TY  - JOUR
A1  - Schäbler, Stefan
A1  - Amatobi, Kelechi M.
A1  - Horn, Melanie
A1  - Rieger, Dirk
A1  - Helfrich‑Förster, Charlotte
A1  - Mueller, Martin J.
A1  - Wegener, Christian
A1  - Fekete, Agnes
T1  - Loss of function in the Drosophila clock gene period results in altered intermediary lipid metabolism and increased susceptibility to starvation
JF  - Cellular and Molecular Life Sciences
N2  - The fruit fly Drosophila is a prime model in circadian research, but still little is known about its circadian regulation of metabolism. Daily rhythmicity in levels of several metabolites has been found, but knowledge about hydrophobic metabolites is limited. We here compared metabolite levels including lipids between period\(^{01}\) (per\(^{01}\)) clock mutants and Canton-S wildtype  (WT\(_{CS}\)) flies in an isogenic and non-isogenic background using LC–MS. In the non-isogenic background, metabo-lites with differing levels comprised essential amino acids, kynurenines, pterinates, glycero(phospho)lipids, and fatty acid esters. Notably, detectable diacylglycerols (DAG) and acylcarnitines (AC), involved in lipid metabolism, showed lower levels in per\(^{01}\) mutants. Most of these differences disappeared in the isogenic background, yet the level differences for AC as well as DAG were consistent for fly bodies. AC levels were dependent on the time of day in WTCS in phase with food consumption under LD conditions, while DAGs showed weak daily oscillations. Two short-chain ACs continued to cycle even in constant darkness. per\(^{01}\) mutants in LD showed no or very weak diel AC oscillations out of phase with feeding activity. The low levels of DAGs and ACs in per\(^{01}\) did not correlate with lower total food consumption, body mass or weight. Clock mutant flies showed higher sensitivity to starvation independent of their background-dependent activity level. Our results suggest that neither feeding, energy storage nor mobilisation is significantly affected in per\(^{01}\) mutants, but point towards impaired mitochondrial activity, supported by upregulation of the mitochondrial stress marker 4EBP in the clock mutants
KW  - circadian rhythms
KW  - metabolomics
KW  - mitochondrial activity
KW  - tryptophan
KW  - acylcarnitine
KW  - feeding
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232432
SN  - 1420-682X
VL  - 77
ER  - 
TY  - JOUR
A1  - Chen, Jiangtian
A1  - Reiher, Wencke
A1  - Hermann-Luibl, Christiane
A1  - Sellami, Azza
A1  - Cognigni, Paola
A1  - Kondo, Shu
A1  - Helfrich-Förster, Charlotte
A1  - Veenstra, Jan A.
A1  - Wegener, Christian
T1  - Allatostatin A Signalling in Drosophila Regulates Feeding and Sleep and Is Modulated by PDF
JF  - PLoS Genetics
N2  - Feeding and sleep are fundamental behaviours with significant interconnections and cross-modulations. The circadian system and peptidergic signals are important components of this modulation, but still little is known about the mechanisms and networks by which they interact to regulate feeding and sleep. We show that specific thermogenetic activation of peptidergic Allatostatin A (AstA)-expressing PLP neurons and enteroendocrine cells reduces feeding and promotes sleep in the fruit fly Drosophila. The effects of AstA cell activation are mediated by AstA peptides with receptors homolog to galanin receptors subserving similar and apparently conserved functions in vertebrates. We further identify the PLP neurons as a downstream target of the neuropeptide pigment-dispersing factor (PDF), an output factor of the circadian clock. PLP neurons are contacted by PDF-expressing clock neurons, and express a functional PDF receptor demonstrated by cAMP imaging. Silencing of AstA signalling and continuous input to AstA cells by tethered PDF changes the sleep/activity ratio in opposite directions but does not affect rhythmicity. Taken together, our results suggest that pleiotropic AstA signalling by a distinct neuronal and enteroendocrine AstA cell subset adapts the fly to a digestive energy-saving state which can be modulated by PDF.
KW  - neurons
KW  - neuroimaging
KW  - circadian rhythms
KW  - food consumption
KW  - sleep
KW  - biological locomotion
KW  - Drosophila melanogaster
KW  - signal peptides
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-178170
VL  - 12
IS  - 9
ER  -