survived, while about three fourth of the rats were still alive. e At P63 or the half survival age of Mecp2 ^−/Y rats, only about one third of the mice were still alive. Despite these, no statistical significance was found between rats and mice (d, e)