Laboratory of Fish Diseases, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Parasitology. 2023 Sep;150(10):939-949. doi: 10.1017/S0031182023000768. Epub 2023 Aug 11.
is an industrially significant protozoan parasite of Manila clam, . So far, various media, based on Dulbecco's Modified Eagle Medium and Ham's F-12 nutrient mixture with supplementation of fetal bovine serum (FBS), have been developed to proliferate the parasitizing trophozoite stage of . The present study showed that did not proliferate in FBS-deficient Perkinsus broth medium (PBMΔF), but proliferated well in PBMΔF supplemented with tissue extract of host Manila clams, indicating that FBS and Manila clam tissue contained molecule(s) required for proliferation. Preliminary characterization suggested that the host-derived molecule(s) was a heat-stable molecule(s) with a molecular weight of less than 3 kDa, and finally a single molecule required for the proliferation was purified by high-performance liquid chromatography processes. High-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance analyses identified this molecule as glycine betaine (=trimethylglycine), and the requirement of this molecule for proliferation was confirmed by an assay using chemically synthesized, standard glycine betaine. Although glycine betaine was required for the proliferation of all examined species, supplementation of glycine betaine precursors, such as choline and betaine aldehyde, enhanced the proliferation of 4 species ( and ), but not of 2 others ( and ). Thus, it was concluded that the ability to biosynthesise glycine betaine from its precursors varied among species, and that and lack the ability required to biosynthesize glycine betaine for proliferation.
是一种具有重要工业意义的马尼拉蛤的原生动物寄生虫。到目前为止，已经开发了各种基于杜尔贝科改良鹰培养基和哈姆氏 F-12 营养混合物的培养基，并添加胎牛血清（FBS），以增殖寄生的滋养体阶段。本研究表明，在缺乏 FBS 的 Perkinsus 肉汤培养基（PBMΔF）中，不会增殖，但在补充宿主马尼拉蛤组织提取物的 PBMΔF 中增殖良好，表明 FBS 和马尼拉蛤组织中含有增殖所需的分子。初步特征表明，宿主来源的分子是一种热稳定的分子，分子量小于 3 kDa，最后通过高效液相色谱过程纯化出增殖所需的单一分子。高分辨率电喷雾电离质谱和核磁共振分析将这种分子鉴定为甘氨酸甜菜碱（=三甲胺基乙酸），并且通过使用化学合成的标准甘氨酸甜菜碱进行的测定证实了这种分子对增殖的要求。尽管甘氨酸甜菜碱是所有检查的物种增殖所必需的，但甘氨酸甜菜碱前体，如胆碱和甜菜醛的补充增强了 4 个物种（和）的增殖，但另外 2 个物种（和）则不然。因此，可以得出结论，从其前体生物合成甘氨酸甜菜碱的能力在物种之间有所不同，并且和缺乏增殖所需的生物合成甘氨酸甜菜碱的能力。
