Final Activity Report Summary - CELLIMAGE (Advanced Cell Imaging Approaches in Developmental Biology) The main scientific objectives of this project were to study basic developmental processes using imaging techniques in vivo in the three widely used model systems - nematodes, insects (Drosophila and Tribolium) and mice. These processes included neurogenesis, neuronal migration, learning and memory, synaptic plasticity and body axis formation. All of these events have been the focus of respective groups over the last few years. The Averof group developed transgenic markers and live imaging techniques in an emerging model insect (Tribolium), which allowed us to record cell behaviour during the process of axial growth. By developing an embryo culture protocol, we were also able to study the dynamics of segmentation gene expression during Tribolium germband elongation. The Delidakis group has been studying Notch signalling, a fundamental cell signalling pathway that is deployed repeatedly during neurogenesis. Notch signalling needs to be dynamically modulated in space and time; the group has started pursuing this question by using several fluorescent reporter of Notch activity in Drosophila. The Karagogeos group has been studying the role of guidance cues (adhesion molecules of the immunoglobulin superfamily and intracellular mediators) in migrations in the central nervous system of mice. The group has generated mice deficient in some of these cues and has started visualizing and understanding how neurons move and whether alterations are noticed in mutant environments. The Tavernarakis group aims at identifying genes required for the sensory transduction and integration that forms the basis of learning and memory in the nematode. The group investigated synaptic plasticity in nematode neurons and analysed any anatomical or molecular changes that follow training experience. They generated and analysed nematode mutants with altered or impaired capacity for associative learning. They monitored neuronal function in vivo by the use of transgenic animals harbouring specific GFP reporters targeted to specific sets of neurons. Finally, the latter two groups collaborated in the study of a neuronal recognition protein in worms and they showed that it regulates axon growth and morphogenesis.
