Convergent evolution of small molecule pheromones in pristionchus nematodes

Abstract

The small molecules that mediate chemical communication between nematodes—so-called “nematode-derived-modular-metabolites” (NDMMs)—are of major interest due to their ability to regulate development, behavior, and life-history. Pristionchus pacificus nematodes produce an impressive diversity of structurally complex NDMMs, some of which act as primer pheromones capable of triggering irreversible developmental switches. Many of these NDMMs have only ever been found in P. pacificus but no attempts had been made to study their evolution by profiling closely related species. This study was designed to bring a comparative perspective to the biochemical study of NDMMs via the systematic MS/MS and NMR-based analysis of exo-metabolomes from over 30 Pristionchus species. We identified 36 novel compounds and found evidence for the convergent evolution of complex NDMMs in separate branches of the Pristionchus phylogeny. Our results demonstrate that biochemical innovation is a recurrent process in Pristionchus nematodes, a pattern likely typical across the animal kingdom.