Multiple amidated neuropeptides are required for normal circadian locomotor rhythms in Drosophila.
In Drosophila, the amidated neuropeptide pigment dispersing factor (PDF) is expressed by the ventral subset of lateral pacemaker neurons and is required for circadian locomotor rhythms. Residual rhythmicity in pdf mutants likely reflects the activity of other neurotransmitters. We asked whether other neuropeptides contribute to such auxiliary mechanisms. We used the gal4/UAS system to create mosaics for the neuropeptide amidating enzyme PHM; amidation is a highly specific and widespread modification of secretory peptides in Drosophila. Three different gal4 drivers restricted PHM expression to different numbers of peptidergic neurons. These mosaics displayed aberrant locomotor rhythms to degrees that paralleled the apparent complexity of the spatial patterns. Certain PHM mosaics were less rhythmic than pdf mutants and as severe as per mutants. Additional gal4 elements were added to the weakly rhythmic PHM mosaics. Although adding pdf-gal4 provided only partial improvement, adding the widely expressed tim-gal4 largely restored rhythmicity. These results indicate that, in Drosophila, peptide amidation is required for neuropeptide regulation of behavior. They also support the hypothesis that multiple amidated neuropeptides, acting upstream, downstream, or in parallel to PDF, help organize daily locomotor rhythms.
Taghert
P H
PH
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. taghertp@thalamus.wustl.edu
Hewes
R S
RS
Park
J H
JH
O'Brien
M A
MA
Han
M
M
Peck
M E
ME
D000577:Amides / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D002490:Central Nervous System / Q000166:cytology / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D004268:DNA-Binding Proteins; D004330:Drosophila; D029721:Drosophila Proteins; D004742:Enhancer Elements, Genetic / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics; D005804:Genes, Lethal; D017930:Genes, Reporter; D008124:Locomotion / Q000502:physiology*; D008297:Male; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000235:genetics; D009030:Mosaicism / Q000235:genetics; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000235:genetics; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics
D000577:Amides; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D009097:Multienzyme Complexes; D009479:Neuropeptides; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C113883:pdf protein, Drosophila; D006899:Mixed Function Oxygenases; C035189:peptidylglycine monooxygenase