Scx-P2A-iCre Mouse

Scx (Scleraxis) is a basic helix-loop-helix (bHLH) transcription factor that plays critical regulatory roles during the development of tendons, ligaments, heart valves, and certain mesenchymal tissues ^[1-3]. Scx is primarily expressed in tenocytes, ligament cells, and mesenchymal progenitor cells, where it regulates the expression of extracellular matrix-related genes such as Col1a1 and participates in biological processes including tendon formation, tissue remodeling, and injury repair ^[2-4]. Studies have shown that Scx functionally interacts with multiple development- and fibrosis-associated factors, including Smad3, Mkx, Sox9, Runx2, and the Tgfb family, and plays important roles in heart valve development, myocardial fibrosis, and musculoskeletal injury repair ^[3-5]. Previous studies have also demonstrated that aberrant Scx expression may lead to mesoderm developmental abnormalities, impaired tendon formation, and skeletal-related defects ^[5].

Scx-P2A-iCre mice were generated by replacing the endogenous Scx stop codon with a P2A-iCre cassette, enabling the expression of codon-optimized iCre recombinase under the control of endogenous Scx regulatory elements. When crossed with mice containing loxP sites, Cre-mediated recombination between loxP sites is expected to occur in Scx-positive cells of the offspring.