Pappano W N, Scott I C, Clark T G, Eddy R L, Shows T B, Greenspan D S
Department of Biomolecular Chemistry, Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, 1300 University Avenue, Madison, Wisconsin, 53706, USA.
Genomics. 1998 Sep 1;52(2):236-9. doi: 10.1006/geno.1998.5474.
Chordin is a key developmental protein that dorsalizes early vertebrate embryonic tissues by binding to ventralizing TGF-beta-like bone morphogenetic proteins and sequestering them in latent complexes. Here we report the first characterization of mammalian chordin. The full-length cDNA sequence for mouse chordin is given, and RNA blot analysis shows the murine chordin gene Chrd to be expressed at relatively high levels in 7-day postcoitum mouse embryos and at much decreased levels at later developmental times and in adult tissues. These results imply a major role for chordin during gastrulation of the mammalian embryo. Nevertheless, both murine and human chordin genes are shown to be expressed at readily detectable levels in several fetal and adult tissues, most notably liver and cerebellum, suggesting additional roles in organogenesis and homeostasis. Chrd was mapped to mouse chromosome 16 using interspecific crosses, and the cognate human gene CHRD was localized to human chromosome 3q27 by radiation hybrid mapping.
脊索蛋白是一种关键的发育蛋白，它通过与具有腹侧化作用的TGF-β样骨形态发生蛋白结合，并将它们隔离在潜在复合物中，从而使早期脊椎动物胚胎组织背侧化。在此我们报告了哺乳动物脊索蛋白的首次特征描述。给出了小鼠脊索蛋白的全长cDNA序列，RNA印迹分析表明，小鼠脊索蛋白基因Chrd在受精后7天的小鼠胚胎中表达水平相对较高，而在发育后期和成年组织中表达水平大幅下降。这些结果表明脊索蛋白在哺乳动物胚胎原肠胚形成过程中起主要作用。然而，小鼠和人类的脊索蛋白基因在几种胎儿和成年组织中均有易于检测到的表达水平，最显著的是肝脏和小脑，这表明它们在器官发生和体内平衡中还有其他作用。利用种间杂交将Chrd定位到小鼠16号染色体上，通过辐射杂种图谱分析将同源人类基因CHRD定位到人类3号染色体q27区域。
