B6.Cg-Avpr1a^tm1Dgen Tg(AVPR1A)1Bux/BuxJ

Stock number: 025101
Research areas: Cell Biology Research, Developmental Biology Research, Neurobiology Research, Research Tools

Description

This humanized AVPR1A BAC transgenic mouse model has the human AVPR1A BAC transgene with the surrounding regulatory elements (hAVPR1A) and the mouse Avpr1a knockout allele (Avpr1a^-). These mice may be useful for studying the treatment of social cognitive impairments, psychiatric disorders, depression, violence and mood and anxiety disorders, as well as for exploring how variation in AVPR1A expression generates diversity in social behaviors.

Detailed description

This humanized AVPR1A BAC transgenic mouse model has the human AVPR1A BAC transgene with the surrounding genomic regulatory elements (hAVPR1A) and the mouse Avpr1a knockout allele (Avpr1a^-). The human AVPR1A protein is expressed at high levels in a profoundly divergent and more widely distributed pattern compared to the murine AVPR1A protein. While not perfectly consistent with human AVPR1A expression patterns, there are significant common features with rhesus macaque and human expression, including widespread cortical, hippocampal and thalamic expression. Human AVPR1A expression levels are not affected by the presence or absence of endogenous murine AVPR1A. Similarly, expression of endogenous oxytocin receptor (Oxtr), vasopressin (Avp) and oxtocin (Oxt) in hAVPR1A transgenic mice is similar to wildtype, regardless of the presence or absence of endogenous murine AVPR1A.

Mice hemizygous for the transgene and homozygous for the Avpr1a knockout (hAVPR1A,Avpr1a^-/- or h,-/-) are the fully humanized AVPR1A BAC transgenic mouse model. These mice display increased reciprocal social interactions compared to wildtype animals. Aspects of learning and memory (novel object recognition and spatial relocation recognition) are unaffected.

Mice noncarrier for the transgene and homozygous for the Avpr1a knockout (Avpr1a^-/-, 0,-/- or -/-) are described and available from The Jackson Laboratory as Stock No. 005776. Compared to age- and gender-matched wildtype animals, Avpr1a^-/- mice have significantly decreased prepulse inhibition (indicating a sensorimotor-gating/stimulus-processing deficit similar to that observed in some human schizophrenic patients), and display reduced anxiety, impaired reciprocal social interaction and decreased social recognition.

The prepulse inhibition impairments observed in Avpr1a^-/- animals are restored to normal levels in h,-/- mice; indicating that the human AVPR1A is functionally coupled to the appropriate effector systems and second messenger cascade in the mouse brain. In addition, h,-/- mice not only rescue deficits seen in knockout animals, but display a significant increase in reciprocal social interactions compared to wildtype levels. The social approach and preference for social novelty impairments (measured during 3-chamber task) were similar for Avpr1a^-/- and h,-/- animals.

Mice hemizygous for the transgene and wildtype at the Avpr1a locus (hAVPR1A,Avpr1a^+/+ or h,m/m) or mice hemizygous for the transgene and heterozygous for the Avpr1a knockout (hAVPR1A,Avpr1a^+/- or h,m/-) are viable and fertile. The donating investigator reports that h,m/m and h,m/- animals have not been extensively characterized for behavioral phenotype to date (May 2014). However, in biochemical analyses, the same ligand binding pattern is observed for h,m/m and h,m/- cohorts.

The donating investigator also reports that mice carrying the human transgene have a thinner coat covering evenly throughout their body compared to wildtype (noncarrier) mice from the colony.

Development

This humanized AVPR1A BAC transgenic mouse model has the human AVPR1A BAC transgene with the surrounding regulatory elements (hAVPR1A) and the mouse Avpr1a knockout allele (Avpr1a^-). When hemizygous for the transgene and homozygous for the knockout, these mice are called h,-/-. Specific details are below.

The Avpr1a^- knockout allele (Avpr1a^LacZ-neo or Avpr1a^tm1Dgen) was created by Deltagen to have a LacZ-Neo cassette ("IRES-lacZ-Neo555G") inserted into the arginine vasopressin receptor 1A locus (Avpr1a) on chromosome 10. Avpr1a^- mice backcrossed seven generations onto the C57BL/6 genetic background are described and available from The Jackson Laboratory as Stock No. 005776. Dr. Joseph D. Buxbaum (Icahn School of Medicine at Mount Sinai) obtained these animals and further backcrossed them onto C57BL/6 for three generations. The resulting Avpr1a^- mice (~N10 onto C57BL/6) were used as described below.

