心脏不在身体的中轴线上，而是位于左胸前；肝脏则在身体的右侧。纤毛作为钙介导的机械传感器发挥作用，指示左右不对称。不动的纤毛机械地感知流体流动的方向以进行左右确定。是这些决定了人类和其他脊椎动物器官的不对称性。本二篇论文是人类等动物器官不对称发育关联基础科学研究论文。
(Baidu Translator: )
Why does the heart grow on the left? Two "Science" papers reveal the key link of movable cilia
The heart is not on the central axis of the body, but on the left chest; The liver is on the right side of the body. Cilias act as calcium-mediated mechanical sensors, indicating left and right asymmetry. The motionless cilia mechanically sense the direction of fluid flow for left and right determination. It is these that determine the asymmetry of human and other vertebrate organs. This two papers are basic scientific research papers on the relationship between asymmetric development of human and other animal organs.
（百度翻訳： ）
心臓はどうして左に生えているのですか。2編の『科学』論文の謎解きの重要な一環として移動可能な繊毛
心臓は体の中心線ではなく、左胸の前にある。肝臓は体の右側にある。繊毛はカルシウム媒介の機械センサとして機能し、左右非対称を指示する。不動の繊毛は、流体の流れの方向を機械的に感知して左右に決定する。これらが人間と他の脊椎動物器官の非対称性を決定している。本二篇の論文は人間などの動物器官の非対称発育関連基礎科学研究論文である。
学术经纬
2023/01/11
论文一
论文二
论文标题：Cilia function as calcium-mediated mechanosensors that instruct left-right asymmetry
作者：Lydia Djenoune, Mohammed Mahamdeh, Thai V. Truong, Christopher T. Nguyen, Scott E. Fraser, Martina Brueckner, Jonathon Howard, Shiaulou Yuan
期刊：Science
发表时间：2023/01/06
数字识别码：10.1126/science.abq7317
摘要：The breaking of bilateral symmetry in most vertebrates is critically dependent upon the motile cilia of the embryonic left-right organizer (LRO), which generate a directional fluid flow; however, it remains unclear how this flow is sensed. Here, we demonstrated that immotile LRO cilia are mechanosensors for shear force using a methodological pipeline that combines optical tweezers, light sheet microscopy, and deep learning to permit in vivo analyses in zebrafish. Mechanical manipulation of immotile LRO cilia activated intraciliary calcium transients that required the cation channel Polycystin-2. Furthermore, mechanical force applied to LRO cilia was sufficient to rescue and reverse cardiac situs in zebrafish that lack motile cilia. Thus, LRO cilia are mechanosensitive cellular levers that convert biomechanical forces into calcium signals to instruct left-right asymmetry.
▲可移动的纤毛（绿色）与周围的不动纤毛（粉色）（图片来源：Etiology and Morphogenesis of Congenital Heart Disease: From Gene Function and Cellular Interaction to Morphology, CC BY-NC 2.5）
该论文的共同作者Scott E. Fraser教授也指出，这些结果以及全新的研究工具为理解胚胎发育模式提供了新的机遇。同时这项研究也提醒我们，关于纤毛信号与生物力学对发育和疾病的影响，还有大量问题有待进一步研究。
封面图来源：123RF
参考资料：
[1] Lydia Djenoune et al, Cilia function as calcium-mediated mechanosensors that instruct left-right asymmetry, Science (2023). DOI: 10.1126/science.abq7317
[2] Takanobu A. Katoh et al, Immotile cilia mechanically sense the direction of fluid flow for left-right determination, Science (2023). DOI: 10.1126/science.abq8148
[3] Telling left from right: cilia as cellular force sensors during embryogenesis. Retrieved Jan. 5, 2023 from https://www.eurekalert.org/news-releases/975791
