title: Adaptation of Circadian Neuronal Network to Photoperiod in High-Latitude European Drosophilids.
abstract: The genus Drosophila contains over 2,000 species that, stemming from a common ancestor in the Old World Tropics, populate today very different environments [1, 2] (reviewed in [3]). We found significant differences in the activity pattern of Drosophila species belonging to the holarctic virilis group, i.e., D. ezoana and D. littoralis, collected in Northern Europe, compared to that of the cosmopolitan D. melanogaster, collected close to the equator. These behavioral differences might have been of adaptive significance for colonizing high-latitude habitats and hence adjust to long photoperiods. Most interestingly, the flies' locomotor activity correlates with the neurochemistry of their circadian clock network, which differs between low and high latitude for the expression pattern of the blue light photopigment cryptochrome (CRY) and the neuropeptide Pigment-dispersing factor (PDF) [4-6]. In D. melanogaster, CRY and PDF are known to modulate the timing of activity and to maintain robust rhythmicity under constant conditions [7-11]. We could partly simulate the rhythmic behavior of the high-latitude virilis group species by mimicking their CRY/PDF expression patterns in a laboratory strain of D. melanogaster. We therefore suggest that these alterations in the CRY/PDF clock neurochemistry might have allowed the virilis group species to colonize high-latitude environments.
authors.affiliation: Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Pamela
authors.initials: P
authors.lastname: Menegazzi
authors.affiliation: Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Dalla Benetta
authors.affiliation: Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Marta
authors.initials: M
authors.lastname: Beauchamp
authors.affiliation: Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schlichting
authors.affiliation: Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Ingolf
authors.initials: I
authors.lastname: Steffan-Dewenter
authors.affiliation: Neurobiology and Genetics, Theodor Boveri Institute, Biocentre, University of Würzburg, 97074 Würzburg, Germany. Electronic address: charlotte.foerster@biozentrum.uni-wuerzburg.de.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Helfrich-Förster
mesh_terms: D000818:Animals; D057906:Circadian Clocks / Q000235:genetics*; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005387:Finland; D008124:Locomotion; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D017440:Photoperiod; D013045:Species Specificity; D013636:Tanzania
chemical_list: D029721:Drosophila Proteins
keywords: Drosophila ezoana; Drosophila littoralis; Drosophila melanogaster; circadian rhythms; cryptochrome; low and high latitudes; pigment dispersing factor