@article{DeppischHelfrichFoersterSenthilan2022,
  author    = {Deppisch, Peter and Helfrich-F{\"o}rster, Charlotte and Senthilan, Pingkalai R.},
  title     = {The gain and loss of cryptochrome/photolyase family members during evolution},
  series = {Genes},
  volume    = {13},
  journal   = {Genes},
  number    = {9},
  doi       = {10.3390/genes13091613},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312873},
  year      = {2022},
  abstract  = {The cryptochrome/photolyase (CRY/PL) family represents an ancient group of proteins fulfilling two fundamental functions. While photolyases repair UV-induced DNA damages, cryptochromes mainly influence the circadian clock. In this study, we took advantage of the large number of already sequenced and annotated genes available in databases and systematically searched for the protein sequences of CRY/PL family members in all taxonomic groups primarily focusing on metazoans and limiting the number of species per taxonomic order to five. Using BLASTP searches and subsequent phylogenetic tree and motif analyses, we identified five distinct photolyases (CPDI, CPDII, CPDIII, 6-4 photolyase, and the plant photolyase PPL) and six cryptochrome subfamilies (DASH-CRY, mammalian-type MCRY, Drosophila-type DCRY, cnidarian-specific ACRY, plant-specific PCRY, and the putative magnetoreceptor CRY4. Manually assigning the CRY/PL subfamilies to the species studied, we have noted that over evolutionary history, an initial increase of various CRY/PL subfamilies was followed by a decrease and specialization. Thus, in more primitive organisms (e.g., bacteria, archaea, simple eukaryotes, and in basal metazoans), we find relatively few CRY/PL members. As species become more evolved (e.g., cnidarians, mollusks, echinoderms, etc.), the CRY/PL repertoire also increases, whereas it appears to decrease again in more recent organisms (humans, fruit flies, etc.). Moreover, our study indicates that all cryptochromes, although largely active in the circadian clock, arose independently from different photolyases, explaining their different modes of action.},
  language  = {en}
}
@article{ColizziBeerCutietal.2021,
  author    = {Colizzi, Francesca Sara and Beer, Katharina and Cuti, Paolo and Deppisch, Peter and Mart{\´i}nez Torres, David and Yoshii, Taishi and Helfrich-F{\"o}rster, Charlotte},
  title     = {Antibodies Against the Clock Proteins Period and Cryptochrome Reveal the Neuronal Organization of the Circadian Clock in the Pea Aphid},
  series = {Frontiers in Physiology},
  volume    = {12},
  journal   = {Frontiers in Physiology},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2021.705048},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242909},
  year      = {2021},
  abstract  = {Circadian clocks prepare the organism to cyclic environmental changes in light, temperature, or food availability. Here, we characterized the master clock in the brain of a strongly photoperiodic insect, the aphid Acyrthosiphon pisum, immunohistochemically with antibodies against A. pisum Period (PER), Drosophila melanogaster Cryptochrome (CRY1), and crab Pigment-Dispersing Hormone (PDH). The latter antibody detects all so far known PDHs and PDFs (Pigment-Dispersing Factors), which play a dominant role in the circadian system of many arthropods. We found that, under long days, PER and CRY are expressed in a rhythmic manner in three regions of the brain: the dorsal and lateral protocerebrum and the lamina. No staining was detected with anti-PDH, suggesting that aphids lack PDF. All the CRY1-positive cells co-expressed PER and showed daily PER/CRY1 oscillations of high amplitude, while the PER oscillations of the CRY1-negative PER neurons were of considerable lower amplitude. The CRY1 oscillations were highly synchronous in all neurons, suggesting that aphid CRY1, similarly to Drosophila CRY1, is light sensitive and its oscillations are synchronized by light-dark cycles. Nevertheless, in contrast to Drosophila CRY1, aphid CRY1 was not degraded by light, but steadily increased during the day and decreased during the night. PER was always located in the nuclei of the clock neurons, while CRY was predominantly cytoplasmic and revealed the projections of the PER/CRY1-positive neurons. We traced the PER/CRY1-positive neurons through the aphid protocerebrum discovering striking similarities with the circadian clock of D. melanogaster: The CRY1 fibers innervate the dorsal and lateral protocerebrum and putatively connect the different PER-positive neurons with each other. They also run toward the pars intercerebralis, which controls hormone release via the neurohemal organ, the corpora cardiaca. In contrast to Drosophila, the CRY1-positive fibers additionally travel directly toward the corpora cardiaca and the close-by endocrine gland, corpora allata. This suggests a direct link between the circadian clock and the photoperiodic control of hormone release that can be studied in the future.},
  language  = {en}
}
@article{SchlichtingRiegerCusumanoetal.2018,
  author    = {Schlichting, Matthias and Rieger, Dirk and Cusumano, Paola and Grebler, Rudi and Costa, Rodolfo and Mazzotta, Gabriella M. and Helfrich-F{\"o}rster, Charlotte},
  title     = {Cryptochrome interacts with actin and enhances eye-mediated light sensitivity of the circadian clock in Drosophila melanogaster},
  series = {Frontiers in Molecular Neuroscience},
  volume    = {11},
  journal   = {Frontiers in Molecular Neuroscience},
  number    = {238},
  doi       = {10.3389/fnmol.2018.00238},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177086},
  year      = {2018},
  abstract  = {Cryptochromes (CRYs) are a class of flavoproteins that sense blue light. In animals, CRYs are expressed in the eyes and in the clock neurons that control sleep/wake cycles and are implied in the generation and/or entrainment of circadian rhythmicity. Moreover, CRYs are sensing magnetic fields in insects as well as in humans. Here, we show that in the fruit fly Drosophila melanogaster CRY plays a light-independent role as "assembling" protein in the rhabdomeres of the compound eyes. CRY interacts with actin and appears to increase light sensitivity of the eyes by keeping the "signalplex" of the phototransduction cascade close to the membrane. By this way, CRY also enhances light-responses of the circadian clock.},
  language  = {en}
}