Mosaic analysis of dystrophic embryos aggregated with normal chimeras: an approach to mapping the site of gene expression.

Genotypically dystrophic muscle in mouse chimeras of dystrophic leads to and comes from normal genotype has been influenced to develop normally and remain healthy. A significant extramuscular component that effects the expression of the muscle disease in homozygous dystrophic mice is thereby implicated. The potential application of the chimera preparation in further elucidating the source and the nature of that extramuscular influence is outlined.