B6(Cg)-Adnp^em1Pmtr/J

Stock number: 039849
Product name: Adnp^Flox
Research areas: Neurobiology Research, Research Tools

Description

Adnp^Flox mice carry a CRISPR/Cas9 generated mutation that results in loxP sites flanking exon 5 of the Adnp gene. These mice may be useful when studying the role of ADNP mutations on the onset of neurodevelopmental disorders.

Detailed description

Adnp^Flox mice have loxP sites flanking exon 5 of the activity-dependent neuroprotective protein (Adnp) gene. Adnp encodes a transcription factor that is important for mammalian brain formation. ADNP is a core subunit of the ChAHP chromatin remodeling complex, along with CHD4 and HP1 (Cbx3 or Cbx5) heterochromatic proteins, which is important in central nervous system development. Mutations in Adnp have been associated with the onset of neurodevelopmental disorders such as intellectual disability (ID) and autism spectrum disorder (ASD). Mutations are also associated with Helsmoortel-Van der Aa syndrome, characterized by global developmental delay, gastrointestinal problems, hypotonia, delayed speech, behavioral and sleep problems, pain insensitivity, seizures, structural brain anomalies, dysmorphic features, visual problems, early tooth eruption and autistic features.

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 5 deleted in the cre-expressing tissues. Exon 5 contains all but 67 of the 1108 total amino acids present in ADNP, including all of the putative DNA binding motifs.

Adnp^Flox mice were bred to Emx1-Cre mice (Stock No. 005628) to delete the floxed region specifically in the forebrain. Resulting conditional knockout (Adnp cKO) mice exhibit reductions in upper-layer cortical neurons, gross cortical and hippocampal hypoplasia, and behavioral defects in both males and females. Conditional heterozygotes (cHet) are normal.

The donating investigator reports breeding Adnp^Flox mice to Nestin-cre mice results in perinatal lethality after E15.5.

Development

Guide RNAs (GGGGGAACATTGGTCT and TCCAGGGACCAGAGGTG) were designed to insert loxP sites flanking exon 5 of the activity-dependent neuroprotective protein (Adnp) gene. Guide RNAs, Cas9 protein, and single-stranded donor DNA were introduced by microinjection into the cytoplasm of zygotes derived from C57BL/6N mice. Correctly targeted embryos were transferred to pseudopregnant females. Resulting Adnp^Flox mice were identified by long-range PCR and Southern blotting, and were further bred to C57BL/6J mice by the donating investigator (see SNP note below) for at least 8 generations to remove off-target CRISPR sites. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664). These mice were found to be carrying a neo cassette and an EYFP sequence from previous crosses with R26R-EYFP mice (Stock No. 006148). The R26R-EYFP allele was bred out of this colony upon arrival.

In 2024, 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 males sent to The Jackson Laboratory Repository. Two of the 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/6N;C57BL/6J genetic background.

Allele

Symbol: Adnp^em1Pmtr
Name: endonuclease-mediated mutation 1, Pierre Mattar
MGI accession ID: MGI:7738433
Generation method: Endonuclease-mediated
Attributes: Conditional ready (e.g. floxed)
Synonyms: Adnp^Flox
Marker symbol: Adnp
Marker name: activity-dependent neuroprotective protein
Marker synonyms: ADNP1; HVDAS; mKIAA0784; MRD28
Chromosome: 2
Strain of origin: C57BL/6N
Molecular note: CRISPR/Cas9 genome editing inserted loxP sites flanking exon 5 of the activity-dependent neuroprotective protein (Adnp) gene.