Cdkl5 floxed mice contain loxP sites flanking exon 6 the X-linked cyclin-dependent kinase-like 5 (Cdkl5) gene, making them useful when studying neurodevelopmental disorders such as Rett syndrome, autism spectrum disorders, and early infantile epileptic encephalopathy.
Zhaolan (Joe) Zhou, University of Pennsylvania
Cyclin-dependent kinase-like 5 (Cdkl5) is an X-linked gene encoding a serine/threonine kinase that is highly expressed in the brain. Genetic mutations that disrupt CDKL5 function have been found in humans with neurodevelopmental disorders including atypical Rett syndrome (RTT), autism spectrum disorders (ASDs), and early infantile epileptic encephalopathy 2 (EIEE2). These individuals, classified under CDKL5 Disorder for the common genetic defect, are characterized by early-onset seizures, intellectual disability, and autistic features.
Cdkl5 floxed mice contain loxP sites flanking exon 6 of the X-linked cyclin-dependent kinase-like 5 (Cdkl5) gene. Cre Recombinase-dependent removal of murine exon 6, corresponding to exon 7 of human CDKL5, mimics a splice mutation found in humans that results in the skipping of exon 7, generating a premature stop codon and early truncation CDKL5 in its N-terminal kinase domain. For example, when bred to B6.FVB-Tg(EIIa-cre)C5379Lmgd/J mice (Stock No. 003724), male carriers, lacking CDKL5 expression, show autistic-like behavioral abnormalities, hyperactivity, motor impairments, decreased anxiety, deficits in social interaction, and impaired learning and memory with absence of spontaneous seizures. They also exhibit deficits in neural circuit communication.
Of note, the knock-out version of this allele is available as Stock No. 021967.
A targeting vector was designed to insert a loxP-flanked neomycin resistance (neo) cassette upstream of exon 6, and a single loxP site downstream of exon 6 of the X-linked cyclin-dependent kinase-like 5 (Cdkl5) gene. The construct was electroporated into 129Sv-derived embryonic stem (ES) cells. Correctly targeted ES cells were transfected with a Cre-expressing plasmid and ES cell clones with selective Neo removal, leaving floxed exon 6, were injected into C57BL/6 blastocysts. Resulting chimeric mice were bred to C57BL/6J mice for germline transmission and were subsequently backcrossed to C57BL/6J mice for 10 generations to establish a colony of Cdkl5 floxed mice. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation.
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. While the 43 markers throughout the genome suggested a C57BL/6 genetic background, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.
|Allele Name||targeted mutation 1.2, Zhaolan Zhou|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Cdkl5, cyclin-dependent kinase-like 5|
|Strain of Origin||129|
|Molecular Note||A floxed neo cassette was inserted upstream of exon 6. A loxP site was inserted downstream of exon 6. Cre-mediated recombination removed the neo cassette, but not exon 6.|
When maintaining a live colony, homozygous females may be bred to hemizygous males. Mutation is X-linked.
When using the Cdkl5 floxed mouse strain in a publication, please cite the originating article(s) and include JAX stock #030523 in your Materials and Methods section.