Figure 1.

PcG genes are required cell-autonomously for proper dendrite development of class IV da neurons. (A) MARCM clone of the class IV neuron ddaC. The range of branching patterns observed in Frt2A clones are depicted as camera lucida of additional representative clones below the image. Clone genotype: w, Gal4^elav, UAS-mCD8∷GFP/+; Frt2A/Frt2A. Dorsal is up and anterior is left in this and all subsequent images. Bar, 50 μm. (B) E(z)^−/− class IV ddaC clones fail to properly cover the receptive field and show a significant reduction in dendritic branching. The phenotypic range of E(z)^−/− ddaC clones is represented as camera lucida of three independent clones below the image. Clone genotype: w, Gal4^elav, UAS-mCD8∷GFP/+; E(z)⁶³ Frt2A/E(z)⁶³ Frt2A. (C) Pc^−/− class IV ddaC are also defective in both dendrite arborization and dendritic branching. Camera lucida represent the phenotypic range of Pc^−/− ddaC mutant clones of the genotype w, Gal4^elav, UAS-mCD8∷GFP/+; Pc^XT109 Frt2A/Pc^XT109 Frt2A. (D) Average number of total dendrite branches in wild-type (wt), E(z)⁶³, Pc^XT109, Su(z)⁴, esc²¹, or esc²¹/+; Pc^XT109 ddaC MARCM clones. Error bars represent one standard deviation and asterisks (*) denote p < 0.05 relative to wild-type controls. (E) Total dendritic length of wild-type, E(z)⁶³, Pc^XT109, Su(z)⁴, esc²¹, or esc²¹/+; Pc^XT109 ddaC MARCM clones. (F) Area of dendritic field covered by wild-type, E(z)⁶³, Pc^XT109, Su(z)⁴, esc²¹, or esc²¹/+; Pc^XT109 ddaC MARCM clones. (G–I) Live image of third instar class IV ddaC neuron visualized using pickpocket-Gal4, UAS-mCD8∷GFP in wild-type (G), Pc¹/+ heterozygous (H), or Pc¹/E(z)⁶³ trans-heterozygous (I) larva. Anterior is left, and dorsal is up. Bar, 50 μm. (J) Quantification of dendrite branchpoints normalized to total dendritic length in ddaC of wild-type, Pc¹/+, E(z)⁶³/+, Su(z)12⁴/+, Pc¹/E(z)⁶³, or Pc¹/Su(z)12⁴ larvae. Error bars represent one standard deviation and asterisks (*) denote p < 0.05 relative to wild-type controls.