Expression of Timeless and Cryptochrome in Crustaceans

Circadian rhythms are endogenously-driven biological cycles with periods of approximately 24 hours and influence many systems and processes in the body of an organism. Many circadian rhythm components, like the proteins timeless (TIM), crytopchrome (CRY), and clock (CLK), are phylogenetically conserved in organisms as diverse as Drosophila and humans. Drosophila has been studied extensively, with the best-characterized clock mechanisms. Crustacean circadian rhythms have not been studied extensively, and the molecular underpinnings are largely unknown. Uca pugilator brains were dissected and split into 3 major areas (A. olfactory/optic regions, B. antennal lobe, and C. accessory lobe). X organs were also dissected from Uca eyestalks. Cells from these regions were cultured for a minimum of 24 hours before fixing. Whole brains were also examined. Initial results indicate putative CLK immunolabeling occurs prominently in Cluster 6 of the fiddler crab brain, a region implicated in the regulation of crustacean circadian rhythms. Additionally, CRY cytoplasmic staining was elevated at mid-scotophase compared with mid-photophase, consistent with findings in Drosophila [3]. We are currently studying the timing differences in the presence of the other circadian proteins including TIM and CLK.