Kiss1 and its receptor: molecular characterization and immunolocalization in the hypothalamus and corpus luteum of the buffalo.

ABSTARCT The neuropeptide kisspeptin (Kp) through its receptor Kiss1r regulates the HPG axis by controlling GnRH release. Since buffalo is a seasonal breeder with problems of delayed puberty and postpartum anestrus, we characterized the Kiss1 and Kiss1r and investigated the immunolocalization in the hypothalamus and corpus luteum (CL). Kiss1 and Kiss1r genes were amplified from gDNA covering the coding region, cloned and sequenced with accession numbers MF168937 and MG820539, respectively. The Kiss1 DNA sequence had two exonic segment contained coding sequence (cds); 408 bp encoding a predicted protein of 136 aa with conservation of Kp-10 and shared 94.5-98.3% identity with ruminants. Kiss1r DNA sequence consisted of five exons with a cds of 1134 bp encoding a protein of 378 aa. Phylogenetic analysis of Kiss1 and Kiss1r revealed that it formed a monophyletic clade with cattle, which branched from sheep and goat. Immunofluorescence study revealed the presence of Kiss1 and Kiss1r in the neuronal soma and perinuclear area of preoptic and arcuate regions of the hypothalamus and luteal cells of the CL. This is the first report on molecular characterization of bubaline Kiss1 and Kiss1r genes that confirmed the presence of conserved Kp-10 like other ruminants and kisspeptinergic system is present in the hypothalamus and CL.