STOCK Kiss1^{tm1.1(cre/EGFP)Stei}/J

Stock number: 017701
Product name: Kiss1-CreGFP, Kiss1^Cre:GFP v1

Research areas: Neurobiology Research, Reproductive Biology Research, Research Tools

Description

The Kiss1-CreGFP allele expresses a CreGFP fusion protein from the Kiss1 promoter/enhancer elements. These knock-in mice may be useful for visualizing KISS1 secreting neurons and for studying their role in fertility.

Detailed description

The Kiss1-CreGFP allele expresses a CreGFP fusion protein (EGFP and cre fusion protein) from the Kiss1 promoter/enhancer elements. KISS1 (Kisspeptin) mediates the onset of puberty by regulating the feedback effects of gonadotropin-releasing hormone (GnRH) and luteinizing hormone secretion from GnRH neurons. Heterozygous mice are viable and fertile, normal in size and do not display any gross physical or behavioral abnormalities. The DI states that homozygous mice are often infertile. When Kiss1 is induced, EGFP immunofluorescence is observed in the hypothalamic arcuate nucleus (ARC) of both sexes and anteroventral periventricular nucleus (AVPV) in females. When Kiss1-CreGFP mice are bred with mice containing loxP-flanked sequence, cre-mediated recombination will result in deletion of the floxed sequences in the Kiss-expressing neurons of the offspring. These mice may be useful for visualizing KISS1 secreting neurons and for studying their role in fertility.

Update January, 2019:
Kiss1^Cre:GFP (v2) (see Stock No. 033169) represents an improved version of this Kiss1^{tm1.1(cre/EGFP)Stei} allele (Stock No. 017701, also called Kiss1^Cre:GFP v1), which is prone to ectopic expression when crossed to conditional reporter mice, as well as retains levels of low expression. Unlike the Kiss1^{tm1.1(cre/EGFP)Stei} (v1), homozygotes of the Kiss1^Cre:GFP (v2) line are Kiss1 null and infertile. Homozygous Kiss1^Cre:GFP (v2) males have diminished testosterone levels compared to heterozygotes.
Barring genetic crosses, the Kiss1^Cre:GFP v1 line (Stock No. 017701) remains a useful tool for visualizing Kiss1 neurons for electrophysiological recordings with the GFP-fused cre-reporter transgene. No immunohistochemistry is required to visualize GFP expression in the Kiss1^Cre:GFP v1 line line. Also, viral injections into adult v1 mice, as opposed genetic crosses, can be used to gain control of those Kiss1 neurons and thereby avoid developmental ectopic recombination.

Development

A targeting vector was designed to insert a CreGFP fusion protein cassette and frt-flanked neomycin (neo) selection cassette upstream of the 5' translation start of the KiSS-1 metastasis-suppressor (Kiss1) targeted gene. Specifically, this targeting vector contained an enhanced green fluorescent protein (EGFP) and a Cre recombinase. This construct was electroporated into F1 hybrid (129S6/SvEvTac x C57BL/6NCr)-derived G4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and chimeric males were bred with C57BL/6 females. These Kiss1-CreGFP mice were bred with FLPe mice (on a C57BL/6 congenic background) to remove the neo selection cassette. Resulting offspring were bred to C57BL/6J mice for at least 3 generations and were maintained on this mixed genetic background. Upon arrival at The Jackson Laboratory, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Kiss1^{tm1.1(cre/EGFP)Stei}
Name: targeted mutation 1.1, Robert A Steiner
MGI accession ID: MGI:5298495
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter; Null/Knockout
Marker symbol: Kiss1
Marker name: KiSS-1 metastasis-suppressor
Chromosome: 1
Strain of origin: (129S6/SvEvTac x C57BL/6NCrl)F1
Expressed genes: GFP,Green Fluorescent Protein,; cre,cre recombinase,bacteriophage P1
Site of expression: EGFP immunofluorescence is observed in the hypothalamic arcuate nucleus (ARC) of both sexes and anteroventral periventricular nucleus (AVPV) in females.
Molecular note: A targeting vector was designed to insert a CreGFP fusion protein cassette and frt-flanked neomycin (neo) selection cassette upstream of the 5' translation start of the KiSS-1 metastasis-suppressor (Kiss1) targeted gene. Specifically, this targeting vector contained an enhanced green fluorescent protein (EGFP) and a Cre recombinase. This construct was electroporated into F1 hybrid (129S6/SvEvTac x C57BL/6NCr)-derived G4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and chimeric males were bred with C57BL/6 females. These Kiss1-CreGFP mice were bred with FLPe mice (on a C57BL/6 congenic background) to remove the neo selection cassette. When Kiss1 is induced, EGFP immunofluorescence is observed in the hypothalamic arcuate nucleus (ARC) of both sexes and anteroventral periventricular nucleus (AVPV) in females. Homozygotes are often infertile, but heterozygotes display normal fertility.