Agonist-stimulated endocytosis of synaptic AMPA glutamate receptors is impaired in mice homozygous for the Caly knockout allele. These mice may be useful in studies of clathrin-mediated endocytosis in the central nervous system, neuronal synaptic vesicle trafficking and recycling, as well as neuregulin processing and AP-3 dependent axonal transport.
Clare Bergson, Georgia Health Sciences University
Calcyon neuron-specific vesicular protein regulates clathrin-mediated endocytosis and AP-3 dependent endosomal trafficking. These knock-out mice carry a targeted mutation of the Caly gene in which exons 3 through 6 have been excised. Agonist-stimulated endocytosis of synaptic AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) glutamate receptors (AMPARs), proteolytic processing of neuregulin 1, and axonal targeting of AP-3 cargos are impaired in the brains of homozygotes. Cultured hippocampal neurons isolated from homozygotes and CA1 region brain slices lack long-term synaptic depression (LTD). Mice that are homozygous for the targeted mutation are viable and fertile. No gene product (mRNA) is detected by RT-PCR analysis of brain tissue from homozygotes.
During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.
A targeting vector was used to insert an FRT site-flanked NEO cassette into intron 6 and loxP sites upstream of exon 3 and downstream of exon 6. The construct was electroporated into unspecified C57BL/6-derived embryonic stem (ES) cells. Correctly targeted ES cells, containing the Calfl allele, were injected into BALB/c blastocysts. The resulting male chimeric animals were crossed to C57BL/6 female mice. Heterozygous Calcyonfl mice were crossed to generate homozygotes. Homozygotes were crossed to CMVCRE mice to excise exons 3 through 6 and the FRT-flanked NEO cassette. The mice were then backcrossed to C57BL/6 for at least 10 generations. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.
Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 1.1, Clare Bergson|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Caly, calcyon neuron-specific vesicular protein|
|Strain of Origin||C57BL/6|
|Molecular Note||Mice homozygous for the floxed Calytm1Cber allele were crossed with Tg(CMV-cre)1Cgn transgenic mice to generate null homozygotes that were then used for further breeding. No mRNA was detectable by RT-PCR on cortex and hind-brain extracts from homozygotes.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the CalyKO mouse strain in a publication, please cite the originating article(s) and include JAX stock #023129 in your Materials and Methods section.