Greene Joshua S, Brown Maximillian, Dobosiewicz May, Ishida Itzel G, Macosko Evan Z, Zhang Xinxing, Butcher Rebecca A, Cline Devin J, McGrath Patrick T, Bargmann Cornelia I
Howard Hughes Medical Institute, Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, New York 10065, USA.
Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA.
Nature. 2016 Nov 10;539(7628):254-258. doi: 10.1038/nature19848. Epub 2016 Oct 31.
The optimal foraging strategy in a given environment depends on the number of competing individuals and their behavioural strategies. Little is known about the genes and neural circuits that integrate social information into foraging decisions. Here we show that ascaroside pheromones, small glycolipids that signal population density, suppress exploratory foraging in Caenorhabditis elegans, and that heritable variation in this behaviour generates alternative foraging strategies. We find that natural C. elegans isolates differ in their sensitivity to the potent ascaroside icas#9 (IC-asc-C5). A quantitative trait locus (QTL) regulating icas#9 sensitivity includes srx-43, a G-protein-coupled icas#9 receptor that acts in the ASI class of sensory neurons to suppress exploration. Two ancient haplotypes associated with this QTL confer competitive growth advantages that depend on ascaroside secretion, its detection by srx-43 and the distribution of food. These results suggest that balancing selection at the srx-43 locus generates alternative density-dependent behaviours, fulfilling a prediction of foraging game theory.
在特定环境中，最优觅食策略取决于竞争个体的数量及其行为策略。关于将社会信息整合到觅食决策中的基因和神经回路，我们所知甚少。在这里，我们表明，ascaroside信息素（一种能表明种群密度的小糖脂）会抑制秀丽隐杆线虫的探索性觅食行为，并且这种行为的遗传变异会产生不同的觅食策略。我们发现，天然的秀丽隐杆线虫分离株对强效ascaroside icas#9（IC-asc-C5）的敏感性存在差异。一个调节icas#9敏感性的数量性状位点（QTL）包含srx-43，它是一种G蛋白偶联的icas#9受体，在ASI类感觉神经元中发挥作用以抑制探索行为。与该QTL相关的两种古老单倍型赋予了竞争生长优势，这种优势取决于ascaroside的分泌、srx-43对其的检测以及食物的分布。这些结果表明，srx-43位点的平衡选择产生了不同的密度依赖性行为，这符合觅食博弈论的一个预测。
