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.