Cryptochrome 2 necessary for magnetosensitivity of American cockroach Periplaneta americana.
|Year of publication||2011|
|MU Faculty or unit|
|Description||Cryptochromes (CRYs) – proteins that have been postulated to generate radical pairs sensitive to geomagnetic field and facilitate light-dependent compass sense of animals – mediate magnetoreception in fruit fly (Gegear et al., 2008; 2010). Using Cry deficient and transgenic flies the authors showed that Drosophila magnetosensitivity relies on both drosophila-like CRY type 1 and vertebrate-like CRY 2. Here, we combined reverse genetics approach with non-conditioning behavioral assay of enhanced movement activity (restlessness) under magnetic North shifts on insect Periplaneta americana. We investigated the impact of cry2 gene silencing (by means of RNA interference). We identified CRY 2 as the only Cryptochrome in Periplaneta, prepared dsRNA and injected into cockroaches. After 15 days, decline CRY mRNA levels (i) together with disruption of circadian rhythms (ii) and loss of the magnetosensory reaction (iii) showed that CRY2 is necessary both for circadian rhythms control and for magnetic sensitivity in Periplaneta. Disrupting the molecular clock itself under constant light or by silencing tim gene did not affect the magnetic sensitivity. Hence, behavioral response to magnetic stimuli was dependent on unsuppressed CRY2 production selectively. Since the assay depends on no learned skills and uses natural intensities of geomagnetic field our findings give evidence of specific role for Cryptochrome 2 in insect magnetoreception.|