The evolution and conservation of left-right patterning mechanisms
The evolution and conservation of left-right patterning mechanisms
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DOI：
10.1242/dev.100560
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发表时间：
2014-04-15
期刊：
影响因子：
4.6
通讯作者：
Schweickert, Axel
中科院分区：
文献类型：
--
作者：
Blum, Martin;Feistel, Kerstin;Schweickert, Axel
形态不对称是动物身体结构的一个常见特征，从蜗牛的壳盘绕到人类的器官放置。信号蛋白 Nodal 是确定这种偏侧性的关键。许多脊椎动物，包括人类，在胚胎发育过程中利用纤毛打破对称性：旋转纤毛产生向左流动的细胞外液，从而诱导 Nodal 的不对称表达。相比之下，在无脊椎动物中，节点不对称可以独立于流动引起。在这里，我们要问心流何时以及为何演变。我们认为，流动存在于后口动物的基部，并且需要在其他完全双边对称的脊椎动物中维持器官不对称。
Morphological asymmetry is a common feature of animal body plans, from shell coiling in snails to organ placement in humans. The signaling protein Nodal is key for determining this laterality. Many vertebrates, including humans, use cilia for breaking symmetry during embryonic development: rotating cilia produce a leftward flow of extracellular fluids that induces the asymmetric expression of Nodal. By contrast, Nodal asymmetry can be induced flow-independently in invertebrates. Here, we ask when and why flow evolved. We propose that flow was present at the base of the deuterostomes and that it is required to maintain organ asymmetry in otherwise perfectly bilaterally symmetrical vertebrates.