B6;C3-Oxtr^em1Yinn/J

Stock number: 037580
Product name: Oxtr^1xPA-tdTom
Research areas: Neurobiology Research, Research Tools

Description

Oxtr^1xPA-tdTom knock-in mice express a PA-tag and tdTomato under direction of the endogenous oxytocin receptor (Oxtr) promoter in brain regions. This mouse strain could be useful for oxytocin receptor visualization and manipulation.

Detailed description

Oxtr^1xPA-tdTom knock-in mice express a tdTomato fluorescent reporter under direction of the endogenous oxytocin receptor (Oxtr) promoter. Inserted just upstream of the Oxtr stop codon, this insertion did not disrupt its endogenous transcriptional regulations. This line harbors a PA-tag at the C-terminus of the receptor protein. Oxtr encodes a G-protein coupled receptor for the neuropeptide oxytocin (Oxt), which is produced in the hypothalamus. Oxt plays important roles in modulating social behaviors such as social recognition, social learning, pair bonding, anxiety, autism, and maternal behaviors.

Using anti-tdTomato and anti-PA-tag antibodies in the 2 week old brains from Oxtr^1xPA-tdTom males, analysis shows abundant expression of both in the cortical region, hippocampal dentate gyrus (DG) and anterior CA2 (aCA2)/CA3, paraventricular thalamus (PVT), central nucleus of amygdala (CeA), dorsal endopiriform nucleus (DEn), and posteromedial cortical amygdaloid area (PMCo), where endogenous OXTR expression has previously been reported. tdTomato expression is also detectable using direct fluorescence in younger animals.

Homozygous mice are viable and fertile.

Of note, an icre expressing line (Stock No. 037578) and an iCre/ERT2 expressing line (Stock No. 037579) are both available.

Development

crRNA/tracrRNA duplex gRNA (incorporating crRNA CCAUCCUCGGCAUGAGCCAUguuuuagagcuaugcuguuuug) was designed to insert a PA-tag (human podoplanin-derived epitope tag), a viral 2A oligopeptide (T2A; mediates ribosomal skipping), and a constitutively fluorescent orange fluorescent protein (tdTomato) sequence immediately before the stop codon of the oxytocin receptor (Oxtr) gene. The crRNA/tracrRNA, targeting vector, and the Cas9 nuclease protein were introduced into the pronuclei of fertilized eggs from hybrid B6C3F1 mice. Targeted embryos were transferred to pseudopregnant females. Correctly targeted pups were identified by PCR and Sanger sequencing which also confirmed the absence of random insertions. Resulting Oxtr^1xPA-tdTom mice were further backcrossed to C57BL/6J mice (Stock No. 000664) for two generations by the donating laboratory. Cryopreserved sperm was sent to The Jackson Laboratory. Upon arrival, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes to establish our live colony.

Allele

Symbol: Oxtr^em1Yinn
Name: endonuclease-mediated mutation 1, Yukiko U Inoue
MGI accession ID: MGI:7333088
Generation method: Endonuclease-mediated
Attributes: Reporter; Epitope tag
Marker symbol: Oxtr
Marker name: oxytocin receptor
Chromosome: 6
Strain of origin: (C57BL/6 x C3H)F1
Molecular note: Using CRISPR/cas9 technology, a 1xPA-tag and a T2A-tdTomato expression cassette were inserted into the Oxtr gene just upstream of the stop codon.