This allele is a derivative of Mecp2tm1Jae in which exon 3 is deleted by Cre mediated recombination in a germline transmissible event. Mice carrying Mecp2tm1Jae were mated to transgenic mice carrying a cre transgene under the control of a nestin promoter. This promoter was active in the male and female germline as well as the brain, and progeny of the cross were screened for deletion of exon 3. (J:67909)