Evidence for the existence of a functional Kiss1/Kiss1 receptor pathway in fish.
In mammals, the Kiss1 receptor (Kiss1r) and its kisspeptin ligands are key factors regulating the onset of puberty. In fish, however, the mechanisms underlying the initiation of puberty are poorly understood and the role of the Kiss1r/kisspeptin pathway in this process has not been established. In this study, a bioinformatics approach was used to identify the genes for Kiss1 and Kiss1r in five teleost genomes and the information used to clone the corresponding transcripts from zebrafish. Zebrafish kiss1r was expressed predominantly in the brain, with a minor level of expression in the eye, and zebrafish kiss1 was expressed in brain, intestine, adipose tissue and testis. Analysis of the chromosome region containing the kiss1 locus showed high synteny across vertebrate genomes. In contrast to their mammalian homologues, teleost Kiss1 protein sequences were poorly conserved with the exception of the region representing kisspeptin-10. Signal peptide sequences and likely cleavage and amidation sites in the teleost Kiss1 sequences were determined and found to be similar to those in mammalian Kiss1. This is the first report of the existence and characterization of the Kiss1 gene outside the mammalian taxa, suggesting that a functional Kiss1/Kiss1 receptor pathway is conserved across vertebrate species.
van Aerle
R
R
Environmental and Molecular Fish Biology, School of Biosciences, Hatherly Laboratories, University of Exeter, Devon EX4 4PS, UK. r.van-aerle@exeter.ac.uk <r.van-aerle@exeter.ac.uk>
Kille
P
P
Lange
A
A
Tyler
C R
CR
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005091:Exons; D005260:Female; D006801:Humans; D059648:Kisspeptins; D008297:Male; D008969:Molecular Sequence Data; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D000074502:Receptors, Kisspeptin-1; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016415:Sequence Alignment; D014018:Tissue Distribution; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics*
C527845:Kiss1 protein, zebrafish; D059648:Kisspeptins; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D025521:Tumor Suppressor Proteins; D029961:Zebrafish Proteins; C527848:kiss1ra protein, zebrafish