scholarly journals Most sleep does not serve a vital function: Evidence from Drosophila melanogaster

2019 ◽  
Vol 5 (2) ◽  
pp. eaau9253 ◽  
Author(s):  
Quentin Geissmann ◽  
Esteban J. Beckwith ◽  
Giorgio F. Gilestro

Sleep appears to be a universally conserved phenomenon among the animal kingdom, but whether this notable evolutionary conservation underlies a basic vital function is still an open question. Using a machine learning–based video-tracking technology, we conducted a detailed high-throughput analysis of sleep in the fruit fly Drosophila melanogaster, coupled with a lifelong chronic and specific sleep restriction. Our results show that some wild-type flies are virtually sleepless in baseline conditions and that complete, forced sleep restriction is not necessarily a lethal treatment in wild-type D. melanogaster. We also show that circadian drive, and not homeostatic regulation, is the main contributor to sleep pressure in flies. These results offer a new perspective on the biological role of sleep in Drosophila and, potentially, in other species.

2018 ◽  
Author(s):  
Quentin Geissmann ◽  
Esteban J. Beckwith ◽  
Giorgio F. Gilestro

AbstractSleep appears to be a universally conserved phenomenon among the animal kingdom but whether this striking evolutionary conservation underlies a basic vital function is still an open question. Using novel technologies, we conducted an unprecedentedly detailed high-throughput analysis of sleep in the fruit fly Drosophila melanogaster, coupled with a life-long chronic and specific sleep restriction. Our results show that some wild-type flies are virtually sleepless in baseline conditions and that complete, forced sleep restriction is not necessarily a lethal treatment in wild-type Drosophila melanogaster. We also show that circadian drive, and not homeostatic regulation, is the main contributor to sleep pressure in flies. We propose a three-partite model framework of sleep function, according to which, total sleep accounts for three components: a vital component, a useful component, and an accessory component.


2021 ◽  
pp. 074873042199811
Author(s):  
Franziska Ruf ◽  
Oliver Mitesser ◽  
Simon Tii Mungwa ◽  
Melanie Horn ◽  
Dirk Rieger ◽  
...  

The adaptive significance of adjusting behavioral activities to the right time of the day seems obvious. Laboratory studies implicated an important role of circadian clocks in behavioral timing and rhythmicity. Yet, recent studies on clock-mutant animals questioned this importance under more naturalistic settings, as various clock mutants showed nearly normal diel activity rhythms under seminatural zeitgeber conditions. We here report evidence that proper timing of eclosion, a vital behavior of the fruit fly Drosophila melanogaster, requires a functional molecular clock under quasi-natural conditions. In contrast to wild-type flies, period01 mutants with a defective molecular clock showed impaired rhythmicity and gating in a temperate environment even in the presence of a full complement of abiotic zeitgebers. Although period01 mutants still eclosed during a certain time window during the day, this time window was much broader and loosely defined, and rhythmicity was lower or lost as classified by various statistical measures. Moreover, peak eclosion time became more susceptible to variable day-to-day changes of light. In contrast, flies with impaired peptidergic interclock signaling ( Pdf01 and han5304 PDF receptor mutants) eclosed mostly rhythmically with normal gate sizes, similar to wild-type controls. Our results suggest that the presence of natural zeitgebers is not sufficient, and a functional molecular clock is required to induce stable temporal eclosion patterns in flies under temperate conditions with considerable day-to-day variation in light intensity and temperature. Temperate zeitgebers are, however, sufficient to functionally rescue a loss of PDF-mediated clock-internal and -output signaling


Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 1063-1075
Author(s):  
M.C. Lienhard ◽  
R.F. Stocker

The development of the sensory neuron pattern in the antennal disc of Drosophila melanogaster was studied with a neuron-specific monoclonal antibody (22C10). In the wild type, the earliest neurons become visible 3 h after pupariation, much later than in other imaginal discs. They lie in the center of the disc and correspond to the neurons of the adult aristal sensillum. Their axons join the larval antennal nerve and seem to establish the first connection towards the brain. Later on, three clusters of neurons appear in the periphery of the disc. Two of them most likely give rise to the Johnston's organ in the second antennal segment. Neurons of the olfactory third antennal segment are formed only after eversion of the antennal disc (clusters t1-t3). The adult pattern of antennal neurons is established at about 27% of metamorphosis. In the mutant lozenge3 (lz3), which lacks basiconic antennal sensilla, cluster t3 fails to develop. This indicates that, in the wild type, a homogeneous group of basiconic sensilla is formed by cluster t3. The possible role of the lozenge gene in sensillar determination is discussed. The homeotic mutant spineless-aristapedia (ssa) transforms the arista into a leg-like tarsus. Unlike leg discs, neurons are missing in the larval antennal disc of ssa. However, the first neurons differentiate earlier than in normal antennal discs. Despite these changes, the pattern of afferents in the ectopic tarsus appears leg specific, whereas in the non-transformed antennal segments a normal antennal pattern is formed. This suggests that neither larval leg neurons nor early aristal neurons are essential for the outgrowth of subsequent afferents.


