Dscam and neuronal uniqueness

In the fruit fly Drosophila the gene encoding the cell adhesion molecule Dscam generates alternatively spliced mRNAs that can be translated into thousands of different protein isoforms. Three recent papers show that isoform-specific homophilic Dscam interactions cause dendritic branches of the same neuron to avoid each other (Hughes et al., 2007; Soba et al., 2007; Matthews et al., 2007). This process ensures the correct patterning of dendrites in the peripheral nervous system.