Tmem119-CreERT2 Mouse

The TMEM119 gene encodes transmembrane protein 119 (TMEM119), also known as osteoblast-inducing factor (OBIF). It acts as an oncogene in osteosarcoma and is highly expressed in microglia. This ubiquitously expressed protein plays critical roles in various biological processes, including cell adhesion, migration, and differentiation. The TMEM119 gene encodes transmembrane protein 119 (TMEM119), also known as osteoblast-inducing factor (OBIF). It acts as an oncogene in osteosarcoma and is highly expressed in microglia. This ubiquitously expressed protein plays critical roles in various biological processes, including cell adhesion, migration, and differentiation. TMEM119 is vital for osteoblastogenesis—the differentiation of mesenchymal stem cells into bone-forming osteoblasts. It interacts with key signaling molecules like bone morphogenetic proteins (BMPs) to regulate osteoblast proliferation and differentiation, ultimately promoting bone formation and remodeling. Notably expressed in the developing nervous system, TMEM119 enhances neurite outgrowth and neuronal survival. It interacts with extracellular matrix components and growth factor signaling pathways to support the complex processes of neural network formation and function. Beyond its roles in bone formation and neurodevelopment, TMEM119 is also essential for normal spermatogenesis and late-stage testicular differentiation.

The Tmem119-CreERT2 mouse is generated via gene-editing technology by integrating a tamoxifen-inducible CreERT2 recombinase cassette into the stop codon of the murine Tmem119 gene, thereby driving its specific expression. This construction strategy ensures that the expression pattern of CreERT2 recombinase mimics that of the endogenous murine Tmem119 gene. Before tamoxifen induction, CreERT2 is confined to the cytoplasm; only after tamoxifen treatment can CreERT2 recombinase translocate into the nucleus to exert its genetic recombination function. When this strain is crossed with mice containing loxP sites, tamoxifen induction triggers Cre-mediated sequence recombination between loxP sites specifically in microglia. Tmem119-CreERT2 mice are applicable for researching the functions of resident microglia in the central nervous system, as well as bone development, osteoblast differentiation, and osteosarcoma.