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. 2012 Mar 19;7(3):e33634. doi: 10.1371/journal.pone.0033634

Figure 8. Cut-induced de novo dendritic branching and filopodia formation requires Trio activity.

Figure 8

(A–D) Live confocal images of class I da neurons (ddaD, ddaE, vpda) at the third larval instar. (G,H) Live confocal images of class IV ddaC neurons. Images were collected at 20× magnification and size bars represents 50 microns. (A,B) Representative images of dorsal ddaD/E neurons (A) and ventral vpda neuron (B) ectopically overexpressing Cut. Cut ectopic overexpression results in class I neurons displaying increased dendritic branching complexity characterized by a high incidence of dendritic filopodia emanating from the primary branches. (C,D) Representative images of dorsal ddaD/E neurons (C) and ventral vpda neuron (D) in which Cut ectopic overexpression is combined with knockdown of trio via UAS-trioRNAi. As compared to Cut overexpression, trio knockdown results in strong suppression of the Cut phenotype, particularly with respect to dendritic filopodia. (E) Quantitative analyses reveal a significant reduction in the total number of dendritic terminals in neurons expressing trioRNAi relative to Cut ectopic overexpression alone. (F) Quantitative analyses reveal no statistically significant difference in total dendritic length. (G) Representative image of class IV ddaC neuron expressing UAS-cutRNAi. (H) Representative image of ddaC neuron simultaneously expressing UAS-cutRNAi and UAS-trio transgenes reveals partial rescue of cut mutant defects in dendritic branching. (I) Quantitative analyses reveal knockdown of cut via RNAi significantly reduces the total number of dendritic terminals relative to wild-type (WT) controls, whereas Trio overexpression in a cutRNAi background partially rescues the cut mutant phenotype. The total n value for each neuron and genotype quantified is reported on the bar graph. Statistically significant p values are reported on the graph as follows (* = p<0.05; ** = p<0.01; *** = p<0.001). Genotypes: (A,B) UAS-cut/+; GAL4221,UASmCD8::GFP/+; (C,D) UAS-cut/+; GAL4221,UASmCD8::GFP/UAS-trioRNAi; (G) GAL4477,UASmCD8::GFP/+;UAS-cutRNAi/+; (H) UAS-trio/+; GAL4477,UASmCD8::GFP/+; UAS-cutRNAi/+.