Mice heterozygous for this Oct4-neo mutation are viable and fertile, harboring an IRES-GFPneo fusion cassette downstream of exon 5 of the Oct4 (Pou5f1) gene. The donating investigator reports (and attempts at The Jackson Laboratory confirm) no living homozygous animals are born. While sufficient neomycin-resistance activity is observed in embryonic stem cells, no visible GFP fluorescence is reported. When treated with specific transcription factors (Oct4, Sox2, c-Myc and Klf4), some Oct4-neo murine embryonic fibroblasts (MEFs) have the properties of induced pluripotent stem (iPS) cells. Such iPS cells have the DNA methylation, gene expression and chromatin state of embryonic stem cells and can form viable chimeras, contribute to the germ line, and generate live late-term embryos when injected into tetraploid blastocysts. These Oct4-neo mutant mice may be useful for the selection of iPS cells (i.e. epigenetic reprogramming of somatic cells into pluripotent embryonic stem cells).
Of note, these Oct4-neo mutant mice may also be used in conjunction with Oct4-EGFP mice (Stock No. 008214); a similar mutant strain bearing an EGFP-expressing mutation from the Oct4 locus.
