Mission Statement

The long-term goal of the department is to understand the mechanisms underlying variation in adaptive traits. As a prerequisite, the genes that are used by wild plants and animals to create phenotypic diversity need to be defined. By integrating a mechanistic understanding of genetic networks with an understanding of the adaptive significance of trait variation, it should be possible to identify functionally divergent alleles in natural populations. This knowledge can be used to understand the genetic mechanisms underlying adaptive change, and to predict the performance of natural populations under changing environmental conditions.

Overview

The department focuses on two aspects of development: its mechanistic foundation, which is being studied in the reference organisms Arabidopsis thaliana and Drosophila melanogaster; and the genetic and genomic basis of naturally occurring variation, which is being studied in Arabidopsis as well as the guppy, Poecilia reticulata.

Multicellularity, and thus the necessity to build complex patterns from individual cells, evolved independently in animals and plants. Hence, a comparison of pattern formation in the two groups allows one to distinguish mechanisms and signalling processes that are in?dispensable for morphogenesis from those that can be substituted by new ones. Interactions in transcriptional and microRNA networks are examples of common mechanisms that are being studied, while the direct transfer of signalling molecules between cells is an example of a divergent mechanism unique to plants.

A largely plant-specific phenomenon is the tremendous plasticity of post-embryonic development in genetically identical individuals. Plants therefore offer an exceptional opportunity to understand the interplay between environmental signals and hard-wired developmental programs. The model being used in the department is the control of flowering by factors such as day length and ambient temperature. Developmental plasticity is also apparent between genetically distinct individuals, both within species and between closely related ones. Because much is known about the molecular basis of flowering control, the department studies the onset of reproductive development as a model adaptive trait in Arabidopsis.

A very different approach has been chosen for the study of related questions in animals. Unfortunately, the ecology of traditional models for genetic studies such as Drosophila or C. elegans is only poorly understood. There are, however, a few organisms in which questions of ecology and short-term evolution have been extensively investigated, among them the guppy. Because husbandry of guppies is fairly simple, and because it is today much easier to generate genomic resources than to develop a detailed ecological picture for a species of choice, the guppy has been selected to study adaptive variation in animals.