Pectoral fin and girdle development in the basal Actinopterygians Polyodon spathula and Acipenser transmontanus
Pectoral fin and girdle development in the basal Actinopterygians Polyodon spathula and Acipenser transmontanus
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DOI：
10.1002/jmor.10264
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发表时间：
2004-11-01
影响因子：
1.5
通讯作者：
Force, A
中科院分区：
文献类型：
--
作者：
Davis, MC;Shubin, NH;Force, A
鲟形目胸鳍的内骨骼与硬骨鱼类的鳍辐和四足动物的肢骨相似。在这里，我们提出了一个胸鳍发育的北美白鲟，多齿鲟，和白色鲟鱼，西伯利亚鲟，这表明，硬骨鱼和四足动物内骨骼图案机制方面存在于鲟形目。这些元素被认为是同源的硬骨鱼桡骨，propterygium和mesopterygial桡骨，形成通过细分的最初软骨形成板的间充质细胞称为内骨骼盘。在鲟形目中，与肌翼类后鳍片同源的成分作为内骨骼的副产物从内骨骼盘单独发育。延伸到鳍芽后缘的肩带。在四足动物中，延长的后翼状胬肉和后翼状胬肉桡骨从最初的非软骨形成间充质以近端到远端的顺序形成离散的浓缩物。在鲟形目鳍中看到的变异模式也与假定的同源性相关：所有来自“正常”鳍的变异只涉及后鳍和后鳍桡鳍。区分多齿鱼和鲟鳍鱼发育的主要因素是内骨骼细胞外基质的组成。蛋白聚糖（可见与阿尔新蓝）和II型胶原蛋白（可视化免疫组织化学）分泌在不同的地方内的鳍元素和腰带的间充质原基，并在不同的发展时间。鲟形胸鳍与硬骨鱼类的鳍不同之处在于内骨骼和皮射线的相对贡献。多齿鱼和鲟的鳍具有精细的内骨骼，这些内骨骼通过真皮鳞毛沿着它们的远端边缘重叠。与此相反，硬骨鱼鳍通常具有相对较小的内骨骼桡骨，与真皮鳍骨架末端连接，很少或没有proximodistal重叠。(C)2004 Wiley-Liss，Inc.
The pectoral fins of Acipenseriformes possess endoskeletons with elements homologous to both the fin radials of teleosts and the limb bones of tetrapods. Here we present a study of pectoral fin development in the North American paddlefish, Polyodon spathula, and the white sturgeon, Acipenser transmontanus, which reveals that aspects of both teleost and tetrapod endoskeletal patterning mechanisms are present in Acipenseriformes. Those elements considered homologous to teleost radials, the propterygium and the mesopterygial radials, form via subdivision of an initially chondrogenic plate of mesenchymal cells called the endoskeletal disc. In Acipenseriformes, elements homologous to the sarcopterygian metapterygium develop separately from the endoskeletal disc as an outgrowth of the endoskeletal. shoulder girdle that extends into the posterior margin of the finbud. As in tetrapods, the elongating metapterygium and the metapterygial radials form in a proximal to distal order as discrete condensations from initially nonchondrogenic mesenchyme. Patterns of variation seen in the Acipenseriform fin also correlate with putative homology: all variants from the "normal" fin bauplan involved the metapterygium and the metapterygial radials alone. The primary factor distinguishing Polyodon and Acipenser fin development from each other is the composition of the endoskeletal extracellular matrix. Proteoglycans (visualized with Alcian Blue) and Type II collagen (visualized by immunohistochemistry) are secreted in different places within the mesenchymal anlage of the fin elements and girdle and at different developmental times. Acipenseriform pectoral fins differ from the fins of teleosts in the relative contribution of the endoskeleton and dermal rays. The fins of Polyodon and Acipenser possess elaborate endoskeletons overlapped along their distal margins by dermal lepidotrichia. In contrast, teleost fins generally possess relatively small endoskeletal radials that articulate with the dermal fin skeleton terminally, with little or no proximodistal overlap. (C) 2004 Wiley-Liss, Inc.