Table1_The effect of hypomagnetic field on survival and mitochondrial functionality of active Paramacrobiotus experimentalis females and males of different age.DOCX

Even for tardigrades, often called the toughest animals on Earth, a hypomagnetic field (HMF) is an extreme environment. However, studies on the effect of HMF on tardigrades and other invertebrates are scarce. Mitochondria play an important role in an organism’s response to extreme conditions. The effect of HMF on the mitochondrial inner membrane potential (Δψ), a well-known marker of mitochondria functionality, shows that mitochondria are very sensitive to HMF. To measure the HMF effect on Paramacrobiotus experimentalis, we calculated the tardigrade survival rate and Δψ level after HMF treatments of different durations. We also estimated the relationship between the age and sex of the tardigrade and the HMF effect. We observed age- and sex-related differences in Δψ and found that Δψ changes after HMF treatment were dependent on its duration as well as the animal’s age and sex. Furthermore, active P. experimentalis individuals displayed a high survival rate after HMF treatment. The data may contribute to the understanding of tardigrade aging and their resistance to extreme conditions including HMF, which in turn may be useful for future space explorations.

即便对于常被称为地球上最强韧动物的缓步动物（tardigrades，俗称水熊虫）而言，低磁环境（hypomagnetic field, HMF）也属于极端环境。然而，目前针对低磁环境对缓步动物及其他无脊椎动物影响的研究仍较为匮乏。线粒体（mitochondria）在生物体应对极端环境的过程中发挥着关键作用。低磁环境对线粒体内膜电位（mitochondrial inner membrane potential, Δψ）——这一公认的线粒体功能标志物——的影响表明，线粒体对低磁环境极为敏感。为探究低磁环境对实验副嗜脂缓步虫（Paramacrobiotus experimentalis）的影响，本研究对不同时长低磁处理后的缓步动物存活率及Δψ水平进行了测算，同时分析了缓步动物的年龄、性别与低磁环境效应之间的关联。本研究观测到Δψ水平存在与年龄、性别相关的差异，同时发现低磁处理后的Δψ变化程度取决于处理时长以及受试动物的年龄与性别。此外，经低磁处理后，活力正常的P. experimentalis个体仍保持较高存活率。本研究所得数据有助于深化对缓步动物衰老过程及其对包括低磁环境在内的极端环境的抗性的理解，而该研究成果未来或可为深空探索提供助力。