The reduction of Dscam1 diversity affects axonal branching in MS neurons.

See also S7–S9 Figs. (A) Schematic of the axon trajectory of a single MS neuron within the VNC. Branch segments were assigned different colors for scoring. Representative dye tracing images of the wild-type and Dscam1 mutant flies. Dashed circles indicate the location of the lateroanterior branch. ns, not significant; *p p p t test, two-tailed). Scale bar, 50 μm. (B) Quantitative analysis of the length of lateroanterior branch in wild-type and Dscam1 mutant flies. Numbers in parentheses represent the number of pSc neurons observed in each genotype. (C) The average length of lateroanterior branch positively correlated with the number of variable exons 4, 6, and 9. The dashed curves show the spectra of phenotypic variation among different variants. (D) A comparison of phenotype–diversity correlates among variable exon 4, 6, and 9 clusters. Reducing Dscam1 diversity affected MS axonal branching in an exon cluster–specific manner. Data used to generate graphs can be found in S1 Data. Dscam1, Down syndrome cell adhesion molecule 1; MS, mechanosensory; VNC, ventral nerve cord; WT, wild type.