[Generation and characterization of chondrocyte specific Cre transgenic mice]

A chondrocyte specific transgenic construct (pcol2A1-Cre) containing the cartilage specific type II collagen A1 promoter, the Cre recombinase gene and the polyA of human growth factor gene was generated. The 9.3 kb DNA fragments were recovered from Not I digested fragments and microinjected into 323 fertilized eggs. The injected eggs were implanted into the oviduct of 14 female mice. In the 52 offsprings, there were 10 mice carring the transgene identified by PCR, and the efficiency was 19.2%. The col2A1-Cre transgenic mice were crossed with a conditional gene targeting mice to check the Cre mediated recombination in multiple tissues. The results of the PCR analysis suggested that the Cre recombinase was expressed only in cartilaginous tissue and could mediate the recombination between the LoxP sites in vivo. The result was further confirmed by Southern-blot.