Mice that are homozygous for this targeted mutation of Per2, period homolog 2 (Drosophila), exhibit a short circadian period initially when housed in constant darkness, and then exhibit gradual loss of rhythmicity. Homozygotes exhibit phase shift responses to light. This mutant mouse strain may be useful in studies of circadian rhythm and sleep patterns.
David R. Weaver, Univ of Massachusetts Medical School
Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Abberant gene products (mRNA) are detected by RT-PCR and RACE analysis of brain total RNA. No gene product (protein) is detected in homozygous mutant mice by immunohistochemical staining of superchiasmatic nuclei sampled over a 24 hour period. Western blots of liver reveal a deletion mutant protein product is produced. When housed in constant darkness, homozygotes have a short circadian period initially, and then exhibit gradual loss of rhythmicity. Homozygotes exhibit phase shift responses to light. This mutant mouse strain may be useful in studies of circadian rhythm and sleep patterns.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. This is the case for the strain above. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
A targeting vector containing a PGKneo cassette was used to disrupt exon 5 and a portion of exon 6. The construct was electroporated into 129S4/SvJae derived J1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The resulting chimeric male animals were crossed to 129/sv female mice, and then backcrossed to C57BL/6J for 10 generations.
|Allele Name||targeted mutation 1, David R Weaver|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||mPer2ldc; Per2-; Per2m|
|Gene Symbol and Name||Per2, period circadian clock 2|
|Strain of Origin||129S4/SvJae|
|Molecular Note||Exon 5 and a portion of exon 6 were replaced with a neomycin selection cassette. Several transcript forms produced from the targeted allele were identified in homozygous mutant mice via RT-PCR and RACE analyses of brain RNA. The different transcripts involved aberrant splicing of exon 4 to a pseudoexon in intron 4, to a cryptic splice site within neo, and to exon 7. In spite of the transcripts having in-frame regions, normal protein was undetected in by immunohistochemical staining of superchiasmatic nuclei over a 24 hour period.|
|Mutations Made By|| |
Shin Yamazaki, Vanderbilt University
When maintaining a live colony, these mice can be bred as homozygotes.
When using the mPer2ldc , Per2m mouse strain in a publication, please cite the originating article(s) and include JAX stock #010492 in your Materials and Methods section.