Figure 5. Cytonemes cross ptc−/− mutant clones at the A/P compartment border.
(A) A ptc16 null clone in the A compartment abutting the A/P compartment border of a wing disc co-labelled with α-Hh and α-Ptc antibodies. Note that both Ptc and Hh proteins are detected anterior to the clone in the A compartment (arrowheads). (B) P compartment cytonemes extend through a ptc−/− clone (arrowheads). Lateral and basal sections of a ptc−/− clone (absence of βGal) in the A compartment with Ihog-RFP expression in the P compartment to visualize cytonemes (FRT42D ptc16 / hh.Gal4, tub.Gal80ts>UAS.ihog-RFP wing disc after 24 hr at the restrictive temperature) co-labelled with α-βGal and α-Ptc antibodies. (C) First and last time frames from Video 6 displaying a lateral view of GMA-GFP signal to easily visualize cell perimeters together with a Z-projection of GMA-GFP where filopodia are shown (top panels) or with a lateral view of nuclear RFP to distinguish between wild-type (magenta nuclei) and ptc−/− mutant (absence of magenta nuclei) territories (bottom panels). Scale bars represent 10 μm. (C’) Graph showing extent distribution over time of GMA-GFP filopodia emanating from Hh-producing cells. Notice that there is no difference between filopodia crossing a wild-type (magenta) or a ptc−/− mutant (grey) clone territories. (D) A ptc16 clone induced in the A compartment abutting the compartment border in a dpp.LexA>LexAop.CD4-GFP11>LexAop.ihog-RFP / tub.Gal80ts, hh.Gal4>UAS.CD4-GFP1-10 wing disc after 24 hr at the restrictive temperature and labelled with α-βGal antibody to identify the mutant clone (absence of βGal). Note the GRASP signal is not visualized laterally (asterisk). Note also that basal cytonemes cross the ptc−/− clone in region 1 but not in region 2, and that the GRASP signal is restricted to region 1 and absent from region 2 (arrowheads). E) Another ptc−/− clone induced in a disc with the same genotype as in D showing the interaction between cytonemes from wild type cells anterior to the clone and cytonemes from the P compartment. Note the GRASP signal along basal cytonemes from wild type A compartment cells that traverse the ptc−/− clone (arrows). The data shown were consistent in at least three independent experiments with an average of 5–10 discs in each experiment. Bars, 10 µm.
Figure 5—figure supplement 1. Cytonemes from Hh-producing cells are still formed in mutants that modify Hh reception.
Figure 5—figure supplement 2. Cytonemes are still present in absence of Hh ligand.
Figure 5—figure supplement 3. Manual tracking of filopodia arising from Hh-producing abdominal histoblasts cells crossing either a ptc mutant or a wild-type territories.
