Remodeling of the hyomandibular skeleton and facial nerve positioning during embryonic and postembryonic development of teleost fish
Remodeling of the hyomandibular skeleton and facial nerve positioning during embryonic and postembryonic development of teleost fish
复制标题
硬骨鱼胚胎和胚胎后发育过程中舌下颌骨骨骼重塑和面神经定位
DOI：
10.1016/j.ydbio.2022.06.009
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发表时间：
2022
影响因子：
2.7
通讯作者：
Wada Hironori
中科院分区：
文献类型：
--
作者：
Iwasaki Miki;Kawakami Koichi;Wada Hironori
脊椎动物骨骼在发育过程中通过软骨细胞、成骨细胞和破骨细胞的活动改变其形状。尽管人们对这些细胞的分化机制了解很多，但人们对它们如何以特定区域的方式表现以获得独特的骨骼形状却知之甚少。为了解决这个问题，我们研究了斑马鱼下颌（Hm）系统的发育。 Hm 起源于带有单个孔（Hm 孔）的软骨，面神经 (VII) 通过该孔。我们发现雪旺细胞使 VII 神经有髓鞘化，调节软骨细胞的重排以扩大 Hm 孔。然后，Hm 软骨在软骨膜中骨化，其中骨髓软骨细胞被脂肪细胞取代。然后，沿着 VII 神经的骨基质被破骨细胞吸收，形成通往骨髓的通道。随后，第七神经进入骨髓，随后沉积新的骨基质，将神经与颌肌插入隔离。成骨细胞和破骨细胞的基因消融揭示了这些细胞在重塑过程中的特定作用。有趣的是，第七神经移位并没有发生在青鳉身上；相反，与斑马鱼不同的骨沉积将 VII 神经与肌肉插入分开。我们的结果定义了骨骼重塑的新机制，通过该机制，骨骼以区域和物种特异性的方式形成。
The vertebrate skeleton changes its shape during development through the activities of chondrocytes, osteoblasts and osteoclasts. Although much is known about the mechanisms for differentiation in these cells, it is less understood how they behave in a region-specific manner to acquire unique bone shapes. To address this question, we investigated the development of the hyomandibular (Hm) system in zebrafish. The Hm originates as cartilage carrying a single foramen (the Hm foramen), through which the facial (VII) nerve passes. We reveal that Schwann cells, which myelinate the VII nerve, regulate rearrangement of the chondrocytes to enlarge the Hm foramen. The Hm cartilage then becomes ossified in the perichondrium, where the marrow chondrocytes are replaced by adipocytes. Then, the bone matrix along the VII nerve is resorbed by osteoclasts, generating a gateway to the bone marrow. Subsequent movement of the VII nerve into the marrow, followed by deposition of new bone matrix, isolates the nerve from the jaw muscle insertion. Genetic ablation of osteoblasts and osteoclasts reveals specific roles of these cells during remodeling processes. Interestingly, the VII nerve relocation does not occur in medaka; instead, bone deposition distinct from those in zebrafish separates the VII nerve from the muscle insertion. Our results define novel mechanisms for skeletal remodeling, by which the bone shapes in a region- and species-specific manner.