The occurrence of mutants of Drosophila melanogaster distinguished by the absence or structural modification of the antennae provides a means of assessing the role of the antennae with respect to the reception of various classes of stimuli. Antennaless ( A 0 ) phenotypes of antennaless stock fail to respond to those chemical stimuli which lead the fly to its food. Their temperature reactions are normal, and their humidity responses are opposite to those of somatically wild-type flies of the same stock or of wild-type controls. Aristapedia ( ss a ), which have leg-like antennae equipped with surface pegs and cones of supposed sensory function present in the normal antenna but absent in the normal leg, respond to chemical stimuli and humidity differences. As compared with that of normal flies, the olfactory response of aristapedia ( ss a ) is somewhat less intense, the humidity reaction being somewhat stronger. These mutants do not give the characteristic responses evoked by thermal stimuli both in normal flies and antennaless phenotypes. The outstanding histological differences between the structure of the antenna of aristapedia and that of wild-type flies is the absence of the pit organ. It thus seems that the pit organ is not essential to the olfactory response and plays no essential part in the humidity response. Since antennaless ( A 0 ) responds normally to thermal stimuli, none of the putative sense organs of the antennae are essential to the recognition of temperature differences, and since aristapedia ( ss a ) responds more weakly to chemical stimuli than do normal flies, the pit organs may well be long-distance chemoreceptors. What is more certain is that either the peg-like organs or the cones on the surface of the distal joint of the antennae or both are chemoreceptors. The same remark is equally applicable to the perception of humidity differences. Experiments here recorded do not justify the identification of the function of one or other type of sensilla with one or the other type of receptivity. While it is unjustifiable to exclude the possibility that short-distance chemical stimuli play a part in the attraction of flies of opposite sex, it appears that the main role of chemoreceptivity in relation to the mating behaviour of D. melanogaster is to ensure the aggregation of flies of both sexes in situations where food is available and sexual congress can be evoked by other forms of stimulation.


2001 ◽  
Vol 183 (4) ◽  
pp. 1466-1471 ◽  
Author(s):  
David A. D'Argenio ◽  
Larry A. Gallagher ◽  
Celeste A. Berg ◽  
Colin Manoil

ABSTRACT Using the fruit fly Drosophila melanogaster as model host, we have identified mutants of the bacterium Pseudomonas aeruginosa with reduced virulence. Strikingly, all strains strongly impaired in fly killing also lacked twitching motility; most such strains had a mutation in pilGHIJKL chpABCDE, a gene cluster known to be required for twitching motility and potentially encoding a signal transduction system. The pil chp genes appear to control the expression of additional virulence factors, however, since the wild-type fly-killing phenotype of a subset of mutants isolated on the basis of their compact colony morphology indicated that twitching motility itself was not required for full virulence in the fly.


Author(s):  
Abeer Mohbeddin ◽  
Nawar Haj Ahmed ◽  
Layla Kamareddine

Apart from its traditional role in disease control, recent body of evidence has implicated a role of the immune system in regulating metabolic homeostasis. Owing to the importance of this “immune-metabolic alignment” in dictating a state of health or disease, a proper mechanistic understanding of this alignment is crucial in opening up for promising therapeutic approaches against a broad range of chronic, metabolic, and inflammatory disorders like obesity, diabetes, and inflammatory bowel syndrome. In this project, we addressed the role of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) innate immune pathway in regulating different metabolic parameters using the Drosophila melanogaster (DM) fruit fly model organism. Mutant JAK/STAT pathway flies with a systemic knockdown of either Domeless (Dome) [domeG0282], the receptor that activates JAK/STAT signaling, or the signal-transducer and activator of transcription protein at 92E (Stat92E) [stat92EEY10528], were used. The results of the study revealed that blocking JAK/STAT signaling alters the metabolic profile of mutant flies. Both domeG0282 and stat92EEY10528 mutants had an increase in body weight, lipid deprivation from their fat body (lipid storage organ in flies), irregular accumulation of lipid droplets in the gut, systemic elevation of glucose and triglyceride levels, and differential down-regulation in the relative gene expression of different peptide hormones (Tachykinin, Allatostatin C, and Diuretic hormone 31) known to regulate metabolic homeostasis in flies. Because the JAK/STAT pathway is evolutionary conserved between invertebrates and vertebrates, our potential findings in the fruit fly serves as a platform for further immune-metabolic translational studies in more complex mammalian systems including humans.