The human AVPR1A BAC transgene (hAVPR1A) was created by Dr. Joseph D. Buxbaum by first obtaining the 182 kbp bacterial artificial chromosome RP11-715H19 (GenBank# AC025525) that includes the entire human AVPR1A gene. The BAC also contains 109 kbp upstream of the AVPR1A transcription start site and 64 kbp downstream of the AVPR1A 3' untranslated region. The BAC transgene was injected into the pronuclei of B6C3 (C57BL/6xC3H mouse hybrid) fertilized eggs. Founder animals were bred to wildtype C57BL/6 mice to establish founder lines 1 and 13 (called line 1 and line 2, respectively, in the primary publication). The donating investigator reports that both founder lines had the same expression pattern, and animals from line 1 were chosen to characterize the behavior of transgenic animals. Founder line 1 mice were backcrossed to wildtype C57BL/6 mice for a total of at least eight generations. The resulting hAVPR1A line 1 mice (~N8 onto C57BL/6) were used as described below.

Next, Dr. Buxbaum bred Avpr1a^- mice (~N10 onto C57BL/6) with hAVPR1A line 1 mice (~N8 onto C57BL/6) to generate the humanized AVPR1A BAC transgenic mice. In 2014, frozen sperm from mice that were hemizygous for the transgene and heterozygous for the knockout (hAVPR1A,Avpr1a^+/- or h,m/+) was sent to The Jackson Laboratory as Stock No. 025101. To establish our living colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J inbred females (Stock No. 000664).

In 2015, a 32 SNP (single nucleotide polymorphism) panel analysis, with 27 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 first generation rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 4 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating in some mice (chromosomes 8 [~15.2 Mbp], 11 [~4.4 Mbp], 15 [~57.6 Mbp] and 19 [~49.9 Mbp]). These data suggest that the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J;C57BL/6N genetic background.

Allele

Symbol: Tg(AVPR1A)1Bux
Name: transgene insertion 1, Joseph Buxbaum
MGI accession ID: MGI:5538533
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(AVPR1A)1Bux
Marker name: transgene insertion 1, Joseph Buxbaum
Chromosome: UN
Strain of origin: C57BL/6 x C3H
Expressed genes: AVPR1A,arginine vasopressin receptor 1A,human
Site of expression: The human AVPR1A BAC transgene expression in mice has common features with rhesus macaque and human expression, including widespread cortical, hippocampal and thalamic expression.
Molecular note: The human AVPR1A BAC transgene (hAVPR1A) was created using a 182 kbp bacterial artificial chromosome RP11-715H19 (GenBank# AC025525) that includes the entire human AVPR1A gene. The BAC also contains 109 kbp upstream of the AVPR1A transcription start site and 64 kbp downstream of the AVPR1A 3' untranslated region. Founder lines 1 and 2 were established. The primary investigator reports that both founder lines have the same expression pattern, and animals from line 1 were chosen to characterize the behavior of transgenic animals.

Allele

Symbol: Avpr1a^tm1Dgen
Name: targeted mutation 1, Deltagen
MGI accession ID: MGI:3604506
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Avpr1a
Marker name: arginine vasopressin receptor 1A
Chromosome: 10
Strain of origin: 129P2/OlaHsd
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: lacZ expression is detected in testis, with strong expression detected in spermatogenic cells of the seminiferous tubules.
Molecular note: A bacterial lacZ gene was inserted into the gene such that the endogenous gene promoter drives expression of beta-galactosidase. RNA transcripts are detectable in: brain, subcortical region, brainstem, olfactory bulb, spinal cord, eye, Harderian glands, heart, lung, liver, pancreas, kidney, spleen, thymus, lymph nodes, bone marrow, skin, gallbladder, urinary bladder, adrenal gland, salivary gland, skeletal muscle, tongue, stomach, small intestine, large intestine, cecum, testis, epididymis, seminal vesicle, coagulating gland, prostate gland, ovaries, uterus and white fat. LacZ (beta-galactosidase) expression is detectable in testis.