Reproduction Abstracts

Kisspeptin-GPR54 signaling plays a key role to govern reproductive function through regulating GnRH/gonadotropin release in mammals, including rodents, ruminants, reflex ovulators, and primates. Surge and pulse modes of GnRH/gonadotropin secretion are responsible for ovulation and gametogenesis/steroidogenesis, respectively. It has been suggested that kisspeptin neurons located in the anterior hypothalamus, such as the anteroventral periventricular nucleus (AVPV) and preoptic ...

Neurons essential for reproductive functions are distributed in hypothalamus. The precise functions of these neurons are not fully analyzed at a cellular level, especially in domestic animals. To analyze cellular mechanisms that control ruminant reproduction, we generated neuronal cell lines by immortalizing fetal goat hypothalamus.The hypothalamic arcuate nucleus was collected from a female Shiba goat at E118. The tissue was dispersed and plated. Twenty...

Brain mechanism responsible for LH surge generation shows sexual dimorphism in rodents. The dimorphism is considered to be due to the perinatal estrogen converted from testicular androgen during developing period. The present paper aimed to clarify the mechanisms mediating the estrogen-induced defeminization of LH surge-generating system. The microarray analysis is an attempt to obtain the candidate gene(s) mediating the perinatal estrogen action causing the brain sexual diffe...

Introduction: Kisspeptin, encoded by Kiss1, is a neuropeptide that directly regulates GnRH secretion from the hypothalamus. The present study aimed to examine a relationship between the circulating gonadotropin levels and follicle development using the Kiss1 knockout (Kiss1 KO) adult female rats.Materials and methods: Kiss1 KO and WT animals were obtained by mating of Kiss1+/− males and female...

Kisspeptin, encoded by Kiss1 gene, is considered to be a key regulator for GnRH secretion. Kiss1 knockout (KO) rats are infertile due to the absence of gonadotropin secretion in both sexes. Kiss1 KO male rats receiving testosterone during their adult age showed no male sexual behaviors (mount, intromission, and ejaculation), but showed female sexual behavior (lordosis) in Kiss1 KO males. To examine whether kisspeptin is also needed to induce...

Pulsatile secretion of GnRH/LH is indispensable for puberty onset and normal reproductive functions in mammalian species. A cohort of neurons expressing three neuropeptides, kisspeptin, neurokinin B (NKB), and dynorphin (KNDy neurons), localized in the hypothalamic arcuate nucleus (ARC), are considered to be a source of GnRH pulse generator. A synchronous discharge of KNDy neurons might be obligatory for pulsatile GnRH secretion. The present study aimed to determine whether NK...

Two populations of kisspeptin neurons, located in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV), are considered to be involved in generating GnRH pulse and surge respectively. The present study aimed to determine the region-specific enhancer for ARC Kiss1 gene expression by in vivo reporter assay using transgenic (Tg) mice. Three GFP reporter constructs (long-, middle-, and short-length) were generated by insertion of GFP cDNA in ...

Kisspeptin, encoded by Kiss1 gene, has attracted attention as a key neuropeptide in controlling reproduction in mammals. Earlier studies with Kiss1 or its cognate receptor Gpr54 knockout (KO) mice showed the indispensable role of kisspeptin–GPR54 signaling on reproduction, but detailed analysis of gonadotropin release were still limited. Here we have generated Kiss1 KO rats to evaluate a role of kisspeptin on pulsatile gonadotropin secr...