Evidence for two distinct KiSS genes in non-placental vertebrates that encode kisspeptins with different gonadotropin-releasing activities in fish and mammals.
Kisspeptins, the products of KiSS-1 gene, have recently emerged as fundamental regulators of reproductive function in different mammalian and, presumably, non-mammalian species. To date, a single form of KiSS-1 has been described in mammals, and recently, in several fish species and Xenopus. We report herein the cloning and characterization of two distinct KiSS-like genes, namely, KiSS-1 and KiSS-2, in the teleost sea bass. While KiSS-1 encodes a peptide identical to rodent kisspeptin-10, the predicted KiSS-2 decapeptide diverges at 4 amino acids (FNFNPFGLRF). Genome database searches showed that both genes are present in non-placental vertebrate genomes. Indeed, phylogenetic and genome mapping analyses suggest that KiSS-1 and KiSS-2 are paralogous genes that originated by duplication of an ancestral gene, although KiSS-2 is lost in placental mammals. KiSS-1 and KiSS-2 mRNAs are present in brain and gonads of sea bass, medaka and zebrafish. Comparative functional studies demonstrated that KiSS-2 decapeptide was significantly more potent than KiSS-1 peptide in inducing LH and FSH secretion in sea bass. In contrast, KiSS-2 decapeptide only weakly elicited LH secretion in rats, whereas KiSS-1 peptide was maximally effective. Our data are the first to provide conclusive evidence for the existence of a second KiSS gene, KiSS-2, in non-placental vertebrates, whose product is likely to play a dominant stimulatory role in the regulation of the gonadotropic axis at least in teleosts.
Felip
Alicia
A
Consejo Superior de Investigaciones Científicas, Instituto de Acuicultura de Torre de la Sal, Ribera de Cabanes, 12595 Castellón, Spain.
Zanuy
Silvia
S
Pineda
Rafael
R
Pinilla
Leonor
L
Carrillo
Manuel
M
Tena-Sempere
Manuel
M
Gómez
Ana
A
D000375:Aging; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D005260:Female; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006065:Gonadotropins, Pituitary / Q000097:blood; D059648:Kisspeptins; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D009990:Oryzias / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction / Q000235:genetics*; D012621:Seasons; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D026801:Synteny; D013997:Time Factors; D014714:Vertebrates / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D029941:Fish Proteins; D006065:Gonadotropins, Pituitary; C491406:Kiss1 protein, rat; C527845:Kiss1 protein, zebrafish; D059648:Kisspeptins; D011506:Proteins; D029961:Zebrafish Proteins