Assaying Mutants of Clathrin-Mediated Endocytosis in the Fly Eye.

Clathrin-mediated endocytosis plays essential roles both during and after development, and loss-of-function mutants affected in this process are mostly not viable. Different approaches have been developed to circumvent this limitation, including resorting to mosaic model organisms. We here describe the use of FLP/FRT-mediated mitotic recombination to generate Drosophila melanogaster having homozygous mutant eyes while the rest of their body is heterozygous. We then present a detailed protocol for assessing the consequences of these loss-of-function mutations on endocytosis in the photoreceptors of living fruit flies by recording electroretinograms.