B6N.Cg-Stra8^em2Dcp/J

Stock number: 034073
Product name: Stra8^delta121, Stra8^Δ121
Research areas: Reproductive Biology Research, Research Tools

Description

Expression of the long isoform of the mouse Stra8 (stimulated by retinoic acid gene 8) gene has been knocked out in these Stra8^delta121 CRISPR/Cas9-generated mice. Only the short isoform of the gene is expressed. This strain is useful in studies of meiosis and germ cell development.

Detailed description

Stra8 (stimulated by retinoic acid gene 8) is a germ cell-specific gene required for meiotic initiation. It additionally upreglates a transcriptional network of thousands of genes whose expression is not limited to meiosis. The mouse Stra8 gene encodes two isoforms, the longer of which is critical for meiotic initiation. The shorter isoform, lacking the first 111 amino acids, is not able to initiate meiosis.

These Stra8^Δ121 mice carry a CRISPR/Cas9-generated 121 bp deletion in exon 2 of the mouse Stra8 gene. The mutation knocks out expression of the long isoform of the gene, but the shorter isoform is still expressed. Homozygotes are viable, but not fertile; the testes and ovaries are reduced in size due to the inability of germ cells to initiate meiosis.

Development

The Stra8^Δ121 allele was developed using CRISPR/Cas9 methodologies. One-cell C57BL/6NTac-129S6/SvEvTac hybrid embryos were injected with a mixture of gRNA, Cas9, and a 200 bp single-stranded oligo encoding a FLAG peptide and an 8 amino acid linker (sequence GSGSGSGS), flanked on both sides by approximately 75 bp of exon 2 sequence.

Two mutant alleles were generated in this process: Stra8^FLAG, expressing a FLAG-tagged long-isoform protein (see Stock No. 034072) and this Stra8^Δ121 long-isoform knock-out allele (Stock No. 034073), carrying a 121 bp deletion in exon 2 instead of a FLAG insertion. The Stra8^Δ121 allele continues to express the short isoform of Stra8.

Stra8^Δ121 mutant mice were backcrossed to C57BL/6NTac for at least 10 generations by the donating laboratory. Upon arrival at The Jackson Laboratory, C57BL/6NJ (Stock No. 005304) was used for strain maintenance.

Allele

Symbol: Stra8^em2Dcp
Name: endonuclease-mediated mutation 2, David C Page
MGI accession ID: MGI:6303965
Generation method: Endonuclease-mediated
Attributes: Modified isoform(s)
Marker symbol: Stra8
Marker name: stimulated by retinoic acid gene 8
Chromosome: 6
Strain of origin: C57BL/6 x 129
Molecular note: Using an sgRNA and CRISPR/Cas9 technology, a repair of the double strand break with non-homologous end joining, resulting in a 121 bp deletion in Stra8 gene lacking the long isoform was generated.