Myenteric neurons from these P2rx2 knock-out mice exhibit altered intracellular electrophysiological action potentials. Peristalsis in mutant mice is impaired in the ileum, and ventilatory response to hypoxia is diminished.
Debra A Cockayne, Roche Bioscience
Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. No gene product (mRNA or protein) is detected by RT-PCR of intestinal tissue or Western blot analysis of dorsal root and trigeminal ganglia. No immunoreactive staining was detected in ileum by immunohistochemical analysis. Myenteric neurons exhibit altered intracellular electrophysiological action potentials. Fast excitatory postsynaptic potentials (fEPSPs) from mutant S neurons (myenteric plexus interneurons and motorneurons) are inhibited by the nicotinic cholinergic receptor antagonist, mecamylamine. ATP-induced depolarization of isolated mutant S neurons is abolished. Peristalsis is impaired in the ileum. Mutant mice ventilatory response to hypoxia is diminished, as determined by in vitro carotid sinus nerve preparation. ATP and ATP analog (alpha,beta-methyleneATP) elicits a faster discharge (afferent activity) in mutant sinus nerves. This mutant mouse strain may be useful in studies related to pain and peripheral nerve hypersensitivity, and sensory perception.
A targeting vector containing neomycin resistance and herpes simplex virus thymidine kinase genes was used to disrupt exons 2 through 11. The construct was electroporated into 129P2/OlaHsd-derived E14.1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts.
|Allele Name||targeted mutation 1, Debra A Cockayne|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||P2rx2, purinergic receptor P2X, ligand-gated ion channel, 2|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||Exons 2 through 11 were deleted and replaced by a neomycin resistance cassette by homologous recombination in ES cells. RT-PCR analysis confirmed absence of mRNA in whole brain and testis from homozygous mutant mice, whereas the expected band was obtained in wild-type mice.|
The resulting chimeric animals were crossed to C57BL/6J mice, and then backcrossed to C57BL/6J for 6 generations (using a speed congenic protocol) before being made homozygous. When maintaining a live colony, these mice are bred as homozygotes.
When using the P2X2 KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #004603 in your Materials and Methods section.