We are interested in understanding the mechanisms and evolution of developmental plasticity, i.e. how developmental processes change in response to the environment. As a study system, we focus on the plasticity of the Caenorhabditis germline in different environments. The C. elegans germline is a mechanistically well-tractable system and shows a high degree of environmental sensitivity, thus providing an ideal experimental model to study plasticity. Our first aim is to understand the significance of this plasticity in experimental environments mimicking ecologically relevant environmental conditions, and how different environments change this plastic response. In our initial analyses, we have started to characterize how germ cell proliferation, entry into meiosis and apoptosis are modified in animals exposed to conditions, such as liquid, starvation, food source, temperature shifts, osmotic or oxidative stress. We now intend to study the mechanisms by which the different environment induce plasticity in these germline processes and how this contributes to germline integrity in variable environmental contexts. Our second aim is to quantify natural variation in germline plasticity within and among species to study the evolution of plasticity, and to ultimately map genetic factors underlying a differential plastic response. We will present our initial comparison of germline differences in 15 isolates of the three hermaphroditic species (C.elegans, C.briggsae and C.sp.11) and how these isolates differ in germline plasticity across different environments.