Grob Robin, Wegmann Johanna W, Rössler Wolfgang, Fleischmann Pauline N
Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, 97074 Würzburg, Germany; Department of Biology, Faculty of Natural Sciences, Norwegian University of Science and Technology, 7034 Trondheim, Norway.
Behavioral Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, 97074 Würzburg, Germany; AG Neurosensorik/Animal Navigation, Institute of Biology and Environmental Sciences, Faculty V, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany.
Curr Biol. 2024 Dec 16;34(24):5833-5838.e2. doi: 10.1016/j.cub.2024.11.012. Epub 2024 Dec 6.
Spatial orientation based on the geomagnetic field (GMF) is a widespread phenomenon in the animal kingdom, predominantly observed in long-distance migrating birds, sea turtles, lobsters, and Lepidoptera. Although magnetoreception has been studied intensively, the mechanism remains elusive. A crucial question for a mechanistic understanding of magnetoreception is whether animals rely on inclination or polarity-based magnetic information. Inclination-based magnetic orientation utilizes the angle between the magnetic field lines and gravity, indicating poleward and equatorward. In contrast, polarity-based magnetic orientation allows animals to detect the polarity of the GMF, the north and south direction of the field vector. Cataglyphis desert ants are excellent experimental models for testing whether magnetic inclination or polarity of the magnetic field is used for navigation. Desert ants are solitary foragers with exceptional navigational skills. When the ants leave their underground nest for the first time to become foragers, they perform learning walks for up to three days to learn the visual panorama and calibrate their compass systems. The ants repeatedly stop their forward movement during learning walks for performing turns (pirouettes), interrupted by stopping phases. Gaze directions during the longest stopping phases are directed toward the nest entrance. We experimentally manipulated look-back behavior systematically by altering polarity or inclination of the GMF. We demonstrate that Cataglyphis ants, contrary to most other insects studied, possess a polarity-sensitive magnetic compass, making them ideal experimental models for narrowing down the evidence for particle-based mechanisms underlying magnetosensation in this insect.
基于地磁场（GMF）的空间定向是动物界中一种普遍存在的现象，主要在长途迁徙的鸟类、海龟、龙虾和鳞翅目昆虫中观察到。尽管对磁感受进行了深入研究，但其机制仍然难以捉摸。对于磁感受机制理解的一个关键问题是动物是依赖基于倾角还是基于极性的磁信息。基于倾角的磁定向利用磁场线与重力之间的夹角，指示向极和向赤道方向。相比之下，基于极性的磁定向使动物能够检测地磁场的极性，即场矢量的南北方向。箭蚁是测试磁场的磁倾角或极性是否用于导航的优秀实验模型。沙漠蚂蚁是具有非凡导航技能的独居觅食者。当蚂蚁首次离开地下巢穴成为觅食者时，它们会进行长达三天的学习行走，以了解视觉全景并校准其罗盘系统。在学习行走过程中，蚂蚁会反复停止向前移动以进行转弯（旋转），中间穿插停止阶段。最长停止阶段的注视方向指向巢穴入口。我们通过改变地磁场的极性或倾角来系统地实验操纵回头行为。我们证明，与大多数其他研究过的昆虫不同，箭蚁拥有一个对极性敏感的磁罗盘，这使它们成为缩小这种昆虫磁感受基于粒子机制证据范围的理想实验模型。
