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L-Cry
Facts (12)
Sources
How Lunar Cycles Guide the Spawning of Sea Creatures smithsonianmag.com Mar 8, 2023 12 facts
claimThe L-Cry protein in bristle worms consists of two protein strands bound together, with each half containing a light-absorbing structure called a flavin.
measurementPhotoreduction, a light-induced chemical reaction in the L-Cry protein, occurs after four hours of exposure to dim moonlight and reaches a maximum after six hours of continuous exposure.
claimThe L-Cry protein can respond to light intensities spanning five orders of magnitude, allowing it to react to both strong sunlight and dim moonlight due to the differing light sensitivity of its two flavin structures.
claimResearchers do not yet know the specific biological signals transmitted by the different cellular locations of L-Cry molecules in marine bristleworms.
accountKristin Tessmar-Raible's research group investigated the role of cryptochromes in the lunar timing of bristle worms by focusing on a specific cryptochrome protein called L-Cry.
claimScientists state that while the L-Cry protein is essential for discriminating between sunlight and moonlight in marine bristleworms, other light-sensing molecules are also involved.
claimIn marine bristleworms, fully photoreduced L-Cry proteins are located in the cytoplasm where they are destroyed, while partly photoreduced L-Cry proteins are located in the nucleus.
claimThe authors of a 2022 report conclude that the L-Cry protein mechanism in marine bristleworms functions as a highly sensitive low-light sensor for moonlight detection and a less sensitive high-light sensor for sunlight detection.
claimBristle worms possessing the L-Cry protein were more discerning and synchronized their lunar clocks more accurately when nighttime lighting conditions closely matched their natural environment.
claimMarine bristleworms use a combination of signals from the r-Opsin sensor and the L-Cry protein to determine the precise time to rise to the surface and release gametes on spawning nights.
claimIn laboratory experiments, bristle worms lacking the L-Cry protein failed to discriminate appropriately between light cycles, synchronizing to artificial lunar cycles that did not match natural conditions.
quoteKristin Tessmar-Raible and coauthors describe the L-Cry protein in bristle worms as a 'natural light interpreter' in a 2023 overview of rhythms in marine creatures published in the Annual Review of Marine Science.