An image-based approach to determine the kinetics of polyQ aggregation in the neurons of C.elegans

Abstract

Protein aggregation is a pathological hallmark of a wide range of neurodegenerative diseases. The aggregation processes at molecular level have been extensively studied in vitro. However, The mechanism of protein aggregation in vivo is less established. Kinetic in vivo studies have been performed using the model organism Caenorhabditis elegans. Fluorescently labelled polyglutamine (polyQ) expressed in body wall muscle cells of living C.elegans aggregates into small inclusions which can be easily visualized using fluorescence microscopy. In this study, we take advantage of this model to determine the kinetics of polyQ aggregation in the neurons. We provide a novel image-based approach to quantitatively analyse the number of aggregates over time. Our results show that inclusions can be visualized and characterized using fluorescence confocal imaging in living C.elegans expressing pan-neuronal polyQ. Furthermore, the formation of inclusions is time, concentration and length dependent. One striking observation in this study was that only a subset of neurons contained aggregates. This study improves our understanding of aggregation mechanisms in the neurons of a living organism which is a great contribution to research focused on understanding human diseases.