Fernald R D, White R B
Program in Neuroscience, Stanford University, Stanford, California, 94305-2130, USA.
Front Neuroendocrinol. 1999 Jul;20(3):224-40. doi: 10.1006/frne.1999.0181.
Gonadotropin-releasing hormone (GnRH, previously called leutinizing hormone-releasing hormone, LHRH) is the final common signaling molecule used by the brain to regulate reproduction in all vertebrates. Recently, genes encoding two other GnRH forms have been discovered. Here we present a phylogenetic analysis that shows that the GnRH genes fall naturally into three distinct branches, each of which shares not only a molecular signature but also characteristic expression sites in the brain. The GnRH genes appear to have arisen through gene duplication from a single ancestral GnRH whose origin predates vertebrates. Several lines of data support this suggestion, including the fact that all three genes share an identical exonic structure. The existence of three distinct GnRH families suggests a new, natural nomenclature for the genes, and in addition, we present a logical proposal for naming the peptide sequences. The two recently discovered GnRH genes are unusual because they encode decapeptides that are identical in all the species in which they have been found. The control of gene expression also differs among the three gene families as might be expected since they have had separate evolutionary trajectories for perhaps 500 million years.
促性腺激素释放激素（GnRH，以前称为促黄体生成素释放激素，LHRH）是大脑用于调节所有脊椎动物生殖的最终共同信号分子。最近，编码另外两种GnRH形式的基因被发现。在此，我们进行了系统发育分析，结果表明GnRH基因自然地分为三个不同的分支，每个分支不仅共享一个分子特征，还共享大脑中的特征性表达位点。GnRH基因似乎是通过基因复制从单个祖先GnRH产生的，其起源早于脊椎动物。几条数据支持这一观点，包括所有三个基因共享相同外显子结构这一事实。三个不同的GnRH家族的存在为这些基因提出了一种新的、自然的命名法，此外，我们还提出了一个命名肽序列的合理建议。最近发现的两个GnRH基因不同寻常，因为它们编码的十肽在所有已发现它们的物种中都是相同的。正如预期的那样，由于这三个基因家族可能已经有了大约5亿年的独立进化轨迹，它们的基因表达调控也有所不同。
