Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2024.07.11.603021

Olfactory basis for essential amino acid perception during foraging in Caenorhabditis elegans

Siddiqui, R.·Mehta, N.·Ranjith, G.·Felix, M.-A.·Chen, C.·Singh, V.
View original source ↗Export metadata ↓

Abstract

Acquisition of essential nutrients through diet is crucial for the survival of animals. Dietary odors might enable animals to forage for nutrient-rich diets. We asked if Caenorhabditis elegans, a bacterivorous nematode, uses olfactory cues to forage for essential amino acid-rich (EAA) diets. Using the native microbiome of C. elegans, we show that worms rely on olfaction to select leucine (EAA)-enriched bacteria. Using gas chromatography, we find that leucine-enriched bacteria produce isoamyl alcohol (IAA) odor in the highest abundance. Prior adaptation of worms to IAA diminishes the diet preference of worms. Several wild isolates of C. elegans display robust responses to IAA emphasizing its ecological relevance. We find that foraging for a leucine-enriched diet is mediated via the AWC olfactory neurons. Finally, we identify SNIF-1 G protein-coupled receptor in AWC neurons as a receptor for IAA and a mediator of dietary decisions in worms. Our study identifies a receptor-ligand module underpinning foraging behavior in C. elegans.

Explore related subjects

animal behavior and cognitionPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Siddiqui, R., Mehta, N., Ranjith, G., Felix, M.-A., Chen, C., Singh, V.. 2024-07-12. Olfactory basis for essential amino acid perception during foraging in Caenorhabditis elegans. https://doi.org/10.1101/2024.07.11.603021

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Characterizing risky play-like behaviour in juvenile versus young adult rats

Play is an evolutionarily conserved behaviour that contributes to healthy behavioural and neural development. While animal play is traditionally categorized as locomotor, object, or social play, developmental research in children has highlighted the importance of risky play, defined as voluntary engagement with uncertainty and manageable physical risk. Whether similar forms of behaviour occur in non-human animals remains largely unexplored. The present study aimed to establish an ethological framework for identifying and quantifying risky play-like behaviour in rats. Juvenile and young adult male Lister Hooded rats were repeatedly exposed to a custom-designed environment containing elevated and unstable structures that provided opportunities for climbing, balancing, hanging, jumping and social interaction. Behaviour was quantified using two complementary ethograms: a location-based ethogram describing the animal's position within the apparatus and a risky event ethogram capturing selected behaviours associated with physical challenge. By comparing the behaviour of animals during the natural peak of play behaviour with animals beyond this developmental period, we aimed to evaluate whether engagement with elevated and unstable environments reflects play-related processes rather than environmental complexity alone. This study provides a behavioural framework for investigating risky play-like behaviour in rodents and establishes a foundation for future studies examining its developmental and neurobiological significance.

animal behavior and cognition↗
bioRxiv2026

Toward welfare indicators: leg condition and aversive stimuli modulate defensive behavior in Opilones

The history of invertebrate use in research and their growing use in managed settings highlight the need for validated behavioral indicators of welfare, yet these remain poorly understood across taxa. The arachnid group Opiliones (harvestmen or daddy long-legs) is an ideal group for identifying welfare indicators, given their well-characterized defensive behavior, including the common strategy of leg autotomy. The goal of this project was to identify candidate behavioral welfare indicators for Prionostemma sp. 1 in the Neotropical rainforest. We brought field-collected individuals with different leg conditions to the lab and briefly exposed them to an aversive stimulus (a gentle squeeze and release) paired with an assigned substrate (either rock or sand). A rewarding stimulus (food) was provided on the alternate substrate. We found no evidence of preference for roosting on the substrate associated with the rewarding stimulus, nor avoidance of the substrate associated with the aversive stimulus. Thus, evidence for associative learning was not supported. Additionally, substrate use did not differ based on leg condition (intact, missing 1-2 legs, or missing sensory legs). After an aversive stimulus, fleeing was consistently the most common response throughout 5 days. In contrast, the frequency of bobbing increased while the frequency of escaping decreased over trials. Individuals with all legs tended to escape more often than those missing legs, but neither the number nor the type of missing legs substantially improved predictions of behavioral responses. Overall, fleeing and bobbing may serve as behavioral indicators of negative welfare states, whereas the observed absence of exploratory tapping following the aversive stimulus suggests that this behavior may indicate neutral or positive welfare states. As one of the first investigations of welfare indicators in wild arachnids, this study provides novel insights into how defensive behaviors and physical condition may inform assessments of invertebrate welfare, laying the groundwork for future validation of behavioral indicators.

animal behavior and cognition↗
bioRxiv2026

Sensitive period for song learning outlasts parent-offspring cohesion in wild zebra finches

Communication is central to social behaviour, with vocalisations playing a crucial role in many species. In some species, vocalisations are learned, with songbirds being key to understanding vocal learning. The Australian zebra finch (Taeniopygia castanotis) is the most studied model organism for vocal learning. In captivity, juveniles are typically housed with their father, where males learn their father song and females develop a preference for that song. In nature, however, the social structure of zebra finches is more dynamic across space and time. To identify the natural social conditions during song learning, we followed zebra finch families across their early life in the wild using automated radio-tracking. The distance between juveniles and their parents increased post-fledging and became similar to the distance between juveniles and unrelated adults by the second half of the song learning period. These findings indicate a highly dynamic social environment during the song learning period and suggest that juvenile males could learn from many tutors and that females may develop broader song preferences. Thus, studies based on one-tutor paradigms should be interpreted carefully with respect to functional implications and highlight that future vocal learning studies could better reflect the social conditions under which song develops.

animal behavior and cognition↗