Ascarosides are small molecule pheromones in nematodes that regulate a number of behaviors like attraction, repulsion, aggregation with other worms and entry into dauer or environmental diapause. In a recent publication from the Sternberg lab in Current Biology (click here for a link to the article) ascarosides were analyzed by mass spectrometry across nematode species. The authors found that in general ascarosides are species specific and cluster not only by phylogeny, but also by environmental or life history niche. Below the figure from the paper illustrates the relationship of specific ascaroside presence and abundance with phylogeny, life history and mode of reproduction.
Interestingly, the authors also look at specific isolates of the “wild type” of the commonly used model organism, Caenorhabditis elegans and found differences within the same species. These differences however, are quite small when compared to the differences observed across species.