Klonisch T, Froehlich C, Tetens F, Fischer B, Hombach-Klonisch S
Department of Anatomy and Cell Biology, Martin Luther University Faculty of Medicine, Halle/Saale, Germany.
Mol Biol Evol. 2001 Mar;18(3):393-403. doi: 10.1093/oxfordjournals.molbev.a003815.
Employing comparative analysis of the cDNA-coding sequences of the unique preprorelaxin of the Afro-lorisiform Galago crassicaudatus and the Malagasy lemur Varecia variegata and the relaxin-like factor (RLF) of G. crassicaudatus, we demonstrated distinct differences in the dynamics of molecular remodeling of both hormones during primate evolution. The lorisiform and lemuriform preprorelaxin sequences encoded identical hormones, providing the first endocrinological evidence for the monophyletic origin of all Strepsirrhini. Structural analysis revealed the lemuriform members of the relaxin family to be potentially bioactive single-gene products. In contrast to the "two-prong" relaxin receptor-binding motif (RELVR) present within the B-domains of other primate relaxins, strepsirrhine relaxin contained a unique "three-prong" motif (RRLIR) with highest sequence homology to the receptor-binding motif of the evolutionarily much older skate relaxin. In contrast to relaxin, the RLF molecule was highly conserved during primate evolution and contained within its B-domain the putative relaxin receptor-binding motif and a pentameric sequence implicated in binding to specific RLF receptors. Mutually exclusive expression of strepsirrhine preprorelaxin and RLF were observed in the fetal villous trophoblast cells of the strepsirrhine placenta and postpubertal testicular Leydig cells, respectively, reflecting distinct functional roles for both hormones within the reproductive tract of Strepsirrhini.
通过对非洲懒猴科粗尾婴猴独特的前松弛素原和马达加斯加狐猴黑白领狐猴的cDNA编码序列以及粗尾婴猴的松弛素样因子（RLF）进行比较分析，我们证明了在灵长类动物进化过程中这两种激素分子重塑动态存在明显差异。懒猴科和狐猴科的前松弛素原序列编码相同的激素，为所有原猴亚目的单系起源提供了首个内分泌学证据。结构分析表明，松弛素家族的狐猴科成员可能是具有生物活性的单基因产物。与其他灵长类动物松弛素B结构域中存在的“双叉”松弛素受体结合基序（RELVR）不同，原猴亚目的松弛素含有独特的“三叉”基序（RRLIR），与进化上古老得多的鳐鱼松弛素的受体结合基序具有最高的序列同源性。与松弛素不同，RLF分子在灵长类动物进化过程中高度保守，并且在其B结构域中包含假定的松弛素受体结合基序和一个与特定RLF受体结合有关的五聚体序列。分别在原猴亚目胎盘的胎儿绒毛滋养层细胞和青春期后睾丸的间质细胞中观察到原猴亚目前松弛素和RLF的相互排斥表达，这反映了这两种激素在原猴亚目生殖道中的不同功能作用。
