Glial-cell specific expression in fruit flies
Dr. Ulrike Gaul and graduate student Malte Kremer, from the Gene Center of the LMU Munich, study the role of glial cells in the development and function of the fruit fly brain. As visiting scientists in the Visitor Program, they collaborated with scientists at Janelia to characterize glial-cell-specific expression in fruit flies.
GAL4 line driving expression of a multicolor membrane marker under control of Hs-Flp in astrocyte-like glia. Stochastic expression of the marker is evenly distributed in all major regions of the brain, revealing the morphologies of individual glial cells.
The morphology of glia in the adult Drosophila nervous system
The glia in the Drosophila adult brain have been only partially described, and while glial-specific drivers had been found within the Janelia collection of nervous system GAL4 drivers, they were not fully annotated or characterized. In this visitor project, Dr. Ulrike Gaul and graduate student Malte Kremer sought to use the drivers in the Janelia collection to identify all glial cell types present in the adult brain and to characterize them with regard to their number, morphology, and intercellular interaction. Screening the entire collection of 7,000 GAL4 lines, they found 800 with glial expression and 250 that are expressed specifically in glia. Among these 250, they identified not only lines that are generally expressed in all cells of a given glial cell type but also lines with regionally restricted expression, especially in the optic lobes and the ventral nerve cord. This project will contribute to the understanding of the diversity and complexity of glial cell anatomy and provide important tools for future studies of glial function.
Calcium imaging from the neuromusculature of freely behaving C. elegans
Dr. William Schafer and graduate student Victoria Butler, from the Medical Research Council Laboratory of Molecular Biology at Cambridge, are collaborating with scientists at Janelia through the Visitor Program to understand how patterns of neuromuscular activity generate C. elegans locomotor behavior.
The coordination of complex body movements uses sensory feedback to detect forces associated with body movements. The molecules involved in the sensory feedback as well as the mechanism by which the neural circuits regulate locomotion are not well-understood. In collaboration with Drs. Dmitri Chklovskii and Rex Kerr at Janelia, Dr. William Schafer and graduate student Victoria Butler have developed a tracking microscope that allows simultaneous recording of nematode behavior and neuromuscular calcium transients. They have generated transgenic lines expressing the fluorescent calcium indicator GCaMP3 in body wall muscle and subclasses of motor neurons. The aim now is to use these lines to observe the muscle and neuron activity in behaving worms under different environmental conditions and in different mutant backgrounds. They hope to use the data collected to develop mechanistic models for C. elegans locomotion behaviors.