Minařík Martin, Campbell Alexander S, Franěk Roman, Vazačová Michaela, Havelka Miloš, Gela David, Pšenička Martin, Baker Clare V H
Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.
Faculty of Fisheries and Protection of Waters, University of South Bohemia in České Budějovice, Vodňany, Czech Republic.
Elife. 2025 Jun 25;14. doi: 10.7554/eLife.96285.
In electroreceptive jawed fishes and amphibians, individual lateral line placodes form lines of neuromasts on the head containing mechanosensory hair cells, flanked by fields of ampullary organs containing electroreceptors - modified hair cells that respond to weak electric fields. Extensively shared gene expression between neuromasts and ampullary organs suggests that conserved molecular mechanisms are involved in their development, but a few transcription factor genes are restricted either to the developing electrosensory or mechanosensory lateral line. Here, we used CRISPR/Cas9-mediated mutagenesis in G0-injected sterlet embryos (, a sturgeon) to test the function of three such genes. We found that the 'hair cell' transcription factor gene is required for both hair cell and electroreceptor differentiation in sterlet, and for and expression in both neuromasts and ampullary organs. These data support the conservation of developmental mechanisms between hair cells and electroreceptors. Targeting ampullary organ-restricted did not yield any phenotype, potentially owing to redundancy with other genes that we found to be expressed in sterlet ampullary organs. After targeting mechanosensory-restricted , ampullary organs formed within neuromast lines, suggesting that Foxg1 normally represses their development, whether directly or indirectly. We speculate that electrosensory organs may be the 'default' developmental fate of lateral line primordia in electroreceptive vertebrates.
在具有电感应能力的有颌鱼类和两栖动物中，单个侧线原基在头部形成神经丘线，其中包含机械感觉毛细胞，两侧是壶腹器官区域，壶腹器官含有电感受器——一种经过修饰的毛细胞，可对弱电场做出反应。神经丘和壶腹器官之间广泛共享的基因表达表明，保守的分子机制参与了它们的发育，但一些转录因子基因仅限于发育中的电感应或机械感觉侧线。在这里，我们在G0期注射的小体鲟胚胎（一种鲟鱼）中使用CRISPR/Cas9介导的诱变来测试三个此类基因的功能。我们发现，“毛细胞”转录因子基因对于小体鲟中毛细胞和电感受器的分化以及在神经丘和壶腹器官中的和表达都是必需的。这些数据支持了毛细胞和电感受器之间发育机制的保守性。靶向壶腹器官特异性的没有产生任何表型，这可能是由于与我们发现在小体鲟壶腹器官中表达的其他基因存在冗余。在靶向机械感觉特异性的之后，壶腹器官在神经丘线内形成，这表明Foxg1通常会直接或间接地抑制它们的发育。我们推测，电感应器官可能是电感应脊椎动物侧线原基的“默认”发育命运。
