B6.129P2-Pvalb^tm1(cre)Arbr/J

Stock number: 017320
Product name: B6 PV^cre
Research areas: Neurobiology Research, Research Tools

Description

PV-Cre knock-in (Pvalb-IRES-Cre) mice express Cre recombinase in parvalbumin-expressing neurons (such as interneurons in the brain and proprioceptive afferent sensory neurons in the dorsal root ganglia), without disrupting endogenous Pvalb expression. These mice may be useful in studying neuronal development, differentiation, and physiology.

Detailed description

The PV-Cre knock-in allele (Pvalb-IRES-Cre) has the endogenous parvalbumin promoter/enhancer elements directing Cre recombinase expression to Pvalb-expressing cells. Endogenous Pvalb expression remains intact. When crossed with a strain containing loxP site flanked sequence of interest, Cre-mediated recombination results in tissue-specific deletion of the target. Recombination occurs in more than 90% of neurons that express parvalbumin, such as interneurons in the brain and proprioceptive afferent sensory neurons in the dorsal root ganglia. This mutant mouse strain represents a model that may be useful in studies of neuronal differentiation.

Of note: parvalbumin is expressed in sperm; use of male PV-Cre mice may result in unwanted germline recombination and global recombination.
However, characterization of Pvalb-IRES-Cre performed by the Genetic Resource Science group at The Jackson Laboratory reports no Cre expression in spermatids [Mouse Genome Informatics (MGI) Allele Detail entry].
In addition, Luo et al. 2020 Neuron 106:37 compares this Pvalb-IRES-Cre knock-in to the Pvalb-T2A-Cre-D knock-in [Stock No. 012358 Pvalb^{tm1.1(cre)Aibs}]:
Pvalb-IRES-Cre did not exhibit germline recombination in multiple crosses from different labs, while Pvalb-T2A-Cre showed germline recombination through both parents. These findings are consistent with the stronger overall Cre activity in Pvalb-T2A-Cre mice than in Pvalb-IRES-Cre mice (Madisen et al. 2010 Nat Neurosci 13:133) and detection of Cre activity in spermatids of Pvalb-T2A-Cre but not Pvalb-IRES-Cre mice (Kobayashi and Hensch 2013 Front Neural Circuits 7:168).

If the recombinase activity pattern of this Pvalb-IRES-Cre allele is further characterized, such information may also be found searching the MGI Recombinase Activity and MGI Gene Expression + Recombinase Activity Comparison Matrix.

In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. This is the case for the strain above. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

Development

The Pv^cre knock-in allele (also called Pvalb-IRES-Cre) was created in the laboratory of Dr. Silvia Arber (Friedrich Miescher Institute) to have a an IRES enhancer and cre sequence inserted immediately downstream of the parvalbumin locus (Pvalb) on chromosome 15. The specific details are below.

An IRES-Cre-pA targeting cassette containing an internal ribosome entry site (IRES), a Cre recombinase coding sequence, a TK-Neo-Hygro sequence and polyadenylation site sequence was inserted into the 3' UTR of exon 5 of the Pvalb locus. The construct was electroporated into 129P2/OlaHsd-derived E14 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice. Heterozygotes were intercrossed to produce homozygotes. In 2008, homozygous PV-Cre mice on a B6;129P2 genetic background were sent to The Jackson Laboratory Repository as Stock No. 008069. Upon arrival, some mice were subsequently backcrossed to C57BL/6J inbred mice (Stock No. 000664) for at least five generations to generate this C57BL/6J-congenic colony (Stock No. 017320).

Allele

Symbol: Pvalb^tm1(cre)Arbr
Name: targeted mutation 1, Silvia Arber
MGI accession ID: MGI:3590684
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Pvalb
Marker name: parvalbumin
Chromosome: 15
Strain of origin: 129P2/OlaHsd
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: most neurons that express parvalbumin including interneurons in the brain and proprioceptive afferent sensory neurons in the dorsal root ganglia
Molecular note: An IRES-cre-pA cassette was inserted into the 3' UTR of exon 5.