Evolution of the vertebrate skeleton: morphology, embryology, and development.
Evolution of the vertebrate skeleton: morphology, embryology, and development.
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DOI：
10.1186/s40851-014-0007-7
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发表时间：
2015
影响因子：
2.7
通讯作者：
Kuratani S
中科院分区：
文献类型：
--
作者：
Hirasawa T;Kuratani S
在脊椎动物的进化过程中，人们认识到两个主要的骨骼系统——内骨骼和外骨骼。在这里，我们提出这两个系统的区别主要在于它们的相对位置，而不是胚胎组织发生或细胞起源谱系的差异。比较胚胎学分析表明，两种类型的骨骼在进化过程中都改变了其组织发生模式。尽管外骨骼被认为完全由神经嵴产生，但最近对硬骨鱼的实验表明，躯干的外骨骼起源于中胚层。在许多脊椎动物中看到的釉质和牙本质涂层的颅后外骨骼似乎并不像之前假设的那样代表一种祖先状况，而是一种衍生状况，其中釉质和牙本质组织附着在骨骼上。来自盾皮鱼化石的最新数据与这种情况相符。相比之下，头骨的喙部含有神经嵴衍生的骨头。最近的发育研究表明，神经嵴衍生的骨骼和中胚层衍生的骨骼之间的界限在整个进化过程中可能并不一致。相反，骨元素的相对位置可能是保守的，并且骨元素的同源性已被保留，并且发育机制和细胞谱系发生机会性变化。
Two major skeletal systems—the endoskeleton and exoskeleton—are recognized in vertebrate evolution. Here, we propose that these two systems are distinguished primarily by their relative positions, not by differences in embryonic histogenesis or cell lineage of origin. Comparative embryologic analyses have shown that both types of skeleton have changed their mode of histogenesis during evolution. Although exoskeletons were thought to arise exclusively from the neural crest, recent experiments in teleosts have shown that exoskeletons in the trunk are mesodermal in origin. The enameloid and dentine-coated postcranial exoskeleton seen in many vertebrates does not appear to represent an ancestral condition, as previously hypothesized, but rather a derived condition, in which the enameloid and dentine tissues became accreted to bones. Recent data from placoderm fossils are compatible with this scenario. In contrast, the skull contains neural crest-derived bones in its rostral part. Recent developmental studies suggest that the boundary between neural crest- and mesoderm-derived bones may not be consistent throughout evolution. Rather, the relative positions of bony elements may be conserved, and homologies of bony elements have been retained, with opportunistic changes in the mechanisms and cell lineages of development.