title: A recessive mutant of Drosophila Clock reveals a role in circadian rhythm amplitude.
abstract: The transcription factor Clock (Clk) plays a critical role in animal circadian rhythms. Genetic studies defining its function have relied on two dominant negative alleles, one in Drosophila and one in mice. Here we describe a novel recessive allele of Drosophila Clock, Clk(ar). Homozygous Clk(ar) flies are viable and behaviorally arrhythmic. The Clk(ar) phenotype is caused by a splice site mutation that severely disrupts splicing and reduces Clk activity. Despite the behavioral arrhythmicity, molecular oscillations are still detectable in Clk(ar) flies. Transcription analysis indicates potent effects of Clk(ar) on levels and amplitude of transcriptional oscillations. Taken together with other data, we propose that Clk makes a major contribution to the strength and amplitude of circadian rhythms.
authors.affiliation: Howard Hughes Medical Institute and Department of Biology, Brandeis University, Waltham, MA 02454, USA.
authors.forename: Ravi
authors.initials: R
authors.lastname: Allada
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kadener
authors.forename: Namrata
authors.initials: N
authors.lastname: Nandakumar
authors.forename: Michael
authors.initials: M
authors.lastname: Rosbash
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D001522:Behavior, Animal / Q000502:physiology; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers; D004330:Drosophila; D029721:Drosophila Proteins; D005808:Genes, Recessive; D009154:Mutation; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: C120526:Clk protein, Drosophila; D017931:DNA Primers; D029721:Drosophila Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D056926:CLOCK Proteins