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Schlagwörter:
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Zusammenfassung:
Ever since Darwin, biologists are intrigued about evolution and its underlying mechanisms. In animals, neurobiological traits are key features that shape evolutionary diversity and novelty. We use an interdisciplinary approach that integrates development, neurobiology, ecology and population genetics to unravel the mechanistic changes that give rise to novelty and change. For this, we established Pristionchus pacificus as model system and combine laboratory studies building on genetic, genomic and transgenic tools with fieldwork. P. pacificus lives in association with scarab beetles. One key feature of its life style is a mouth-form dimorphism that enables predatory feeding. The development of teeth-like denticles of two different forms represents an example of developmental plasticity and we test the hypothesis that developmental plasticity is a facilitator of phenotypic diversification and the evolution of novelty. I will describe the molecular mechanisms underlying feeding plasticity and will show how the genetic machinery and the environment interact to specify this phenotypically plastic trait. Studying different Pristionchus species and a diversity of P. pacificus wild isolates, we identified the first organismal self- recognition system in nematodes1. I will summarize our subsequent genetic studies that identified the peptide SELF-1 to represent the major ligand in P. pacificus that prevents cannibalism in this system. In the second part of my talk, I will describe our studies that investigate the neurobiology of predation and self-recognition1. Building on nervous system reconstruction in P. pacificus, we have shown that predatory feeding behavior can be induced by serotonin treatment. CRISPR/Cas9 induced mutants in serotonin biosynthesis genes and genetic ablation studies indicate the exact role of serotonin and serotonergic neurons and identify a novel role of serotonin in in nervous system function.
