The ability to perceive geomagnetic fields (GMFs) represents a fascinating biological phenomenon. Studies on transgenic flies have provided evidence that photosensitive Cryptochromes (Cry) are involved in the response to magnetic fields (MFs). However, none of the studies tackled the problem of whether the Cry-dependent magnetosensitivity is coupled to the sole MF presence or to the direction of MF vector. In this study, we used gene silencing and a directional MF to show that mammalian-like Cry2 is necessary for a genuine directional response to periodic rotations of the GMF vector in two insect species. Longer wavelengths of light required higher photon fluxes for a detectable behavioral response, and a sharp detection border was present in the cyan/green spectral region. Both observations are consistent with involvement of the FADox, FAD(•-) and FADH(-) redox forms of flavin. The response was lost upon covering the eyes, demonstrating that the signal is perceived in the eye region. Immunohistochemical staining detected Cry2 in the hemispherical layer of laminal glia cells underneath the retina. Together, these findings identified the eye-localized Cry2 as an indispensable component and a likely photoreceptor of the directional GMF response. Our study is thus a clear step forward in deciphering the in vivo effects of GMF and supports the interaction of underlying mechanism with the visual system.

• Klíčová slova
• circadian genes, cryptochrome, light spectrum, locomotor activity, magnetoreception,
• MeSH
• fenotyp MeSH
• fotoreceptory bezobratlých metabolismus   účinky záření   MeSH
• kryptochromy metabolismus   MeSH
• magnetické pole * MeSH
• složené oko členovců účinky záření   MeSH
• švábi metabolismus   účinky záření   MeSH
• ultrafialové záření MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kryptochromy MeSH

Animal eyes are morphologically diverse. Their assembly, however, always relies on the same basic principle, i.e., photoreceptors located in the vicinity of dark shielding pigment. Cnidaria as the likely sister group to the Bilateria are the earliest branching phylum with a well developed visual system. Here, we show that camera-type eyes of the cubozoan jellyfish, Tripedalia cystophora, use genetic building blocks typical of vertebrate eyes, namely, a ciliary phototransduction cascade and melanogenic pathway. Our findings indicative of parallelism provide an insight into eye evolution. Combined, the available data favor the possibility that vertebrate and cubozoan eyes arose by independent recruitment of orthologous genes during evolution.

• MeSH
• biologické modely MeSH
• Cercopithecus aethiops MeSH
• cilie metabolismus   ultrastruktura   MeSH
• COS buňky MeSH
• Cubozoa růst a vývoj   MeSH
• fotoreceptory bezobratlých cytologie   metabolismus   ultrastruktura   MeSH
• krystaliny metabolismus   MeSH
• melaniny metabolismus   MeSH
• messenger RNA MeSH
• molekulární sekvence - údaje MeSH
• obratlovci růst a vývoj   MeSH
• oči cytologie   růst a vývoj   ultrastruktura   MeSH
• oční čočka metabolismus   MeSH
• pigmentace MeSH
• regulace genové exprese MeSH
• sekvenční homologie nukleových kyselin MeSH
• transkripční faktor spojený s mikroftalmií genetika   metabolismus   MeSH
• tyčinkové opsiny metabolismus   MeSH
• zrak genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Intramural MeSH
• Názvy látek
• krystaliny MeSH
• melaniny MeSH
• messenger RNA MeSH
• transkripční faktor spojený s mikroftalmií MeSH
• tyčinkové opsiny MeSH

Migratory monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate to their overwintering grounds in Mexico. Although polarized light is one of the celestial cues used for orientation, the spectral content (color) of that light has not been fully explored. We cloned the cDNAs of three visual pigment-encoding opsins (ultraviolet [UV], blue, and long wavelength) and found that all three are expressed uniformly in main retina. The photoreceptors of the polarization-specialized dorsal rim area, on the other hand, are monochromatic for the UV opsin. Behavioral studies support the importance of polarized UV light for flight orientation. Next, we used clock protein expression patterns to identify the location of a circadian clock in the dorsolateral protocerebrum of butterfly brain. To provide a link between the clock and the sun compass, we identified a CRYPTOCHROME-staining neural pathway that likely connects the circadian clock to polarized light input entering brain.

• MeSH
• cirkadiánní rytmus fyziologie   MeSH
• exprese genu MeSH
• fotoreceptory bezobratlých metabolismus   MeSH
• fylogeneze MeSH
• hybridizace in situ MeSH
• imunohistochemie MeSH
• migrace zvířat fyziologie   MeSH
• motýli fyziologie   MeSH
• mozek fyziologie   MeSH
• nervové dráhy fyziologie   MeSH
• polymerázová řetězová reakce MeSH
• proteiny CLOCK MeSH
• retina metabolismus   MeSH
• sluneční záření MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• tyčinkové opsiny genetika   metabolismus   MeSH
• ultrafialové záření MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• srovnávací studie MeSH
• Názvy látek
• proteiny CLOCK MeSH
• trans-aktivátory MeSH
• tyčinkové opsiny MeSH