The OLIG2 gene encodes Oligodendrocyte Transcription Factor 2, a basic helix-loop-helix (bHLH) transcription factor crucial for central nervous system development. It is primarily expressed in restricted domains of the brain and spinal cord ventricular zone, giving rise to oligodendrocytes and specific types of neurons, particularly motor neurons and interneurons. OLIG2 plays a vital role in determining cell fate, promoting the differentiation of oligodendrocyte precursors and motor neurons, and later, supporting oligodendrocyte formation and myelination. Beyond its developmental functions, OLIG2 is broadly expressed in various types of brain tumors, especially diffuse gliomas like astrocytomas, oligodendrogliomas, and oligoastrocytomas, serving as a useful diagnostic marker. Associated diseases include Down syndrome, where altered OLIG2 expression may contribute to cognitive defects, and various cancers beyond glioma and leukemia (e.g., breast cancer, melanoma), where its overexpression is sometimes observed. Olig2-iCre mice were generated using gene editing technology to integrate an IRES-iCre expression cassette into the 60-100 bp downstream of the stop codon of the mouse endogenous Olig2 gene. Under the control of the Olig2 gene's regulatory elements, the iCre recombinase (a codon-optimized Cre recombinase) is expressed. When Olig2-iCre mice are crossed with mice containing loxP sites, Cre recombinase-mediated sequence recombination between loxP sites is expected to occur in Olig2-positive cells of the offspring.

Olig2 is located on chromosome 16 of mice. SgRNA and ssDNA will be designed using Nuclease Technology; Olig2 conditional knockout mice will be obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm will be collected for cryopreservation.