Liu Jing-Xia, Kahsay Abraha, Dennhag Nils, von Hofsten Jonas, Pedrosa Domellöf Fatima
Department of Medical and Translational Biology, Umeå University, Umeå, Sweden.
Department of Clinical Sciences, Ophthalmology, Umeå University, Umeå, Sweden.
Invest Ophthalmol Vis Sci. 2025 Apr 1;66(4):77. doi: 10.1167/iovs.66.4.77.
We have previously described a novel type of multiterminal en plaque motor endplates in the human extraocular muscles (EOMs). This study aimed to investigate whether multiterminal en plaque motor endplates are conserved in EOMs among vertebrates.
The motor endplates were identified with α-bungarotoxin (α-BTx) and antibodies against synaptic proteins and neurofilament in the EOMs of zebrafish, rabbits and mice. Transcriptomic data were re-analyzed to identify acetylcholine receptor (AChR) subunits in EOMs and trunk muscles of wild-type zebrafish at five and 20 months of age.
In addition to the two typical types of single en plaque and multiple en grappe motor endplates, the third type of multiterminal en plaque motor endplates were observed in the EOMs of zebrafish, rabbits, and mice. The EOMs of zebrafish showed a significantly higher proportion of myofibers containing multiterminal en plaque motor endplates compared to EOMs of rabbits and mice. RNA sequencing data revealed significantly higher AChR subunits in the zebrafish EOMs compared to trunk muscles.
Multiterminal en plaque motor endplates are not exclusive to human EOMs but are also present in the EOMs of other vertebrate species, suggesting a conserved feature of the EOMs.
我们之前描述了人类眼外肌（EOMs）中一种新型的多终板斑块状运动终板。本研究旨在调查多终板斑块状运动终板在脊椎动物的眼外肌中是否保守存在。
在斑马鱼、兔子和小鼠的眼外肌中，用α-银环蛇毒素（α-BTx）以及针对突触蛋白和神经丝的抗体来识别运动终板。重新分析转录组数据，以鉴定5月龄和20月龄野生型斑马鱼的眼外肌和躯干肌肉中的乙酰胆碱受体（AChR）亚基。
除了两种典型的单斑块状和多葡萄状运动终板类型外，在斑马鱼、兔子和小鼠的眼外肌中还观察到了第三种类型的多终板斑块状运动终板。与兔子和小鼠的眼外肌相比，斑马鱼的眼外肌中含有多终板斑块状运动终板的肌纤维比例显著更高。RNA测序数据显示，斑马鱼眼外肌中的AChR亚基明显高于躯干肌肉。
多终板斑块状运动终板并非人类眼外肌所特有，在其他脊椎动物物种的眼外肌中也存在，这表明眼外肌具有保守特征。
