LAUSR

Received: Revised: Accepted: Published online: July 10, 2017 February 15, 2018 February 18, 2018 March 28, 2018 The relationship between kisspeptin and GnRH releasing in many species has been studied including post-pubertal buffalo, but not in pre-pubertal buffalo. The aims of this study were to detect the localization of Kiss1mRNA and the distribution of kisspeptin protein in the preoptic (POA) and arcuate (ARC) hypothalamic nuclei of pre-pubertal swamp buffaloes. Brains were collected from ten pre-pubertal female buffaloes (<1 year, 1-1.5 years, 1.5-2 years, 2-2.5 years and 2.5-3 years; two animals each age) and processed for paraffin blocks. Four-micron paraffin sections of the POA and ARC hypothalamic nuclei were prepared. The present research found evidence of Kiss1 mRNA in the cytoplasm of the neuronal soma and some small neuronal cells using the in-situ hybridization technique in all ten heifers. Using the immunohistochemistry technique, kisspeptin proteins expressed a weak intensity in the cellular process of neurons. The distribution of kisspeptin immunoreactions were found mainly in the POA hypothalamic nucleus in the juvenile group (<1 years) and only in the ARC area in the 1-2.5 years old prepubertal group. However, there was no kisspeptin reaction in both hypothalamic nuclei in the 2.5-3 years (peri-pubertal) group (P<0.01). This study provides evidence of Kiss1 mRNA and kisspeptin protein in the hypothalamus of prepubertal buffaloes. This suggests that kisspeptin may be involved in reproductive development and may influence puberty onset in swamp buffalo heifers. ©2018 PVJ. All rights reserved