First evidence of chitin as a component of the skeletal fibers of marine sponges.: Part I.: Verongidae (Demospongia: porifera)
First evidence of chitin as a component of the skeletal fibers of marine sponges.: Part I.: Verongidae (Demospongia: porifera)
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DOI：
10.1002/jez.b.21156
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发表时间：
2007-07-15
影响因子：
2.2
通讯作者：
Worch, Hartmut
中科院分区：
文献类型：
--
作者：
Ehrlich, Hermann;Maldonado, Manuel;Worch, Hartmut
海绵动物通常被认为是最古老、现存的后生动物门，也具有祖先阶段，因为大多数特征出现在高等动物中。海绵中没有甲壳素，除了由高度衍生的淡水类群产生的特殊抵抗体的壁外，这是令人费解的，因为它指出甲壳素是特定海绵家族的同型，而不是后生动物世系中的祖先条件。通过对两种绒毛虫(Aplysina sp.)的内部蛋白(海绵蛋白)骨架的观察，发现两种蠕虫的内部蛋白质(海绵蛋白)骨架结构不同。我们使用了广泛的技术(傅里叶变换红外光谱(FTIR)、拉曼光谱、X射线光谱、硫代荧光白染色、免疫标记和几丁质酶试验)，证明了几丁质是这些解脊椎动物骨骼纤维最外层(角质层)的组成部分。FTIR和拉曼光谱以及X射线衍射图一致地表明，海绵甲壳素更接近于其他动物已知的甲壳素，而不是β-甲壳素。这些发现支持以下观点，即甲壳素生产系统的出现是后生动物的祖先条件，而a-甲壳素是动物的原始形式。
The Porifera (sponges) are often regarded as the oldest, extant metazoan phylum, also bearing the ancestral stage for most features occurring in higher animals. The absence of chitin in sponges, except for the wall of peculiar resistance bodies produced by a highly derived fresh-water group, is puzzling, since it points out chitin to be an autapomorphy for a particular sponge family rather than the ancestral condition within the metazoan lineage. By investigating the internal proteinaceous (spongin) skeleton of two demosponges (Aplysina sp. and Verongula gigantea) using a wide array of techniques (Fourier transform infrared (FTIR), Raman, X-ray, Calcofluor White Staining, Immunolabeling, and chitinase test), we show that chitin is a component of the outermost layer (cuticle) of the skeletal fibers of these demosponges. FTIR and Raman spectra, as well as X-ray difractograms consistently revealed that sponge chitin is much closer to the alpha-chitin known from other animals than to P-chitin. These findings support the view that the occurrence of a chitin-producing system is the ancestral condition in Metazoa, and that the a-chitin is the primitive form in animals.