Larsson Manne, Balk Lennart, Dahlgren Elin, Vryonidis Efstathios, Lindqvist Dennis
Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
Department of Aquatic Resources, Institute of Freshwater Research, Swedish University of Agriculture, SE-178 93 Drottningholm, Sweden.
ACS Omega. 2024 Sep 27;9(40):41703-41710. doi: 10.1021/acsomega.4c05862. eCollection 2024 Oct 8.
Thiamine deficiency is a large contributor to reduced reproduction success among salmonids throughout the northern hemisphere. In Scandinavia, this reproduction disorder is known as M74; while in North America, it is known as early mortality syndrome (EMS). The disorder fluctuates in magnitude from year to year. During years with high prevalence of the disorder, salmonid hatcheries that stock various aquatic systems to maintain the population size experience difficulties filling their quotas without thiamine treatment of alevins. The disorder is monitored both by observing the survival rate and by measuring the thiamine content of prefertilized eggs in the hatcheries. Here, a simple extraction procedure is presented, which allows for quantitative determination of the various phosphorylated forms of thiamine using liquid chromatography mass spectrometry but also allows for extraction in 96 deep-well plates and measurement of the total thiamine content using fluorescence monitoring with a plate reader, following oxidation of thiamine to thiochrome. The latter procedure could also be integrated into a highly portal system where the thiochrome is determined using the DeNovix QFX analyzer. The newly developed extraction procedure and cleanup method for fluorescence measurement represent the most versatile and simple methods to date for monitoring of thiamine in salmonid eggs. The methods produced accurate and precise data with quantification limits below the limit where the deficiency causes 100% lethality.
硫胺素缺乏是导致北半球鲑科鱼类繁殖成功率降低的一个主要因素。在斯堪的纳维亚半岛，这种繁殖障碍被称为M74；而在北美，它被称为早期死亡综合征（EMS）。这种障碍的严重程度逐年波动。在该障碍高发的年份，为维持种群数量而向各种水生系统投放鲑科鱼苗的孵化场，如果不对仔鱼进行硫胺素处理，就难以完成配额。通过观察存活率和测量孵化场中受精前鱼卵的硫胺素含量来监测这种障碍。在此，介绍一种简单的提取程序，该程序不仅可以使用液相色谱质谱法对硫胺素的各种磷酸化形式进行定量测定，还可以在96孔深孔板中进行提取，并在硫胺素氧化为硫色素后，使用酶标仪通过荧光监测来测量总硫胺素含量。后一种程序也可以集成到一个高度自动化的系统中，使用DeNovix QFX分析仪测定硫色素。新开发的用于荧光测量的提取程序和净化方法是迄今为止监测鲑科鱼卵中硫胺素最通用、最简单的方法。这些方法产生了准确和精确的数据，其定量限低于缺乏症导致100%致死率的限度。
