• Background: FUS (Fused in Sarcoma) is a multifunctional protein. In the nucleus, it participates in alternative splicing, determining which exons are included or skipped in mRNA transcripts, thus influencing the production of different protein isoforms. It also plays a role in transcription regulation, modulating the expression of various genes. In the cytoplasm, FUS is involved in axonal transport and mRNA stabilization, which are essential for maintaining normal neuronal function. Mutations or loss of function of FUS are strongly associated with ALS (Amyotrophic Lateral Sclerosis). The disruption of FUS-mediated processes causes energy metabolism problems in neurons, abnormal protein aggregation, and ultimately neurodegeneration, contributing to the progressive muscle weakness and paralysis characteristic of ALS.
• Targeting strategy: The exons 4~6 of mouse Fus were knocked out in B-Fus KO mice.
• Validation: The mRNA expression of Fus in heterozygous B-Fus KO mice is approximately half that of the wild-type C57BL/6JNifdc mice, which is consistent with the expected expression levels in heterozygous knockout mice.
• Application: This strain is a Fus knockout mouse model, which can be used for research on the target mechanism and pathological aspects of ALS.

Gene targeting strategy for B-Fus KO mice. The exons 4~6 of mouse Fus were knocked out in B-Fus KO mice.

mRNA expression analysis of Fus in wild-type C57BL/6JNifdc mice and heterozygous B-Fus KO mice by RT-qPCR. Brain and spinal cord RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and heterozygote B-Fus KO mice (+/-) (male, 5-week-old, n=3). The mRNA expression of Fus in heterozygous B-Fus KO mice is approximately half that of the wild-type C57BL/6JNifdc mice, which is consistent with the expected expression levels in heterozygous knockout mice. Values are expressed as mean ± SEM. Significance was determined by unpaired t-test.  *P < 0.05, **P < 0.01, ***P < 0.001.