Animal Magnetism

A photosensitive protein behind the retinas of cockroaches plays a role in light-dependent, directional magnetosensitivity.

Catherine Offord
May 1, 2016

CRY IN THE EYE: The cryptochrome Cry2, involved in magnetosensing, is present in the eyes of two cockroach species, including Blattella germanica (above). © ISTOCK.COM/ERIKKARITS


The Paper
O. Bazalova et al., “Cryptochrome 2 mediates directional magnetoreception in cockroaches,” PNAS, doi:10.1073/pnas.1518622113, 2016.

Protein with a Purpose
Many animals make use of light-dependent sensitivity to magnetic fields (MFs) to navigate their environment. Researchers recently implicated cryptochrome 1 (Cry1)—a photosensitive protein involved in circadian clock function in Drosophila—in fruit fly magnetoreception. This led David Dolezel of the Institute of Entomology at the Czech Academy of Sciences and colleagues to ask whether Cry2, a vertebrate-type cryptochrome also present in many insects, mediates sensitivity to the presence and directionality of MFs in other animals.

Restless Roaches
Previously, the investigators found that two cockroach species with Cry2 become more restless when subjected to rotating (rather than...