Glycoconjugates have various functions in differentiation, development, aging and in all aspects of normal functioning of organisms. The reason for increased research on this topic is that glycoconjugates locate mostly on the cell surface and play crucial biological roles in the nervous system including brain development, synaptic plasticity, learning, and memory. Considering their roles in the nervous system, information about their existence in the insect nervous system is rather sparse. Therefore, in order to detect monosaccharide content of N- and O-glycans, we carried out capLC–ESI–MS/MS analysis to determine the concentration changes of glucose, mannose, galactose, N-acetylglucosamine (GlcNAc), N-acetylgalactosamine (GalNAc), fucose, xylose, arabinose, and ribose monosaccharides in the nervous system of Bombyx mori during development and aging processes. In addition to LC–MS, lectin blotting was done to detect quantitative changes in N- and O-glycans. Developmental stages were selected as 3rd (the youngest sample), 5th (young) larval instar, motionless prepupa (the oldest sample), and pupa (adult development). Derivatization of monosaccharides was performed with a solution of PMP agent and analyzed with capLC–ESI–MS/MS. For lectin blotting, determination of glycan types was carried out with Galanthus nivalis agglutinin and Peanut agglutinin lectins. In all stages, the most abundant monosaccharide was glucose. Although all monosaccharides were present most abundantly in the youngest stage (3rd instar), they are generally reduced gradually during the aging process. It was observed that amounts of monosaccharides increased again in the pupa stage. According to lectin blotting, N- and O-linked glycoproteins expressions were different and there were some specific glycoprotein expression differences between stages. These findings suggest that the glycosylation state of proteins in the nervous system changes during development and aging in insects in a similar fashion to that reported for vertebrates.

中文翻译：

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蚕（Bombyx mori L.）神经系统在发育和衰老过程中的单糖分布图。

糖缀合物在生物的分化，发育，衰老和正常运转的所有方面具有多种功能。对此主题进行更多研究的原因是，糖缀合物主要位于细胞表面，并在神经系统中发挥重要的生物学作用，包括大脑发育，突触可塑性，学习和记忆。考虑到它们在昆虫神经系统中的作用，关于它们在昆虫神经系统中的存在的信息很少。因此，为了检测N-和O-聚糖的单糖含量，我们进行了capLC–ESI–MS / MS分析，以确定葡萄糖，甘露糖，半乳糖，N-乙酰氨基葡萄糖（GlcNAc），N-家蚕神经系统发育和衰老过程中的-乙酰半乳糖胺（GalNAc），岩藻糖，木糖，阿拉伯糖和核糖单糖。除LC-MS外，还进行了凝集素印迹分析，以检测N-和O-聚糖的定量变化。选择发育阶段为第三龄（最年轻的样本），第五龄（幼年）的幼虫龄，不动产前pu（最老的样本）和（成人发育）。用PMP试剂溶液进行单糖衍生化，并使用capLC–ESI–MS / MS进行分析。对于凝集素印迹，用雪花莲（Galanthus nivalis）进行聚糖类型的测定凝集素和花生凝集素凝集素。在所有阶段中，最丰富的单糖是葡萄糖。尽管所有单糖都在最年轻的阶段（三龄）中含量最高，但在衰老过程中通常会逐渐减少。观察到that期单糖的含量再次增加。根据凝集素印迹，N-和O-连接的糖蛋白表达是不同的，并且在各阶段之间存在一些特定的糖蛋白表达差异。这些发现表明，在昆虫的发育和衰老过程中，神经系统中蛋白质的糖基化状态以与脊椎动物报道的相似的方式发生变化。