1. Jiangsu Key Laboratory of Marine Bioresources and Environment /Jiangsu Key Laboratory of Marine Biotechnology School of Marine Science and Fisheries, Jiangsu Ocean University, Lianyungang 222005, China.
2. Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
Yi Chuan. 2023 Jun 20;45(6):488-500. doi: 10.16288/j.yczz.23-044.
Left-right asymmetry is an essential feature in bilateral animals. The mechanism underlying the left-right asymmetrical organ morphogenesis is a central question in developmental biology. Studies in vertebrates show that left-right asymmetry formation needs three essential steps: the initial left-right symmetry breaking, the left-right asymmetrical gene expression, and the left-right asymmetrical organ morphogenesis. Many vertebrates use cilia to produce directional fluid flow to break symmetry during embryonic development, asymmetric Nodal-Pitx2 signaling to pattern the left-right asymmetry, and and other genes to control the morphogenesis of asymmetrical organs. In invertebrates, there are left-right mechanisms independent of cilia and even others more different from that of vertebrates. In this review, we summarize the major steps and relevant molecular mechanisms of left-right asymmetric development in vertebrates and invertebrates, aiming to provide a reference for the understanding of the origin and evolution of the left-right developmental mechanism.
左右不对称是双侧动物的一个基本特征。左右不对称器官形态发生的机制是发育生物学中的一个核心问题。脊椎动物的研究表明，左右不对称的形成需要三个基本步骤：最初的左右对称破缺、左右不对称基因表达和左右不对称器官形态发生。许多脊椎动物在胚胎发育过程中利用纤毛产生定向的流体流动来打破对称性，不对称的 Nodal-Pitx2 信号来模式化左右不对称，以及其他基因来控制不对称器官的形态发生。在无脊椎动物中，存在独立于纤毛的左右机制，甚至还有更多不同于脊椎动物的机制。在这篇综述中，我们总结了脊椎动物和无脊椎动物左右不对称发育的主要步骤和相关分子机制，旨在为理解左右发育机制的起源和进化提供参考。
