The Paired Related Homeobox 1 (PRRX1/PRX1) gene is primarily expressed in the mesoderm during embryonic development and in mesenchymal tissues in adults. During embryogenesis, the PRX1 gene is highly expressed in the mesenchyme of the face and limbs, as well as in pre-cartilage elements. In adults, this gene is also expressed in skeletal muscle, the heart, and the uterus. The H11-Prrx1-CreERT2 mouse is a tamoxifen-inducible Cre mouse, where CreERT2 recombinase is expressed under the control of the mouse Prrx1 promoter. Without tamoxifen treatment, CreERT2 recombinase remains in the cytoplasm. Upon tamoxifen treatment, CreERT2 recombinase enters the nucleus to perform its recombination function. When H11-Prrx1-CreERT2 mice are crossed with mice carrying loxP sites, tamoxifen induction is expected to cause Cre recombinase-mediated loxP site recombination in the facial and limb mesenchyme, as well as pre-cartilage elements, of the offspring.

Siglec1 is located on chromosome 2 of mice. SgRNA and ssDNA were designed using Nuclease Technology; Siglec1 conditional knockout mice were obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Prrx1 is located on chromosome 1 of mice. Nuclease Technology was used to design sgRNA; Prrx1 knockout mice were obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Mir34a is located on chromosome 4 of mice. Nuclease Technology will be used to design sgRNA; Mir34a knockout mice will be obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Prrx1 is located on chromosome 1 of mice. SgRNA and ssDNA will be designed using Nuclease Technology; Prrx1 conditional knockout mice will be obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm will be collected for cryopreservation.