Chd1flox/flox mice possess loxP sites flanking exon 2 of the chromodomain helicase DNA binding protein 1 gene making this strain useful for studying chromatin remodeling during embryonic stem cell differentiation.
Alexandra Lusser, Medical University of Innsbruck
Chd1flox/flox mice possess loxP sites flanking exon 2 of the chromodomain helicase DNA binding protein 1 (Chd1) gene. Exon 2 contains the start codon for the Chd1 gene. CHD1 is an ATP-dependent chromatin remodeling factor involved in transcription regulation and chromatin assembly. CHD1 is frequently mutated in human prostate cancer. Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues. This deletion results in the production of an N-terminally truncated protein. Embryonic stem cells derived from resulting Chd1Δ2/Δ2 mice exhibit differentiation defects.
A targeting vector was designed by Dr. Paolo Piatti (Medical University of Innsbruck) to insert a loxP upstream of exon 2 (containing the start codon), and a frt-flanked neomycin resistance (neo) cassette, followed by a second loxP site, downstream of exon 2 of the chromodomain helicase DNA binding protein 1 (Chd1) gene. The construct was electroporated into B6(Cg)-derived Bruce4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into CD-1 blastocysts and resulting chimeric males were bred with B6(Cg)-Tyrc-2J/J females (Stock No. 000058). The donating investigator reported that the resulting Chd1flox/flox offspring were bred to C57BL/6NCrl mice for at least 3 generations. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 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. One of the 27 markers throughout the genome was segregating. Also, 4 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, Alexandra Lusser|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Chd1, chromodomain helicase DNA binding protein 1|
|Strain of Origin||B6.Cg-Thy1a|
|Molecular Note||A targeting vector was designed to insert a loxP upstream of exon 2 (containing the start codon), and an FRT-flanked neomycin resistance (neo) cassette, followed by a second loxP site, downstream of exon 2.|
When maintaining a live colony, homozygous mice may be bred together.
When using the Chd1flox mouse strain in a publication, please cite the originating article(s) and include JAX stock #029262 in your Materials and Methods section.