C57BL/6J-Bdnf^em1Bxu/J

Stock number: 039260
Product name: Bdnf^NLuc
Research areas: Cell Biology Research, Neurobiology Research, Research Tools

Description

Bdnf^NLuc knock-in mice contain an insertion of a NanoLuciferase (NLuc) immediately before the stop codon of the Bdnf gene. These mice may be useful when studying the role of BDNF in neuronal development and survival, synaptic plasticity, and cognitive function.

Detailed description

Bdnf^NLuc knock-in (KI) mice contain a CRISPR/Cas9-mediated insertion of a NanoLuciferase (NLuc) sequence immediately before the stop codon of the brain derived neurotrophic factor (Bdnf) gene. NLuc is a luciferase enzyme smaller and more than a 100 times brighter than the regular firefly luciferase. BDNF is a neurotrophic factor that supports neuronal differentiation, maturation and survival as well as neurogenesis and synaptic plasticity, which is essential for learning and memory. Deficiencies in BDNF have been implicated in multiple neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease and multiple sclerosis. These KI mice express a BDNF-NLuc fusion protein.

Homozygous Bdnf^NLuc KI mice are viable and fertile; however, the donating laboratory does note that the homozygous mice demonstrate a mild obesity phenotype. NLuc activity was detected in cortical and striatal brain lysates, utilizing a Promega Nano-Glo Luciferase Assay System, as expected. These KI mice may be useful for evaluating BDNF function and localization in neurodegenerative diseases and may also be useful for screening therapeutics targeting BDNF.

In 2025, genotyping at The Jackson Laboratory identified the presence of an ampicillin resistance gene (AMP) that is segregating with the Bdnf^NLuc allele. It was not determined where within the Bdnf^NLuc allele the AMP resides.

Development

The Bdnf^NLuc knock-in reporter allele was generated using CRISPR/Cas9 endonuclease-genome editing. Guide RNAs [sgRNA1: 5'-GTGTATGTACACTGACCATT-3'; sgRNA2: 5'-GAATTGGCTGGCGATTCATA-3'] were selected to introduce a NanoLuciferase (NLuc) coding sequence immediately before the stop codon of the brain derived neurotrophic factor (Bdnf) locus on chromosome 2. Two silent mutations were also introduced into the PAM sites of the two sgRNAs located within the 5' homology arm in the donor plasmid. Ensembl Bdnf sequence (ENSUSG00000048482) was used as reference for generation of the sgRNAs and donor sequence. Cas9 nuclease mRNA, sgRNAs and a DNA donor template sequence were introduced into the cytoplasm of zygotes derived from C57BL/6J (Stock No. 000664) mice with well recognized pronuclei. Correctly targeted pups were identified by PCR and Sanger sequencing. The resulting founder mice were crossed to C57BL/6J mice for at least 4 generations to reduce off-target CRISPR changes. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Bdnf^em1Bxu
Name: endonuclease-mediated mutation 1,Baoji Xu
MGI accession ID: MGI:7612054
Generation method: Endonuclease-mediated
Attributes: Reporter
Synonyms: Bdnf ^NLuc
Marker symbol: Bdnf
Marker name: brain derived neurotrophic factor
Marker synonyms: ANON2; BULN2
Chromosome: 2
Strain of origin: C57BL/6J
Molecular note: Using the CRISPR/Cas9 technique, a NanoLuciferase (NLuc) coding sequence was inserted immediately before the stop codon of the brain derived neurotrophic factor (Bdnf) locus on chromosome 2.