Skutschas Pavel P, Baleeva Nataly V
Department of Vertebrate Zoology, Saint Petersburg State University, Faculty of Biology and Soil Sciencies, Universitetskaya nab. 7/9, Saint Petersburg 199034, Russian Federation.
J Morphol. 2012 Sep;273(9):1031-41. doi: 10.1002/jmor.20041. Epub 2012 Jun 18.
The development of spinal cord supports (bony thickenings which extend into the vertebral canal of vertebrae) in primitive (Salamandrella keyserlingii) and derived (Lissotriton vulgaris) salamanders were described. The spinal cord supports develop as the protuberances of periostal bone of the neural arches in the anteroproximal part of the septal collagenous fibers which connect a transverse myoseptum with the notochord and spinal cord, in the septal bundle inside the vertebral canal. Spinal cord supports were also found in some teleostean (Salmo salar, Oncorhynchus mykiss) and dipnoan (Protopterus sp.) fishes. The absence of the spinal cord supports in vertebrates with cartilaginous vertebrae (lampreys, chondrichthyan, and chondrostean fishes) corresponds to the fact that the spinal cord supports are bone structures. The absence of the spinal cord supports in frogs correlates with the lack of the well developed septal bundles inside the vertebral canal. The spinal cord supports are, presumably, a synapomorphic character for salamanders which originated independently of those observed in teleostean and dipnoan fishes.
描述了原始蝾螈(极北小鲵)和衍生蝾螈(普通滑螈)脊髓支撑结构(延伸至椎骨椎管内的骨质增厚)的发育情况。脊髓支撑结构是在椎管内的隔束中,作为连接横向肌隔与脊索和脊髓的隔胶原纤维近端前部神经弓骨膜的突起而发育形成的。在一些硬骨鱼类(大西洋鲑、虹鳟)和肺鱼类(非洲肺鱼属)中也发现了脊髓支撑结构。软骨脊椎动物(七鳃鳗、软骨鱼类和硬骨鱼类)中没有脊髓支撑结构,这与脊髓支撑结构是骨结构这一事实相符。青蛙中没有脊髓支撑结构与椎管内缺乏发育良好的隔束有关。脊髓支撑结构大概是蝾螈的一个共源性状,其起源独立于硬骨鱼类和肺鱼类中观察到的那些结构。