Hu Guangwei, Li Guang, Wang Hui, Wang Yiquan
State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, Fujian 361102, China.
State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiangan District, Xiamen, Fujian 361102, China
Development. 2017 Dec 15;144(24):4694-4703. doi: 10.1242/dev.157172. Epub 2017 Nov 9.
Correct patterning of left-right (LR) asymmetry is essential during the embryonic development of bilaterians. Hedgehog (Hh) signaling is known to play a role in LR asymmetry development of mouse, chicken and sea urchin embryos by regulating expression. In this study, we report a novel regulatory mechanism for in LR asymmetry development of amphioxus embryos. Our results revealed that embryos abolish () transcription, with bilaterally symmetric expression of , and In consequence, mutants duplicated left-side structures and lost right-side characters, displaying an abnormal bilaterally symmetric body plan. These LR defects in morphology and gene expression could be rescued by mRNA injection. Our results indicate that participates in amphioxus LR patterning by controlling gene expression. Curiously, however, upregulation of Hh signaling failed to alter the expression pattern or LR morphology in amphioxus embryos, indicating that Hh might not provide an asymmetric cue for expression. In addition, is required for mouth opening in amphioxus, hinting at a homologous relationship between amphioxus and vertebrate mouth development.
左右（LR）不对称的正确模式在两侧对称动物的胚胎发育过程中至关重要。已知刺猬信号通路（Hh）通过调节表达在小鼠、鸡和海胆胚胎的LR不对称发育中发挥作用。在本研究中，我们报道了文昌鱼胚胎LR不对称发育中的一种新的调控机制。我们的结果显示，文昌鱼胚胎中缺失了（）转录，、和呈双侧对称表达。因此，突变体复制了左侧结构并失去了右侧特征，呈现出异常的双侧对称身体模式。通过注射mRNA可以挽救这些在形态和基因表达上的LR缺陷。我们的结果表明，通过控制基因表达参与文昌鱼的LR模式形成。然而，奇怪的是，Hh信号通路的上调未能改变文昌鱼胚胎中的表达模式或LR形态，这表明Hh可能不为的表达提供不对称线索。此外，文昌鱼开口需要，这暗示了文昌鱼与脊椎动物口发育之间的同源关系。
