García-Castro M I, Vielmetter E, Bronner-Fraser M
Division of Biology 139-74, California Institute of Technology, Pasadena, CA 91125, USA.
Science. 2000 May 12;288(5468):1047-51. doi: 10.1126/science.288.5468.1047.
Within the bilaterally symmetric vertebrate body plan, many organs develop asymmetrically. Here, it is demonstrated that a cell adhesion molecule, N-cadherin, is one of the earliest proteins to be asymmetrically expressed in the chicken embryo and that its activity is required during gastrulation for proper establishment of the left-right axis. Blocking N-cadherin function randomizes heart looping and alters the expression of Snail and Pitx2, later components of the molecular cascade that regulate left-right asymmetry. However, the expression of other components of this cascade (Nodal and Lefty) was unchanged after blocking N-cadherin function, suggesting the existence of parallel pathways in the establishment of left-right morphogenesis. Here, the results suggest that N-cadherin-mediated cell adhesion events are required for establishment of left-right asymmetry.
在两侧对称的脊椎动物身体结构中,许多器官不对称发育。在此研究中表明,一种细胞黏附分子N-钙黏着蛋白是鸡胚胎中最早不对称表达的蛋白质之一,并且在原肠胚形成期间,其活性对于正确建立左右轴是必需的。阻断N-钙黏着蛋白的功能会使心脏环化随机化,并改变Snail和Pitx2的表达,这两者是调节左右不对称性的分子级联反应中较靠后的成分。然而,在阻断N-钙黏着蛋白功能后,该级联反应其他成分(Nodal和Lefty)的表达并未改变,这表明在左右形态发生的建立过程中存在平行途径。此处结果表明,N-钙黏着蛋白介导的细胞黏附事件对于左右不对称性的建立是必需的。