Measuring C. elegans food intake in liquid culture

Author(s):  
Rafael Gomez-Amaro ◽  
Rafael Gomez-Amaro ◽  
Michael Petrascheck
Keyword(s):  
protocols.io ◽  
2019 ◽  
Author(s):  
Cristian Riccio ◽  
Asia Kosalka ◽  
WormBook not provided
Keyword(s):  

2021 ◽  
Vol 567 ◽  
pp. 29-34
Author(s):  
Xin Wang ◽  
Chunlong Zhang ◽  
Qirui Chen ◽  
Zhaowu Ma ◽  
Hui Liu ◽  
...  
Keyword(s):  

2019 ◽  
Author(s):  
Siyu Serena Ding ◽  
Karen S. Sarkisyan ◽  
Andre E. X. Brown

ABSTRACTFor most animals, feeding includes two behaviours: foraging to find a food patch and food intake once a patch is found. The nematode Caenorhabditis elegans is a useful model for studying the genetics of both behaviours. However, most methods of measuring feeding in worms quantify either foraging behaviour or food intake but not both. Imaging the depletion of fluorescently labelled bacteria provides information on both the distribution and amount of consumption, but even after patch exhaustion a prominent background signal remains, which complicates quantification. Here, we used a bioluminescent Escherichia coli strain to quantify C. elegans feeding. With light emission tightly coupled to active metabolism, only living bacteria are capable of bioluminescence so the signal is lost upon ingestion. We quantified the loss of bioluminescence using N2 reference worms and eat-2 mutants, and found a nearly 100-fold increase in signal-to-background ratio and lower background compared to loss of fluorescence. We also quantified feeding using aggregating npr-1 mutant worms. We found that groups of npr-1 mutants first clear bacteria from each other before foraging collectively for more food; similarly, during high density swarming, only worms at the migrating front are in contact with bacteria. These results demonstrate the usefulness of bioluminescent bacteria for quantifying feeding and suggest a hygiene hypothesis for the function of C. elegans aggregation and swarming.


2017 ◽  
Author(s):  
Robert Sobkowiak ◽  
Piotr Kaczmarek ◽  
Mateusz Kowalski ◽  
Rafał Kabaciński ◽  
Andrzej Lesicki

AbstractNicotine decreases food intake, and smokers often report that they smoke to control their weight. To see whether similar phenomena could be observed in the model organism Caenorhabditis elegans, we challenged drug-naϊve nematodes with a chronic low (0.01 mM) and high (1 mM) nicotine concentration for 55 h (from hatching to adulthood). After that, we recorded changes in their behavior in a nicotine gradient, where they could choose a desired nicotine concentration. By using a combination of behavioral and morphometric methods, we found that both nicotine and food modulate worm behavior. In the presence of food the nematodes adapted to the low nicotine concentration, when placed in the gradient, chose a similar nicotine concentration like C. elegans adapted to the high nicotine concentration. However, in the absence of food, the nematodes adapted to the low nicotine concentration, when placed in the gradient of this alkaloid, chose a similar nicotine concentration like naive worms. The nematodes growing up in the presence of high concentrations of nicotine had a statistically smaller body size, compared to the control condition, and the presence of food did not cause any enhanced slowing movement. These results provide a platform for more detailed molecular and cellular studies of nicotine addiction and food intake in this model organism.


eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yanan Sun ◽  
Meijiao Li ◽  
Dongfeng Zhao ◽  
Xin Li ◽  
Chonglin Yang ◽  
...  

Lysosomes play important roles in cellular degradation to maintain cell homeostasis. In order to understand whether and how lysosomes alter with age and contribute to lifespan regulation, we characterized multiple properties of lysosomes during the aging process in C. elegans. We uncovered age-dependent alterations in lysosomal morphology, motility, acidity and degradation activity, all of which indicate a decline in lysosome function with age. The age-associated lysosomal changes are suppressed in the long-lived mutants daf-2, eat-2 and isp-1, which extend lifespan by inhibiting insulin/IGF-1 signaling, reducing food intake and impairing mitochondrial function, respectively. We found that 43 lysosome genes exhibit reduced expression with age, including genes encoding subunits of the proton pump V-ATPase and cathepsin proteases. The expression of lysosome genes is upregulated in the long-lived mutants, and this upregulation requires the functions of DAF-16/FOXO and SKN-1/NRF2 transcription factors. Impairing lysosome function affects clearance of aggregate-prone proteins and disrupts lifespan extension in daf-2, eat-2 and isp-1 worms. Our data indicate that lysosome function is modulated by multiple longevity pathways and is important for lifespan extension.


2021 ◽  
Author(s):  
Tatiana V Villalobos ◽  
Bhaswati Ghosh ◽  
Sanaa Alam ◽  
Tyler J Butsch ◽  
Brennan M Mercola ◽  
...  

Dietary restriction promotes longevity via autophagy activation. However, changes to lysosomes underlying this effect remain unclear. Using the nematode Caenorhabditis elegans, we show that induction of autophagic tubular lysosomes, which occurs upon dietary restriction or mTOR inhibition, is a critical event linking reduced food intake to lifespan extension. We find that starvation induces tubular lysosomes not only in affected individuals but also in well-fed descendants, and the presence of gut tubular lysosomes in well-fed progeny is predictive of enhanced lifespan. Furthermore, we demonstrate that expression of Drosophila SVIP, a tubular-lysosome activator in flies, artificially induces tubular lysosomes in well-fed worms and improves C. elegans health in old age. These findings identify tubular lysosomes as a new class of lysosomes that couples starvation to healthy aging.


Genetics ◽  
2020 ◽  
Vol 214 (3) ◽  
pp. 577-587 ◽  
Author(s):  
Siyu Serena Ding ◽  
Maksym Romenskyy ◽  
Karen S. Sarkisyan ◽  
Andre E. X. Brown

For most animals, feeding includes two behaviors: foraging to find a food patch and food intake once a patch is found. The nematode Caenorhabditis elegans is a useful model for studying the genetics of both behaviors. However, most methods of measuring feeding in worms quantify either foraging behavior or food intake, but not both. Imaging the depletion of fluorescently labeled bacteria provides information on both the distribution and amount of consumption, but even after patch exhaustion a prominent background signal remains, which complicates quantification. Here, we used a bioluminescent Escherichia coli strain to quantify C. elegans feeding. With light emission tightly coupled to active metabolism, only living bacteria are capable of bioluminescence, so the signal is lost upon ingestion. We quantified the loss of bioluminescence using N2 reference worms and eat-2 mutants, and found a nearly 100-fold increase in signal-to-background ratio and lower background compared to loss of fluorescence. We also quantified feeding using aggregating npr-1 mutant worms. We found that groups of npr-1 mutants first clear bacteria from within the cluster before foraging collectively for more food; similarly, during large population swarming, only worms at the migrating front are in contact with bacteria. These results demonstrate the usefulness of bioluminescent bacteria for quantifying feeding and generating insights into the spatial pattern of food consumption.


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