In the heart, unidirectional blood flow depends on proper heart valve function. As, in mammals, regulatory mechanisms of early heart valve and bone development are shown to contribute to adult heart valve pathologies, we used the animal model zebrafish (ZF, Danio rerio) to investigate the microarchitecture and differentiation of cardiac valve interstitial cells in the transition from juvenile (35 days) to end of adult breeding (2.5 years) stages. Of note, light microscopy and immunohistochemistry revealed major differences in ZF heart valve microarchitecture when compared with adult mice. We demonstrate evidence for rather chondrogenic features of valvular interstitial cells by histological staining and immunodetection of SOX-9, aggrecan, and type 2a1 collagen. Collagen depositions are enriched in a thin layer at the atrial aspect of atrioventricular valves and the ventricular aspect of bulboventricular valves, respectively. At the ultrastructural level, the collagen fibrils are lacking obvious periodicity and orientation throughout the entire valve.

中文翻译：

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正常成年斑马鱼瓣膜间质细胞的非病理性软骨形成特征。

在心脏中，单向血流取决于适当的心脏瓣膜功能。由于在哺乳动物中，显示出早期心脏瓣膜和骨骼发育的调节机制有助于成年心脏瓣膜病变，因此我们使用斑马鱼动物模型（ZF，Danio rerio）研究了过渡期心脏瓣膜间质细胞的微结构和分化从幼年（35天）到成年育种结束（2.5年）。值得注意的是，与成年小鼠相比，光学显微镜和免疫组织化学显示ZF心脏瓣膜微结构的主要差异。我们通过组织学染色和免疫检测SOX-9，聚集蛋白聚糖和2a1型胶原蛋白，证明了瓣膜间质细胞相当软骨的特征。胶原沉积物分别在房室瓣膜的房侧和房室瓣膜的心室侧富集成薄层。在超微结构水平，胶原纤维在整个瓣膜中缺乏明显的周期性和方向。