Genomic reaction norms: using integrative biology to understand molecular mechanisms of phenotypic plasticity


  • Nadia Aubin-Horth is an assistant professor at Université de Montréal. Members of her lab study the molecular and hormonal mechanisms that underlie inter-individual variation in social dominance, temperament and reproductive tactics in African cichlids and the threespine stickleback. They do so using a combination of behavioural biology, endocrinology, pharmacological and environmental perturbations, as well as functional genomics approaches. Suzy Renn is an assistant professor of Biology at Reed College. She aims to determine if similar behaviours result from conserved or converged processes of evolution in African Cichlid fishes. She does so by studying the molecular basis of species- and context-specific behaviours through the synergistic combination of functional genomics, behaviour, physiology and ecology.

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    Present address: Département de Biologie et Institut de biologie intégrative et des systēmes, Université Laval, Québec, Canada, G1V OA6

Nadia Aubin-Horth, Fax: 514 343 2293; E-mail:


Phenotypic plasticity is the development of different phenotypes from a single genotype, depending on the environment. Such plasticity is a pervasive feature of life, is observed for various traits and is often argued to be the result of natural selection. A thorough study of phenotypic plasticity should thus include an ecological and an evolutionary perspective. Recent advances in large-scale gene expression technology make it possible to also study plasticity from a molecular perspective, and the addition of these data will help answer long-standing questions about this widespread phenomenon. In this review, we present examples of integrative studies that illustrate the molecular and cellular mechanisms underlying plastic traits, and show how new techniques will grow in importance in the study of these plastic molecular processes. These techniques include: (i) heterologous hybridization to DNA microarrays; (ii) next generation sequencing technologies applied to transcriptomics; (iii) techniques for studying the function of noncoding small RNAs; and (iv) proteomic tools. We also present recent studies on genetic model systems that uncover how environmental cues triggering different plastic responses are sensed and integrated by the organism. Finally, we describe recent work on changes in gene expression in response to an environmental cue that persist after the cue is removed. Such long-term responses are made possible by epigenetic molecular mechanisms, including DNA methylation. The results of these current studies help us outline future avenues for the study of plasticity.