Figure 1.

Penetrance of phenotypes caused by the Mecp2³⁰⁸ allele. Each of the four panels shows an image of a mutant female mouse and of a wild-type female litter mate (inset). The percentage of animals of each sex manifesting a particular phenotype is shown below each panel. A, Representative image of a female with DF. The inset shows a wild-type litter mate with shiny and groomed fur. B, A picture taken at a shutter speed of 1 s reveals the tremor as a shadow effect over the mouse’s silhouette (arrows). The sharp inset picture of a wild-type mouse was taken at the same shutter speed. C, PLs that sometimes extend to the ears. Note also the disarranged appearance of the fur. Inset shows a normal eye in a wild-type litter mate. D, SFMs, inferred by looking at this picture taken with a shutter speed of 1 s. The arrow points to the forepaws of the mutant female, which have a shadow because of the rapid movements (see video by Shahbazian et al. [2002a] at the Neuron Web site).