Histamine receptor H1 (H1R) KO mice may be useful when studying the role of histamine during allergic reaction and the regulation of neurotransmission.
Benjamin Renquist, University of Arizona
H1R KO mice have a neo cassette, in reverse orientation to the gene, replacing the initiation codon of the histamine receptor H1 (Hrh1) gene, abolishing gene expression. Homozygotes are viable and fertile. H1R is a G protein-coupled receptor that mediates the contraction of smooth muscles and neurotransmission in the central nervous system. It is involved in multiple processes including memory and learning, circadian rhythm, and thermoregulation. It is also known to contribute to inflammatory responses and allergic reactions. H1R KO mice have increased amounts of brown and white adipose tissue, with increased body weight after 28 weeks of age. At 48 weeks of age mice have decreased circulating insulin levels, with increased leptin, free fatty acid, and triglyceride levels. These mice also display decreased T and B cell proliferation, and decreased levels of some immunoglobulins such as IgM and IgG3 following stimulation with ovalbumin.
A targeting vector was designed to replace the initiation codon of the histamine receptor H1 (Hrh1) gene with a neomycin resistance (neo) cassette in reverse orientation to the gene. The construct was electroporated into 129P2/OlaHsd-derived E14 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and the resulting chimeric males were bred to C57BL/6 females. Offspring were bred to C57BL/6J mice for at least 20 generations. 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 Name||targeted mutation 1, Takeshi Watanabe|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||H1KO; H1R-; H1RKO; Hrh1-; Hrh1tm1Wat|
|Gene Symbol and Name||Hrh1, histamine receptor H1|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||A 0.8 kb fragment containing the initiation codon was replaced with a neomycin selection cassette inserted in reverse transcriptional orientation relative to the gene. Receptor binding studies on brain sections of homozygous mice confirmed that no functional protein was made from this allele.|
When maintaining a live colony, homozygous mice may be bred together.
When using the H1R KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #029346 in your Materials and Methods section.