Gene structure analysis of kisspeptin-2 (Kiss2) in the Senegalese sole (Solea senegalensis): Characterization of two splice variants of Kiss2, and novel evidence for metabolic regulation of kisspeptin signaling in non-mammalian species

► We present novel evidence indicating that kisspeptin may link energy balance and reproduction. ► We determined the gene structure of kisspeptin in the Senegalese sole, which has only one paralogous gene, Kiss2. ► We detected two Ss Kiss2 isoforms generated by alternative splicing through intronic retention. ► Ss Kiss2_v1 produces the functional protein, while Ss Kiss2_v2 codes for a non-functional protein. ► Fasting increased hypothalamic mRNA levels of Ss Kiss2_v1 and Ss LH and Ss FSH mRNA the pituitary.