Furuhashi Takeshi, Beran Anton, Blazso Marianne, Czegeny Zsuzsanna, Schwarzinger Clemens, Steiner Gerhard
Emerging Focus Molecular Phylogenetics, Department of Evolutionary Biology, University of Vienna.
Biosci Biotechnol Biochem. 2009 Jan;73(1):93-103. doi: 10.1271/bbb.80498. Epub 2009 Jan 7.
Chitin is an insoluble component in the shells of several molluscan species. It is thought to play important roles, in biomineralization and shell structure. To date, however, reports are scarce and sometimes contradictory, and suffer from methodological problems. Only in a single cephalopod species has the chitin been identified as beta-chitin. We present data on chitin occurrence in 22 species of shell-bearing Mollusca (Conchifera) and Polyplacophora, including the first evidence for scaphopods, based on pyrolysis gas chromatography, mass spectrometry (GC-MS), and infrared spectroscopy (IR). Pyrolysis GC-MS detected chitin in every tested member of the Conchifera. IR spectroscopy before and after chitinase treatment revealed at least three distinct patterns of peak changes. The contents of the insoluble shell organics included not only chitin and proteins, but also insoluble polysaccharides, e.g., glucan. We conclude that chitin was present in the last common ancestor of the Conchifera and that its abundance in the shell matrix depends on the differentiation of the shell.
几丁质是几种软体动物外壳中的一种不溶性成分。人们认为它在生物矿化和外壳结构中发挥着重要作用。然而，迄今为止，相关报道稀少，有时还相互矛盾，且存在方法学问题。仅在一种头足类动物中，几丁质被鉴定为β-几丁质。我们基于热解气相色谱、质谱（GC-MS）和红外光谱（IR），展示了22种带壳软体动物（双壳纲）和多板纲动物中几丁质存在情况的数据，包括掘足纲动物的首个证据。热解GC-MS在双壳纲的每一个测试成员中都检测到了几丁质。几丁质酶处理前后的红外光谱显示出至少三种不同的峰变化模式。不溶性外壳有机物的成分不仅包括几丁质和蛋白质，还包括不溶性多糖，如葡聚糖。我们得出结论，几丁质存在于双壳纲的最后一个共同祖先中，并且其在外壳基质中的丰度取决于外壳的分化。
