Bainbridge C, Clites B L, Caldart C S, Palacios B, Rollins K, Golombek D A, Pierce J T, Vidal-Gadea A G
School of Biological Sciences, Illinois State University, Normal, IL, USA.
Department of Neuroscience, University of Texas at Austin, Austin, TX, USA.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2020 May;206(3):343-352. doi: 10.1007/s00359-019-01364-y. Epub 2019 Aug 28.
Magnetoreceptive animals orient to the earth's magnetic field at angles that change depending on temporal, spatial, and environmental factors such as season, climate, and position within the geomagnetic field. How magnetic migratory preference changes in response to internal or external stimuli is not understood. We previously found that Caenorhabditis elegans orients to magnetic fields favoring migrations in one of two opposite directions. Here we present new data from our labs together with replication by an independent lab to test how temporal, spatial, and environmental factors influence the unique spatiotemporal trajectory that worms make during magnetotaxis. We found that worms gradually change their average preferred angle of orientation by ~ 180° to the magnetic field during the course of a 90-min assay. Moreover, we found that the wild-type N2 strain prefers to orient towards the left side of a north-facing up, disc-shaped magnet. Lastly, similar to some other behaviors in C. elegans, we found that magnetic orientation may be more robust in dry conditions (< 50% RH). Our findings help explain why C. elegans accumulates with distinct patterns during different periods and in differently shaped magnetic fields. These results provide a tractable system to investigate the behavioral genetic basis of state-dependent magnetic orientation.
具有磁感受能力的动物会根据时间、空间以及环境因素（如季节、气候和在地磁场中的位置）的变化，以不同角度朝向地球磁场。目前尚不清楚磁迁移偏好如何响应内部或外部刺激而发生变化。我们之前发现秀丽隐杆线虫会朝向磁场，偏好朝两个相反方向之一迁移。在此，我们展示了来自我们实验室的新数据，并由一个独立实验室进行了重复实验，以测试时间、空间和环境因素如何影响线虫在趋磁过程中形成的独特时空轨迹。我们发现，在90分钟的实验过程中，线虫会逐渐将其平均偏好的磁场朝向角度改变约180°。此外，我们发现野生型N2菌株更喜欢朝向朝北向上的圆盘形磁铁的左侧。最后，与秀丽隐杆线虫的其他一些行为类似，我们发现干燥条件（相对湿度<50%）下磁定向可能更强。我们的研究结果有助于解释为什么秀丽隐杆线虫在不同时期和不同形状的磁场中会以不同模式聚集。这些结果为研究状态依赖型磁定向的行为遗传基础提供了一个易于处理的系统。