2021 ◽  
Author(s):  
Vladislav Mokeev ◽  
Yiwen Wang ◽  
Nicole Gehring ◽  
Bernard Moussian

Abstract Objectives As in most organisms, the surface of the fruit fly Drosophila melanogaster is associated with bacteria. In order to study the genetic parameters of this association, we developed a simple protocol for surface bacteria isolation and quantification. Results On wild-type flies maintained in the laboratory, we identified two persistently culturable species as Lactobacillus plantarum and Acetobacter pomorum by 16S rDNA sequencing. For quantification, we showered single flies for DNA extraction avoiding the rectum to prevent contamination from the gut. Using specific primers for quantitative PCR analyses, we determined the relative abundance of these two species in surface wash samples. Repeatedly, we found 20% more L. plantarum than A. pomorum . To tentatively study the importance of the cuticle for the interaction of the surface with these bacteria, applying Crispr/Cas9 gene editing in the initial wild-type flies, we generated flies mutant for the ebony gene needed for cuticle melanisation and determined the L. plantarum to A. pomorum ratio on these flies. We found that the relative abundance of L. plantarum increased substantially on ebony flies. We conclude that the cuticle chemistry is crucial for surface bacteria composition. This finding may inspire future studies on cuticle-microbiome interactions.


2010 ◽  
Vol 8 (3) ◽  
pp. 67-80 ◽  
Author(s):  
Aleksey A Moskalev ◽  
Olga A Malysheva

It was investigated the role of stress-response genes (dFOXO, dSir2, Hsp70) in regulation of life span of Drosophila in response to light regime alteration. It was revealed the FOXO-dependant mechanism of lifespan increasing at darkness conditions. The distance of lifespan of FOXO homozygous mutants at different light conditions were absent 3 times from 4 times. It was shown, that homozygotes with deletion of dSir2 have more significant difference between lifespan at standard light and darkness conditions with comparing to wild type and heterozygous strain. The same tendency was also detected the in the strains with Hsp70 deletions. It was produced the evidences of two mechanisms of light regime influence on lifespan: metabolism intensification at light conditions and neuroendocrine-determinated lifespan increasing at darkness conditions.


2020 ◽  
Vol 21 (6) ◽  
pp. 2002 ◽  
Author(s):  
Darcy C. Engelhart ◽  
Priti Azad ◽  
Suwayda Ali ◽  
Jeffry C. Granados ◽  
Gabriel G. Haddad ◽  
...  

The SLC22 family of transporters is widely expressed, evolutionarily conserved, and plays a major role in regulating homeostasis by transporting small organic molecules such as metabolites, signaling molecules, and antioxidants. Analysis of transporters in fruit flies provides a simple yet orthologous platform to study the endogenous function of drug transporters in vivo. Evolutionary analysis of Drosophila melanogaster putative SLC22 orthologs reveals that, while many of the 25 SLC22 fruit fly orthologs do not fall within previously established SLC22 subclades, at least four members appear orthologous to mammalian SLC22 members (SLC22A16:CG6356, SLC22A15:CG7458, CG7442 and SLC22A18:CG3168). We functionally evaluated the role of SLC22 transporters in Drosophila melanogaster by knocking down 14 of these genes. Three putative SLC22 ortholog knockdowns—CG3168, CG6356, and CG7442/SLC22A—did not undergo eclosion and were lethal at the pupa stage, indicating the developmental importance of these genes. Additionally, knocking down four SLC22 members increased resistance to oxidative stress via paraquat testing (CG4630: p < 0.05, CG6006: p < 0.05, CG6126: p < 0.01 and CG16727: p < 0.05). Consistent with recent evidence that SLC22 is central to a Remote Sensing and Signaling Network (RSSN) involved in signaling and metabolism, these phenotypes support a key role for SLC22 in handling reactive oxygen species.


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