Discovery of the insect-type sialic acid and its metabolic pathway

本研究的目的是证明昆虫不含有脊椎动物中常见的唾液酸（Sia），而是含有昆虫特有的“昆虫型Sia”的假设。以果蝇（Drosophilla melanogaster）、赤粉甲虫（Tribolium castaneum）等几种蛾类为研究对象，对其进行了纯化，并对其结构、发生和代谢途径进行了分析。我们可以识别出在本研究中测试的所有昆虫中存在的昆虫类型Sia。在代谢方面，并非所有昆虫都含有常见的Sia代谢酶，即使在这些含有代谢酶的昆虫中，这些酶似乎也失去了活性。然而，在不久的将来，昆虫酶能否利用昆虫型Sia将是一个紧迫的课题。综上所述，我们关于昆虫含有昆虫型Sia而不是普通Sia的假设已经被成功验证。

The objective of this study is to demonstrate the hypothesis that insects do not contain usual sialic acids (Sia) that are commonly found in vertebrates, but “insect-type Sia”, which is unique to insects. Using Drosophilla melanogaster (fluit fly), Tribolium castaneum (red flour beetle), several moth species, purification and analyses of structure, occurrence, and metabolic pathways of the insect -type Sia were performed. We could identify the insect-type Sia that was present in all the insects tested in this study. For metabolic aspects, all insects do not contain metabolic enzymes known for the common Sia, and even in such insects that were shown to contain the metabolic enzymes, the enzymes seemed to lose their activities. It would be an urgent subject, however, to see if the insect enzymes can utilize the insect-type Sia in near future. Taken together, our hypothesis that insects contain the insect-type Sia, but not the common Sia has been successfully verified.