Sox9-IRES-CreERT2 Mouse

SRY-Box Transcription Factor 9 (SOX9) is a member of the high-mobility group (HMG) superfamily transcription factors encoded by the Sox9 gene. SOX9 is highly expressed in chondrocytes and is also widely expressed in Sertoli cells, genital ridges, kidneys, hearts, and multiple other tissues ^[1-2]. SOX9 is an important master regulatory transcription factor during chondrogenesis and participates in cartilage matrix synthesis and skeletal development through regulating the transcription of cartilage-associated genes, including Col2a1 and Agc1 ^[2-3]. In addition, SOX9 also plays important roles in gonadal development and maintenance of the germ cell microenvironment ^[1,4]. Studies have shown that aberrations in Sox9 are closely associated with skeletal and gonadal developmental disorders, including campomelic dysplasia and sex reversal syndrome. Therefore, SOX9 has been widely used in studies of skeletal development, reproductive development, and regenerative medicine ^[3-4].

Sox9-IRES-CreERT2 mice were generated by knocking a tamoxifen-inducible CreERT2 cassette into the endogenous Sox9 locus. Without tamoxifen, CreERT2 is retained in the cytoplasm; upon induction, it translocates to the nucleus to mediate recombination. When crossed with mice containing loxP sites, Cre-mediated recombination is expected to occur in Sox9-positive cells of the offspring after tamoxifen induction.