Extended Data Fig. 2: Genetic perturbation of exosomes or lipophorin particles does not alter the distribution of extracellular Wingless.

a, Expression of dominant-negative Vps4 with hh-Gal4 in the posterior compartment (limited to 8 h with Gal80^ts to avoid pleiotropic effects of sustained VPS4 inhibition) does not affect extracellular Wingless despite disruption of MVB formation indicated by accumulation of ubiquitin. Anterior compartment serves as a control. Dashed line denotes anterior posterior boundary. b, Expression of extracellular Wingless is largely unaffected by the loss of Hrs activity. The posterior compartment was rendered homozygous for a null hrs mutation using the indicated genotype. c, d, Overexpression of the lipophorin receptor Lpr2E–HA for 24 h with the hh-Gal4 driver increases the uptake of ApoL in the posterior compartment but has no effect on extracellular Wingless. The anterior compartment serves as a control. e, Extracellular Wingless and ApoL in wing discs from w118 (control) or homozygotes for a deficiency that removes the two main lipophorin receptors Lpr1/2. The uptake of lipophorin is reduced in the deficiency line but neither total nor extracellular Wingless is altered. Scale bars, 50 μm. All experiments were repeated independently three times with similar results.