The neuropeptide pigment-dispersing factor adjusts period and phase of Drosophila's clock.
The neuropeptide pigment-dispersing factor (PDF) is a key transmitter in the circadian clock of Drosophila melanogaster. PDF is necessary for robust activity rhythms and is thought to couple the circadian oscillations of the clock neurons. However, little is known about the action of PDF on individual clock neurons. Here, we combined the period-luciferase reporter system with immunolabeling of clock proteins in wild-type and Pdf(01) mutants to dissect the effects of PDF on specific subgroups of clock neurons. Additionally, PDF levels were elevated to higher than normal levels using specific neural mutants, and a correlation analysis of locomotor activity and clock protein staining served to determine the periods of specific clock cells. We found that PDF has multiple effects on the clock neurons: In some groups of clock neurons, PDF was required for maintaining the oscillations of individual cells, and in others, PDF was required for synchronous cycling of the individual members. Other clock neurons cycled with high amplitude in absence of PDF, but PDF affected their intrinsic clock speed. Sometimes PDF shortened and sometimes PDF lengthened period. Our observations indicate that PDF is crucial for adjusting cycling amplitude, period, and phase of the different players in the circadian clock. Under natural conditions PDF may be required for adapting Drosophila's clock to varying photoperiods. Indeed, we show here that Pdf(01) mutants are not able to adapt their activity to long photoperiods in a wild-type manner.
Yoshii
Taishi
T
Institute of Zoology, University of Regensburg, 93040 Regensburg, Germany.
Wülbeck
Corinna
C
Sehadova
Hana
H
Veleri
Shobi
S
Bichler
Dominik
D
Stanewsky
Ralf
R
Helfrich-Förster
Charlotte
C
D000222:Adaptation, Physiological / Q000235:genetics; D000704:Analysis of Variance; D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000166:cytology; D002940:Circadian Rhythm / Q000235:genetics*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D019476:Insect Proteins / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D056950:Period Circadian Proteins; D013997:Time Factors
D029721:Drosophila Proteins; D019476:Insect Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; C113883:pdf protein, Drosophila; C096445:tim protein, Drosophila; D008156:Luciferases