title: Identification and characterization of circadian clock genes in the pea aphid Acyrthosiphon pisum.
abstract: The molecular basis of circadian clocks is highly evolutionarily conserved and has been best characterized in Drosophila and mouse. Analysis of the Acyrthosiphon pisum genome revealed the presence of orthologs of the following genes constituting the core of the circadian clock in Drosophila: period (per), timeless (tim), Clock, cycle, vrille, and Pdp1. However, the presence in A. pisum of orthologs of a mammal-type in addition to a Drosophila-type cryptochrome places the putative aphid clockwork closer to the ancestral insect system than to the Drosophila one. Most notably, five of these putative aphid core clock genes are highly divergent and exhibit accelerated rates of change (especially per and tim orthologs) suggesting that the aphid circadian clock has evolved to adapt to (unknown) aphid-specific needs. Additionally, with the exception of jetlag (absent in the aphid) other genes included in the Drosophila circadian clock repertoire were found to be conserved in A. pisum. Expression analysis revealed circadian rhythmicity for some core genes as well as a significant effect of photoperiod in the amplitude of oscillations.
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Cortés
authors.forename: B
authors.initials: B
authors.lastname: Ortiz-Rivas
authors.forename: D
authors.initials: D
authors.lastname: Martínez-Torres
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000235:genetics* / Q000502:physiology; D056926:CLOCK Proteins / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology; D004330:Drosophila / Q000235:genetics / Q000502:physiology; D019143:Evolution, Molecular; D017344:Genes, Insect; D049750:Genome, Insect; D019476:Insect Proteins / Q000235:genetics; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000469:parasitology; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D019476:Insect Proteins; D056926:CLOCK Proteins