Transcriptomic response of Pristionchus pacificus to high nutritional conditions

Developmental plasticity, the ability of organisms to alter their phenotype in response to environmental variation, has been subject to intense studies in the last decade. The self- fertilizing nematode Pristionchus pacificus has been developed as one of the prime models of plasticity research due to its mouth-form polyphenism resulting in alternative feeding strategies with a facultative predatory and a non-predatory mouth form. Many studies linked molecular aspect of the regulation of mouth-form polyphenism with investigations of the evolutionary and ecological significance of plasticity. Also, several environmental factors influencing P. pacificus feeding structure expression were identified including temperature, culture condition and population density. However, the influence of the nutritional status has never been properly investigated although nutritional plasticity is well described in honeybees and other hymenopterans to control caste determination during development. Here, we study the influence of nutrition on mouth-form plasticity in P. pacificus through experiments with monosaccharide and fatty acid supplementation. We show that in particular glucose supplementation renders worms non-predatory. Subsequent transcriptomic and mutant analyses indicate associated molecular mechanisms. The analysis of fitness consequences through fecundity counts suggests that glucose supplementation-induced non-predatory animals have an advantage over predatory animals grown under the same condition.