B6J.Cg-Vip^tm1(cre)Zjh/AreckJ

Stock number: 031628
Product name: Vip-IRES-cre (C57BL/6J) , B6J.Vip-IRES-cre
Research areas: Neurobiology Research, Research Tools

Description

Vip-IRES-Cre mice have Cre recombinase expression directed to Vip-expressing cells by the endogenous promoter/enhancer elements of the vasoactive intestinal polypeptide locus. Cre activity is detected in the neocortex, hippocampus, olfactory bulb, suprachiasmatic nuclei, and other discrete midbrain and brainstem regions. These mice may be useful to study neural GABAergic circuits throughout the mammalian brain.

While Vip-IRES-Cre was designed to retain endogenous Vip expression, a 2019 publication indicates this allele has reduced Vip expression - see details below. As such, researchers may use homozygous mice for routine colony maintenance, but should consider using heterozygous Vip-IRES-Cre mice and wildtype littermate controls in all their studies.

Stock No. 031628 is a C57BL/6J-congenic Vip-IRES-Cre knock-in mouse line, called Vip-IRES-Cre (C57BL/6J) or B6J.Vip-IRES-Cre. Of note, the same Vip-IRES-Cre knock-in allele is also available on a STOCK genetic background as Stock No. 010908 and a CBA/CaJ-congenic background as Stock No. 037964.

Detailed description

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. The phenotype summarized below is for the parental line: Vip-IRES-Cre knock-in mice on a C57BL/6;129S4 genetic background (Stock No. 010908). It should be noted that the phenotype of this C57BL/6J-congenic Vip-IRES-Cre knock-in line (Stock No. 031628 ; Vip-IRES-Cre (C57BL/6J) or B6J.Vip-IRES-Cre) could vary from that of the parental line from which it was derived. The phenotype below describes the parental line (Stock No. 010908).

The Vip-IRES-Cre allele harbors an internal ribosome entry site and Cre recombinase in the 3' UTR of the vasoactive intestinal polypeptide locus (Vip). As such, it is designed to have the endogenous Vip promoter/enhancer elements directing cre expression in the neocortex, hippocampus, olfactory bulb, suprachiasmatic nuclei and other discrete midbrain and brainstem regions. When Vip-IRES-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the Vip-expressing cells in the offspring. While Vip-IRES-cre was designed to retain endogenous Vip expression, a 2019 publication indicates this allele has reduced Vip expression - see details below. As such, researchers may use homozygous mice for breeding, but should consider using heterozygous Vip-IRES-Cre mice and wildtype littermate controls in all their studies.

In 2010, the donating investigator for Stock No. 010908 reported Cre recombinase activity is specific and efficient (largely recapitulates the endogenous Vip expression pattern with highly efficient recombination). They report Cre recombinase activity in some GABAergic interneurons, and did not examine cre expression in the intestine or tissues other than brain. VIP expression from this Vip-IRES-Cre allele was not evaluated by the donating investigator (January 2010) - see additional details below. They also reported that homozygous mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities.

Additional characterization information may be found on the Allen Institute for Brain Science website (Vip-IRES-Cre images).

If the recombinase activity pattern of this allele is further characterized by the Genetic Resource Science group at The Jackson Laboratory, such findings will be reported on the Mouse Genome Informatics (MGI) Allele Detail entry (Vip^tm1(cre)Zjh). This same information would also be found searching the MGI Recombinase Activity database.

While this Vip-IRES-cre allele was designed as a 3' knock-in allele, Cheng et al. 2019 J Biol Rhythms (PMID:31452438) indicates the Vip-IRES-cre allele has reduced Vip expression. When examined at 2 days of age, Vip-IRES-cre heterozygotes exhibit reduced expression of the neuropeptide products encoded by the Vip gene (VIP and peptide histidine isoleucine [PHI]) in the suprachiasmatic nucleus (SCN) of the hypothalamic nucleus, when compared to wildtype littermates. The total number of VIP/PHI-positive neurons within the SCN was not different between Vip-IRES-cre heterozygotes and wildtype littermates - ruling out a potential loss of VIP/PHI neurons. Expression of other neuropeptides was not altered. The wheel-running activity rhythms of heterozygous mice were not affected.

Development

The Vip-IRES-Cre knock-in allele was designed by Dr. Z. Josh Huang (Cold Spring Harbor Laboratory). A targeting vector was designed to insert an internal ribosome entry site (IRES), a Cre recombinase sequence, an SV40 polyA signal and a frt-flanked neo cassette into the 3' untranslated region (after the translational termination site) of the vasoactive intestinal polypeptide locus (Vip) on chromosome 10. This construct was electroporated into (C57BL/6 x 129S4Sv/Jae)-derived V6.5 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient tetraploid blastocysts. Chimeric animals were bred with Actin-FLPe mice (on a C57BL/6-congenic background [N10]; see Stock No. 005703) to generate the colony and remove the neo selection cassette. The resulting Vip-IRES-Cre mice were subsequently bred together for several generations (and the FLPe transgene was removed). In 2010, Vip-IRES-Cre knock-in mice on a mixed genetic background (C57BL/6;129S4 ; animals showing either agouti or black coat color) were sent to The Jackson Laboratory Repository. Upon arrival, sperm was cryopreserved. An aliquot of that frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664) and rederive our live colony as Stock No. 010908 - which was thereafter maintained by breeding mutant mice together.

In July 2016, Drs. Andrew K. Recknagel and Melissa R. Warden (Cornell University) purchased some Stock No. 010908 animals (total backcross generation N1 onto C57BL/6J). They further backcrossed them to C57BL/6J inbred mice for at least five additional generations - establishing their C57BL/6J-congenic Vip-IRES-Cre knock-in mouse line, called Vip-IRES-Cre (C57BL/6J) or B6J.Vip-IRES-Cre. In 2018, they sent B6J.Vip-IRES-Cre males with black coat color to The Jackson Laboratory Repository as Stock No. 031628. Upon arrival, males were used to cryopreserve sperm. To establish the living mouse colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J inbred mice (Stock No. 000664).

Of note, Dr. Recknagel reports that, at least once during backcrossing, a heterozygous female was bred to a C57BL/6J inbred male (thus the Y chromosome of this congenic strain is of C57BL/6J origin).

A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. One of the 43 markers, on Chromosome 8, was segregating with 129.

Allele

Symbol: Vip^tm1(cre)Zjh
Name: targeted mutation 1, Z Josh Huang
MGI accession ID: MGI:4431361
Generation method: Targeted
Attributes: Recombinase-expressing
Synonyms: VIP-Cre; Vip-IRES-cre
Marker symbol: Vip
Marker name: vasoactive intestinal polypeptide
Marker synonyms: PHI, peptide histidine isoleucine; PHM27; vip/phi27
Chromosome: 10
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombinase activity is observed in some GABAergic interneurons.
Molecular note: A targeting vector was designed to insert an internal ribosome entry site (IRES), a cre recombinase sequence, an SV40 polyA signal, and an frt-flanked neo cassette into the 3' untranslated region (after the translational termination site) of the vasoactive intestinal polypeptide locus (Vip). This construct was electroporated into C57BL/6 x 129S4/SvJae hybrid embryonic stem (ES) cells. Chimeric mice were bred with Actin-FLPe mice (on a C57BL/6 congenic background) to generate the colony and remove the neo selection cassette. The FLPe transgene has been bred out of the line.