Expression profiling of isolated dendritic arborization (da) neurons of Drosophila

Paper abstract: The transcription factors Abrupt (Ab) and Knot (Kn) act as selectors of distinct dendritic arbor morphologies in two classes of Drosophila sensory neurons, termed class I and class IV, respectively. We performed binding-site mapping and transcriptional profiling of isolated these neurons. Their profiles were similarly enriched in cell-type-specific enhancers of genes implicated in neural development. We identified a total of 429 target genes, of which 56 were common to Ab and Kn; these targets included genes necessary to shape dendritic arbors in either or both of the two sensory subtypes. Furthermore, a common target gene, encoding the cell adhesion molecule Ten-m, was expressed more strongly in class I than IV, and this differential was critical to the class-selective directional control of dendritic branch sprouting or extension. Our analyses illustrate how differentiating neurons employ distinct and shared repertoires of gene expression to produce class-selective morphological traits. da neurons were isolated by magnetic bead sorting from larvae of the following three genotypes and obtained genome-wide expression profiles: larvae expressing a cell-surface marker mCD8:GFP alone (Control), and larvae ectopically expressing Abrupt (Ab ME) or Knot (Kn ME) together with mCD8:GFP in all classes of da neurons. 3 biological replicates were collected.