Fig. 3. Diverse neuron types broadly implement distal ALE isoforms and extended 3’ UTRs.

a, b Using the body sNuc-seq dataset, we used classifications of ventral nerve cord (VNC) (part of the central nervous system, CNS) and peripheral nervous system (PNS) and compared these to non-neural cell types (muscle and follicle cells shown here, others are shown in Supplementary Fig. 2). In all these comparisons, it is apparent that CNS (a) and PNS (b) neurons have unidirectional preference to express longer tandem 3’ UTRs as well as distal ALE isoforms. c, d Genome browser tracks of individual genes highlights that the preferential expression of extended 3’ UTRs (Dscam1, c) or distal ALE (Vrp1, d) isoforms in head 3’-seq data is mirrored by their expression in CNS and PNS neurons. e–g Expression of 3’ isoforms can provide cell type information, where intrinsic gene expression patterns do not. e UMAP of dominant cell types in the Drosophila body. f, g APA analysis in individual cells. Dscam1 and Vrp1 are broadly expressed genes that do not intrinsically contribute to cell classification. However, expression of the Dscam1 extended 3’ UTR (f) and the Vrp1 distal ALE isoform (g) are indicative of neurons, even in individual cells.