Fig. 1. Conditional removal of Smo activity in chondrocytes. (A) Schematic of the wild-type Smo allele (Smowt) and the conditional allele (Smoc). Below is a representative Southern blot identifying the targeted allele. Following EcoRV digestion, the 5' probe detects bands of 13 kb and 9 kb from wild-type and Smoc alleles, respectively. After BamHI digestion, the 3' probe detects bands of 9.6 kb and 7.2 kb from wild-type and Smoc alleles, respectively. (B) Organization of the Col2-Cre transgene. G.S.S., ß-globin splicing sequence. Below are whole-mount X-gal staining of E12.5 embryos that carry each of the three independently generated Col2-Cre transgenes (15, 3 and 10), and a Rosa26-LacZ reporter allele that requires Cre-mediated recombination for lacZ expression (see text).
