The SCN9A gene encodes the Nav1.7 sodium channel protein, which is primarily expressed in the sensory and sympathetic nerves of the peripheral nervous system and is highly expressed in the dorsal root ganglia. Nav1.7 sodium channels play a crucial role in transmitting positively charged sodium ions within cells, which are essential for generating and transmitting electrical signals. When a person experiences pain, this protein releases sodium ion currents that amplify and stimulate nerve cells, sending electrical signals to the brain, thereby causing the sensation of pain. The SCN9A gene guides the entry of sodium ions into cells and facilitates communication between neurons. Mutations in the SCN9A gene can alter the function of sodium channels in the brain, disrupting neuronal communication and leading to various pain, olfactory, and neurological disorders such as erythromelalgia, paroxysmal extreme pain disorder, Dravet syndrome, small fiber neuropathy, and congenital insensitivity to pain. The abnormal protein function and symptoms resulting from gene mutations are directly related to the severity of the mutations, and different mutation types may lead to completely different conditions. SCN9A is an excellent target for analgesic drug development. Downregulation of SCN9A expression can alleviate acute pain as well as certain types of inflammatory and neuropathic pain ^[1]. OliPass Corporation, a South Korean biotechnology company, has developed an antisense peptide nucleic acid (PNA) analgesic targeting SCN9A (OLP-1002), which has entered Phase 2a clinical trials. Antisense PNA is an artificially synthesized DNA/RNA mimic that inhibits RNA/DNA transcription and translation by complementary pairing with RNA/DNA sequences. The drug has shown strong analgesic effects and prolonged therapeutic duration in Australian patients with moderate to severe chronic osteoarthritis pain. It is estimated that due to its potent efficacy, excellent safety profile, and broad therapeutic scope, OLP-1002 could generate over $50 billion in market potential annually ^[2-4]. The B6-hSCN9A mouse is a mouse Scn9a humanized model, generated by replacing the mouse Scn9a gene (including the 5' UTR and 3' UTR) with the corresponding human SCN9A gene sequence using gene editing technology. Internal research revealed that during the generation of B6-hSCN9A mice, the murine Scn9a gene was inserted unexpectedly, and its precise genomic insertion site remains undetermined*. This strain is suitable for studying the pathogenic mechanisms of neurological diseases such as erythromelalgia, Dravet syndrome, small fiber neuropathy, and congenital insensitivity to pain, as well as for screening analgesic drug candidates. In addition, based on the independently developed TurboKnockout fusion BAC recombination technology, Cyagen can also provide customized services. * Special notes on the genotype of B6-hSCN9A mice: B6-hSCN9A het: 1 copy of hSCN9A + 2 copies of mScn9a; B6-hSCN9A homo: 2 copies of hSCN9A + 2 copies of mScn9a.

The SCN9A gene, which encodes the voltage-gated sodium channel protein Nav1.7, is an important pathogenic factor underlying peripheral neuropathic pain and related rare diseases. Nav1.7 sodium channels mediate the influx of positively charged sodium ions into cells and play a critical role in the generation and propagation of action potentials. Studies have shown that genetic variants in SCN9A are closely associated with multiple inherited pain disorders, including erythromelalgia, small fiber neuropathy, and congenital insensitivity to pain ^[1-2]. As a voltage-gated sodium channel, the Nav1.7 protein is predominantly expressed in sensory and sympathetic neurons of the peripheral nervous system, with particularly high expression in dorsal root ganglia, where it plays an essential role in the generation and transmission of pain signals ^[3]. Research indicates that down-regulation of SCN9A expression or selective inhibition of Nav1.7 holds promise as a novel and highly effective analgesic strategy for the treatment of acute, inflammatory, and neuropathic pain ^[4]. Currently, drug development targeting SCN9A/Nav1.7 continues to advance and encompasses multiple modalities, including small-molecule inhibitors, epigenetic regulation, gene therapy, and biologic agents. Several companies have established relevant pipelines; for example, raxatrigine from GSK has entered Phase III clinical trials for trigeminal neuralgia, while Xenon Pharmaceuticals, Vertex Pharmaceuticals, and others are actively progressing selective Nav1.7 inhibitors in preclinical and early clinical stages ^[5]. hSCN9A(SD) rat is a humanized Scn9a model generated by gene-editing technology. The coding sequence of exon 2 to partial intron 7 of rat Scn9a was replaced with the Kozak-Human SCN9A CDS-3'UTR of Human SCN9A-WPRE-BGH pA cassette. This model can be used for investigating the pathogenic mechanisms of inherited pain disorders such as erythromelalgia, small fiber neuropathy, and congenital insensitivity to pain, as well as for the preclinical research, screening, and evaluation of Nav1.7-targeted analgesic candidates.

Ttc22 is located on chromosome 4 of mice. Nuclease Technology was used to design sgRNA; Ttc22 knockout mice were obtained by applying high-throughput electroporation of fertilized eggs. After sexual maturity, sperm were collected for cryopreservation.

Tln1 is located on chromosome 4 of mice. SgRNA and ssDNA will be designed using Nuclease Technology; Tln1 conditional knockout mice will be obtained by high-throughput electroporation of fertilized eggs. After sexual maturity, sperm will be collected for cryopreservation.