Identification of Hypothalamic Arcuate Nucleus-Specific Enhancer Region of Kiss1 Gene in Mice

Pulsatile secretion of GnRH plays a pivotal role in follicular development via stimulating tonic gonadotropin secretion in mammals. Kisspeptin neurons, located in the arcuate nucleus (ARC), are considered to be an intrinsic source of the GnRH pulse generator. The present study aimed to determine ARC-specific enhancer(s) of the Kiss1 gene by an in vivo reporter assay. Three green fluorescent protein (GFP) reporter constructs (long, medium length, and short) were generated by insertion of GFP cDNA at the Kiss1 locus. Transgenic female mice bearing the long and medium-length constructs showed apparent GFP signals in kisspeptin-immunoreactive cells in both the ARC and anteroventral periventricular nucleus, in which another population of kisspeptin neurons are located. On the other hand, transgenic mice bearing 5′-truncated short construct showed few GFP signals in the ARC kisspeptin-immunoreactive cells, whereas they showed colocalization of GFP- and kisspeptin-immunoreactivities in the anteroventral perivent...