The range of the Notch signal. Clonal analysis of several neurgenic mutants.

<p>The clones are labelled either by absence or presence (MARCM) of the GFP marker and outlined by the dashed lines in (C, F, I, L, M, P). Clones are induced with hsFlp during the first instar stage. (A–D) A <i>kuz</i> clone in <i>mib1</i> mutant wing discs. Clones are labelled by the loss of GFP. (B–C) Magnifications of the regions highlighted in (A) with the lower arrow. Arrows in (B–D) highlight the regions where the mutant SOPs contact wildtype cells. Gbe+Su(H)-lacZ is elevated in the wildtype neighbours contacting mutant SOPs. (D) Magnification of the regions highlighted in (A) with the upper arrow. (E–H) An <i>aph-1</i> clone in <i>mib1</i> mutant wing discs labelled by the loss of GFP. (F–H) Magnifications of the regions highlighted in (E) with the arrow. The mutant SOPs induce Gbe+Su(H)-lacZ in the surrounding <i>mib1</i> mutant cells. (I, J) A <i>Ser Dl</i> double mutant clone (case1) labelled through the absence of GFP. The arrow points to the mutant SOP that developed one cell diameter away from the wildtype SOP (arrowhead). (G–P) Examples for case 2. (K–P) <i>kuz</i> MARCM clones in wildtype discs, positively labelled with GFP. The SOPs are marked by the A101-lacZ, a lacZ insertion in <i>neur</i>. (L, M) and (O, P) are magnifications of the regions highlighted with the arrows in (K) and (N) respectively. The arrowhead in (L, M) point to a wildtype SOP that is located one cell diameter away from a mutant SOP (arrow), the arrowhead in (O, P) to a wildtype cell that is in direct contact with mutant SOPs (arrows). In both cases the wildtype SOP cannot be inhibited from adopting the SOP fate by the mutant SOPs close by. (Q) A MARCM clone of <i>aph-1</i>. The arrowhead points to the wildtype SOP (arrowhead) located near a mutant one (arrow). As in the case of <i>kuz</i> clones, the wildtype SOP cannot be inhibited from adopting the SOP fate by the mutant SOPs close by. (R–T) A <i>Psn</i> mutant cell clone labelled through absence of GFP. The arrow in (R) highlights the region magnified in (S, T). The arrowhead in (S, T) points to the wildtype SOP that is surrounded by mutant ones (S, T, arrows). Also in this case, the wildtype SOP form in the presence of the surrounding mutant SOPs. White scale bar 50µm; cyan scale bar 10µm.