Fig. 5
Analysis of SCA3polyQ78 expression in neurons and the effect of Relish in astrocytes on neuronal expression of SCA3polyQ78 or Abeta42. a Inducible expression of SCA3polyQ78 in neurons can be suppressed during development. Control larvae or larvae expressing inducible SCA3polyQ78 were cultured on food with and without quinic acid. Flies expressing inducible SCA3polyQ78 were cultured on food with quinic acid for the times indicated to induce SCA3polyQ78 expression. Levels and aggregation of HA-tagged SCA3polyQ78 were determined in lysates of larvae or fly heads on western blot. Tubulin was used to verify equal loading. b Effect of inducible SCA3polyQ78 on lifespan. Control flies or 4-day-old flies expressing inducible SCA3polyQ78 were cultured on food containing quinic acid and the lifespan was analyzed. c Expression of Relish target genes AttC, DptA and CecA was analyzed in heads of 15-day-old flies expressing SCA3polyQ78 in neurons. d Analysis of modulation of Relish expression specifically in astrocytes on the lifespan of flies expressing SCA3polyQ78 in neurons. Flies expressing SCA3polyQ78 in neurons induced as in b were compared to flies coexpressing astrocyte-targeted Relish RNAi (Relish RNAi #1 or #2) or overexpressing Relish in astrocytes. To induce changes in Relish expression only in adult flies, crosses were kept at 18 °C. 4-day-old progeny were shifted to 25 °C to allow expression of Relish constructs in astrocytes. e Downregulation of Relish expression in astrocytes extends lifespan in an Alzheimer model. Lifespan of control flies and flies expressing Abeta42 in neurons were compared to flies expressing Abeta42 (Aβ42) in neurons and Relish RNAi constructs in astrocytes. Induction of Relish RNAi was done as in d. Genotypes: a -, tub-QS/+; alrm-Gal4/+; nSyb-QF2::tub-QS/+. SCA3polyQ78, tub-QS/+; alrm-Gal4::QUAS-SCA3polyQ78/+; nSyb-QF2::tub-QS/+. b, c Control, tub-QS/+; alrm-Gal4/+; nSyb-QF2::tub-QS/+. SCA3polyQ78, tub-QS/+; alrm-Gal4::QUAS-SCA3polyQ78/+; nSyb-QF2::tub-QS/+. d -, tub-QS/+; alrm-Gal4/+; nSyb-QF2::tub-QS/+. SCA3polyQ78, tub-QS/+; alrm-Gal4::QUAS-SCA3polyQ78/+; nSyb-QF::tub-QS/+; Relish RNAi #1, Relish RNAi #2, or Relish overexpression, as in SCA3polyQ78, but with expression of UAS-Relish RNAi #1 or #2 or UAS-GFP-Relish in astrocytes. e -, alrm-Gal4/+; nSyb-QF2. Aβ42: alrm-Gal4::QUAS-Abeta42/+; nSyb-QF2/+. Relish RNAi (#1 or #2), alrm-Gal4:: QUAS-Abeta42/UAS-Relish RNAi #1 or #2); nSyb-QF2/+