We show for the first time endoskeletal regeneration in the developing pectoral fin of zebrafish. The developing pectoral fin contains an aggregation plate of differentiated chondrocytes (endochondral disc; primordium for endoskeletal components, proximal radials). The endochondral disc can be regenerated after amputation in the middle of the disc. The regenerated disc sufficiently forms endoskeletal patterns. Early in the process of regenerating the endochondral disc, epithelium with apical ectodermal ridge (AER) marker expression rapidly covers the amputation plane, and mesenchymal cells start to actively proliferate. Taken together with re-expression of a blastema marker gene, msxb, and other developmental genes, it is likely that regeneration of the endochondral disc recaptures fin development as epimorphic limb regeneration does. The ability of endoskeletal regeneration declines during larval growth, and adult zebrafish eventually lose the ability to regenerate endoskeletal components such that amputated endoskeletons become enlarged. Endoskeletal regeneration in the zebrafish pectoral fin will serve as a new model system for successful appendage regeneration in mammals.

中文翻译：

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斑马鱼可在幼虫的胸鳍中再生内骨骼，但再生能力下降。

我们第一次显示了斑马鱼的胸鳍发育中的骨骼内再生。发育中的胸鳍包含分化的软骨细胞的聚集板（软骨内盘；骨骼内成分的原基，radial骨近端）。椎间盘中段截肢后可再生软骨内盘。再生的椎间盘足以形成骨骼内模式。在软骨内盘的再生过程的早期，具有顶端外胚层（AER）标志物表达的上皮迅速覆盖截肢平面，并且间充质细胞开始活跃增殖。再加上胚泡标志物基因，msxb和其他发育基因的重新表达，软骨内盘的再生很可能像表观肢体再生一样捕获了鳍的发育。幼虫生长期间内骨骼再生能力下降，成年斑马鱼最终失去再生内骨骼成分的能力，使截肢的内骨骼变大。斑马鱼胸鳍的骨骼内再生将成为哺乳动物成功进行肢体再生的新模型系统。