• The official symbol of Fxr in NCBI is Nr1h4. Farnesoid X receptor (FXR) is a transcription factor activated by ligands and classified within the nuclear receptor superfamily. It controls gene expression by attaching to DNA either as a single unit (monomer) or by forming a heterodimer with retinoid X receptor (RXR), a frequent partner for nuclear receptors, thereby binding to specific FXR response elements. There are two identified FXR gene variants: FXRα and FXRβ.
• Gene editing strategy: The exons 3~10 of the mouse Fxr gene were knocked out in B-Fxr KO mice. As a result, the mouse FXR protein will not be expressed anymore. The official symbol of Fxr in NCBI is Nr1h4.  
• Verification: Mouse Fxr mRNA was only detectable in wild-type C57BL/6JNifdc mice, but not in homozygous B-Fxr KO mice.
• Application: Mice homozygous for knock-out alleles exhibit increased bile salts and abnormal liver morphology and physiology. Mice homozygous for one knock-out allele also exhibit abnormal lipid homeostasis (MGI:1352464). This product can be used for the research of bile acid and lipid homeostasis

Gene targeting strategy for B-Fxr KO mice. The exons 3~10 of mouse Fxr gene were knocked out in B-Fxr KO mice. As a result, mouse FXR protein will not be expressed anymore.

Strain specific analysis of mFxr mRNA expression in wild-type C57BL/6JNifdc mice and homozygous B-Fxr KO mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-Fxr KO mice (-/-), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse Fxr primers. Mouse Fxr mRNA was only detectable in wild-type C57BL/6JNifdc mice but not in homozygous B-Fxr KO mice.

Biochemical test of B-Fxr KO mice. Values are expressed as mean ± SD.

Functional Analysis in B-Fxr KO mice. Serum was collected from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-Fxr KO mice (-/-) (n=5, 8-week-old), followed by Biochemistry Analysis. The NEFA, TC, TG, LDL-C, HDL-C, and TBA were increased in B-Fxr KO mice, which is consistent with the knockout phenotype in the findings reports. Significance was determined by t-test, *P<0.05, **P<0.01, ***P<0.001. Values are expressed as mean ± SEM.