Slo3-EGFP+ floxed mice possess loxP sites flanking exon 27 of the Kcnu1 gene and a green fluorescent protein sequence. This strain may be useful for studying spermatozoan pH-dependent potassium ion currents and their effect on fertility and fertilization.
Christopher J. Lingle, Washington University School of Medicine
Slo3-EGFP+ floxed mice possess loxP sites flanking exon 27 of the Kcnu1 potassium channel, subfamily U, member 1 (Kcnu1) gene and a green fluorescent protein sequence. SLO3 is a spermatozoa specific potassium channel activated by both intracellular pH and membrane voltage that mediates export of K(+). Regulation of osmotic pressure and alkalization of sperm is critical for fertility. Slo3-EGFP+ mice that are homozygous for this allele are viable and fertile. Fluorescence is evident in the testis and total K+ current in the sperm is somewhat reduced in these mice compared to wildtype. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 27 deleted in cre-expressing tissues.
A targeting vector was designed by Dr. Xiao-Ming Xia (laboratory of Dr. Christopher Lingle, Washington University School of Medicine) to insert a loxP site upstream of exon 27 of the potassium channel, subfamily U, member 1 (Kcnu1) gene. The construct also inserted an enhanced green fluorescent protein and a second loxP site, followed by a frt-flanked neomycin resistance (neo) cassette which included a third loxP site, downstream of exon 27. The construct was electroporated into C57BL/6-derived BLU embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and resulting chimeric mice were bred with B6;SJL-Tg(ACTFLPe)9205Dym/J transgenic mice (Stock No. 003800) to delete the neo cassette. Resulting progeny were crossed to remove the Flp-expressing transgene, and Slo3-EGFP+ offspring were backcrossed to C57BL/6J mice for at least 15 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).
|Allele Name||targeted mutation 1.1, Christopher J Lingle|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Kcnu1, potassium channel, subfamily U, member 1|
|Strain of Origin||C57BL/6NTac-Tg(HBB-lacZ)ALey/Ley|
|General Note||The primary investigator indicates that the ES cell line used was C57BL/6-derived BLU.|
|Molecular Note||A loxP site was inserted upstream of exon 27. A cassette (5' to 3': EGFP, loxP, FRT, neo resistance marker, loxP, and FRT) was inserted downstream of exon 27. Flp-mediated recombination removed the neo cassette. Exon 27 and the EGFP remain floxed.|
When maintaining a live colony, homozygous mice may be bred together.
When using the Slo3-EGFP+ mouse strain in a publication, please cite the originating article(s) and include JAX stock #028415 in your Materials and Methods section.