Catecholamine receptor polymorphisms affect decision-making in C. elegans
Andres Bendesky, Makoto Tsunozaki, Matthew V. Rockman, Leonid Kruglyak & Cornelia I. Bargmann
Nature (2011) doi:10.1038/nature09821
Innate behaviours are flexible: they change rapidly in response to transient environmental conditions, and are modified slowly by changes in the genome. A classical flexible behaviour is the exploration–exploitation decision, which describes the time at which foraging animals choose to abandon a depleting food supply. We have used quantitative genetic analysis to examine the decision to leave a food patch in Caenorhabditis elegans. Here we show that patch-leaving is a multigenic trait regulated in part by naturally occurring non-coding polymorphisms in tyra-3 (tyramine receptor 3), which encodes a G-protein-coupled catecholamine receptor related to vertebrate adrenergic receptors. tyra-3 acts in sensory neurons that detect environmental cues, suggesting that the internal catecholamines detected by tyra-3 regulate responses to external conditions. These results indicate that genetic variation and environmental cues converge on common circuits to regulate behaviour, and suggest that catecholamines have an ancient role in regulating behavioural decisions.
The legends of the two movies used for the below displayed visual are:
Supplementary Movie 1 (8.5M)
This movie shows leaving assay showing six N2 adults, 20x actual speed. The border of the bacterial lawn is outlined for ease of visualization. Time stamp at upper left displays the actual time after placing the animals on the assay plate.
Supplementary Movie 2 (8.5M)
This movie shows leaving assay showing six HW adults, 20x actual speed. Four animals are on the lawn and two off the lawn at the beginning of the assay. The border of the bacterial lawn is outlined for ease of visualization. Time stamp at upper left displays the actual time after placing the animals on the assay plate.
A Z axis projection, where Z the time (2251 frames of the time-lapse movies), make a much easier to grasp illustration of the extent of traveling observed for the two strains: