BALB/cJ-Cst6^ichq/J

Stock number: 002167
Product name: harlequin ichthyosis
Research areas: Dermatology Research

Detailed description

Homozygous Cst6^ichq mice develop thick skin due to formation of compact, orthokeratotic scales that fracture over articular surfaces, secondary to bending. Harlequin ichthyosis mice on the inbred BALB/cJ background die between 9 and 12 days of age. The harlequin ichthyosis mouse mutation is very similar to human type 2 harlequin ichthyosis for which it may be a good model.

Development

The thss mutation arose spontaneously in 1999 on the coisogenic strain BALB/cJ-Cst6^ichq/J at The Jackson Laboratory. This mutant subline was maintained by sibling inbreeding for 29 generations and the ichthiosis phenotype was not seen. In 2011 sperm was cryopreserved from homozygous males at generation F29.

Allele

Symbol: Cst6^ichq
Name: harlequin ichthyosis
MGI accession ID: MGI:2447068
Generation method: Spontaneous
Attributes: Null/Knockout
Synonyms: ichq
Marker symbol: Cst6
Marker name: cystatin E/M
Marker synonyms: ECTD15
Chromosome: 19
Strain of origin: BALB/cJ
Molecular note: The ichq mutation arose spontaneously in a colony of BALB/c mice at The Jackson Laboratory in 1989. The molecular basis for this mutation is a single nucleotide deletion of a G residue at sequence position 42 in exon 1 of the Cst6 gene. This results in a shift of the reading frame, resulting in a premature stop codon at amino acid position 20 of the encoded protein. In addition to the single nucleotide deletion, the mutant allele also carried two C-to-T SNPs in exon 1 at positions 33 and 40. Immunohistochemical analysis confirmed the predicted absence of cystatin M/E at the protein level in homozygous mice.