Screening planarians for magnetite-based magnetoreceptors via SR-XRF

Magnetoreception, the ability to perceive geomagnetic fields, is known from various animals, including planarians. The mechanism of magnetoreception, however, is still unknown and several hypothesis are discussed. Present data supports the hypothesis that magnetic particles, like single domain crystals of magnetite (Fe3O4), are involved in magnetoreception in planarians. We suggest to screen sections of Planarians for iron deposits in specific regions of interest (ROIs) using SR-XRF. In these regions magnetic signature has been measured using MRI-QSM. Elemental mapping will allow us to test if the magnetic signature (QSM) correlates with the presence of iron, which would be indicative of magnetite-based magnetoreception. This data will provide the basis for ultrastructural investigations, immunohistological characterization and magnetic measurements of the particles to test whether they are suitable candidates for the long sought after magnetoreceptors.