The role of gene regulation in plasticity of behaviour and longevity: Ants – a success model of evolution

Abstract

Gene regulation plays a crucial role in evolutionary adaptation processes. Epigenetic regulators not only control the development of multicellular organisms, but also allow them to express different traits or phenotypes in response to environmental factors. Social insects, especially ants, could serve as a model for this phenotypic plasticity. For example, while queens and workers usually do not differ in genotype, they vary in gene expression, which leads to different morphology, physiology, behaviour, and lifespan over the course of their development. Gene regulation, i. e. the switching on and off of genes, has an important significance not only for caste differentiation, but also in the diverse division of labour in ant colonies. Ants are social insects in whose colonies the queen and workers divide up various tasks such as reproduction, brood care, nest building, and foraging. Histone modifcations, DNA methylation, and non-coding RNAs are important regulators of gene expression. The activity of candidate genes, such as the brood care gene vitellogenin-like A or genes for odorant receptors, control the behavioural specialization of workers. Their activity can be altered by RNAi and thus their function in regulating the division of labour can be experimentally tested. Parasites can also infuence gene expression and the phenotype of ants. For example, the infection by a tapeworm leads to life extension in a native ant species. The larva of this tapeworm – the manipulative functions of which are currently being explored – releases proteins into its ant host. The research work described here takes place as part of the interdisciplinary DFG Research Training Group 2526 GenEvo, which investigates the role of gene regulation in evolution and the evolution of regulatory processes themselves.