This strain expresses a fusion product involving Enhanced Green Fluorescent Protein (EGFP) and Cre recombinase from the endogenous Shh locus. EGFP and cre expression are consistent with the endogenous gene. Fluorescence is detected in the distal posterior region of the limb buds of embryos aged embryonic day 10 to 12 and colocalizes with the endogenous gene product (mRNA). The donating investigator reports that it is not uncommon for a mosaic expression pattern to be exhibited when the allele is inherited through the female germline. It is recommended that this allele be passed through the male germline when conducting experiments involving cre-induced recombination. Mice homozygous for the mutation develop a limited limb skeleton and lack digit 2. Homozygous mice are not viable or fertile. Heterozygous mutant mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. This mutant mouse strain may be useful in studies of limb patterning and development. The Jackson Laboratory 2024, used with permission.