Circadian rhythms in Neurospora crassa: clock mutant effects in the absence of a frq-based oscillator.
In Neurospora, the circadian rhythm is expressed as rhythmic conidiation driven by a feedback loop involving the protein products of frq (frequency), wc-1 (white collar-1), and wc-2, known as the frq/wc (FWC) oscillator. Although strains carrying null mutations such as frq(10) or wc-2Delta lack a functional FWC oscillator and do not show a rhythm under most conditions, a rhythm can be observed in them by the addition of geraniol or farnesol to the media. Employing this altered media as an assay, the effect of other clock mutations in a frq(10)- or wc-2Delta-null background can be measured. It was found that the existing clock mutations fall into three classes: (1) those, such as prd-3 or prd-4 or frq(1), that showed no effect in a clock null background; (2) those, such as prd-1 or prd-2 or prd-6, that did have a measurable effect in the frq(10) background; and (3) those, such as the new mutation ult, that suppressed the frq(10) or wc-2Delta effect, i.e., geraniol/farnesol was not required for a visible rhythm. This classification suggests that some of the known clock mutations are part of a broader multioscillator system.
Lombardi
Laura
L
Division of Biological Sciences, University of California, San Diego, California 92093-0116, USA.
Schneider
Kevin
K
Tsukamoto
Michelle
M
Brody
Stuart
S
D000080462:Acyclic Monoterpenes; D001683:Biological Clocks / Q000235:genetics* / Q000502:physiology; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D003470:Culture Media; D003720:Densitometry; D005204:Farnesol; D005656:Fungal Proteins / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D009492:Neurospora crassa / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013729:Terpenes
D000080462:Acyclic Monoterpenes; D003470:Culture Media; C087405:FRQ protein, Neurospora crassa; D005656:Fungal Proteins; D013729:Terpenes; D005204:Farnesol; C007836:geraniol