The presence of N-acetylneuraminic acid in Malpighian tubules of larvae of the cicada Philaenus spumarius
The presence of N-acetylneuraminic acid in Malpighian tubules of larvae of the cicada Philaenus spumarius
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DOI：
10.1023/a:1007115627708
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发表时间：
1999-11-01
影响因子：
3
通讯作者：
Schauer, R
中科院分区：
文献类型：
--
作者：
Malykh, YN;Krisch, B;Schauer, R
含唾液酸的糖结合物通常被认为是后口动物所特有的，后口动物是动物王国的一个谱系，包括从棘皮动物到脊椎动物。然而，有两个单独的报告表明，唾液酸存在于昆虫物种黑腹果蝇和梅隆鸡尾草中。由于昆虫被归类为原口动物，这些发现对先前关于系统发育分布和唾液酸进化的假设提出了质疑。在这里，我们报告了N-乙酰神经氨酸(Neu5Ac)在蝉幼虫中的存在。用接骨木和黄血竭的凝集素对幼虫切片的细胞化学分析表明，马氏管的固结液泡中含有唾液酸。针对聚唾液酸的单抗MAb 735标记了相同的结构。对唾液酸衍生物的高效液相色谱和气相色谱-质谱仪进行的化学分析提供了确凿的证据证明Neu5Ac在Spumarius Philaenus幼虫中的存在。这些数据表明，在这只蝉中，Neu5Ac存在于α2，8连接的聚唾液酸结构和α2，6连接的结构中。这些结果提供了进一步的证据，证明在昆虫中存在唾液酸，以及在后口来源的糖共轭中存在已知的连接。
Sialic acid-containing glycoconjugates are generally considered to be unique to the deuterostomes, a lineage of the animal kingdom which includes animals from the echinoderms up to the vertebrates. There are, however, two isolated reports of sialic acid occurring in the insect species Drosophila melanogaster and Galleria mellonella. Since insects are classified as protostomes, these findings call previous assumption on the phylogenetic distribution and thus on the evolution of sialic acids into question. Here, we report the occurrence of N-acetylneuraminic acid (Neu5Ac) in larvae of the cicada Philaenus spumarius. Cytochemical analysis of larval sections with lectins from Sambucus nigra and Limax flavus suggested the presence of sialic acids in the concrement vacuoles of the Malpighian tubules. The monoclonal antibody MAb 735, which is specific for polysialic acid, labelled the same structures. A chemical analysis performed by HPLC of fluorescent derivatives of sialic acids and by GLC-MS provided sound evidence for the presence of Neu5Ac in the Philaenus spumarius larvae. These data suggest that in this cicada Neu5Ac occurs in alpha 2,8-linked polysialic acid structures and in alpha 2,6-linkages. The results provide further evidence for the existence of sialic acids in insects and in linkages known to occur in glycoconjugates of deuterostomate origin.