Structure, Synthesis, and Phylogeny of Kisspeptin and its Receptor - Kisspeptin Signaling in Reproductive Biology - page 10

Fig. 2.2 Both Kiss1 and Kiss2 activate both Gpr54-1 and Gpr54-2 in Xenopus and zebrafi sh.
Although the relative potency differs among different receptor subtypes, Kiss1 or Kiss2 longer
than 10 amino acid residues show activation at physiological concentrations, suggesting that Kiss1
and Kiss2 are the ligands for Gpr54-1 and Gpr54-2. Luciferase assay. Adapted with permission
from Lee YR, Tsunekawa K, Moon MJ, Um HN, Hwang JI, et al. (2009) Molecular evolution of
multiple forms of kisspeptins and GPR54 receptors in vertebrates. Endocrinology 150: 2837-
2846. 2009 © Endocrine Society
peptides, including the kisspeptins, share only a small number of conservative
sequences in common. Therefore, to unveil the phylogenetic relationship of certain
genes among or within species, especially for shorter peptides, the synteny analysis
will often give us powerful evidence for such relationship. It can be used to predict
if certain genes in the other species are the homologous gene or just analogous ones
by chance.
In genetics, synteny describes the physical co-localization of genes in a certain
genetic locus. Recent synteny analysis of kisspeptin genes proposes that kiss1 and
kiss2 are paralogous to each other and that they have arisen as a result of gene
duplication at the locus level. The synteny analysis of kiss1 and kiss2 genes in sev-
eral vertebrate species strongly suggested that kiss1 and kiss2 are duplicated together
with some surrounding genes such as golt1a / b , plekha5 / 6 , pik3c2b / cg , and etnk1 / 2