Fig. 3. Onset and progression of tendrils phenotype. (A-C) tendrils^13-8 DB terminal cell clones (yellow) and contralateral tendrils⁺ control (red) at larval stages indicated. Lumen tracings of corresponding bright-field images are shown at right. At early L2 tendrils^13-8 mutant cells resemble tendrils⁺ cells, whereas tendrils^13-8 clones examined later in development have progressively more severe phenotypes. (D,E) tendrils^13-8 DB terminal cell clone imaged live in early L3 larva (D, GFP fluorescence; D', bright-field) and again 48 hours later (E,E'). Numbers indicate specific branches; dots indicate distal end of air-filled lumen. Terminal branches (1, 2, 3) are lost and their lumens compact into soma during a 48-hour period. Contralateral tendrils⁺ control cell (not shown) continued to develop normally. (F,G) Similar analysis of tendrils^6-66 DB terminal cell clone. The convoluted lumens of branches 2 and 3 are displaced into the more proximal branch and branch 2 becomes extremely thin (broken line) during 48-hour period. The lumen of branch 4 is also displaced, as monitored by the position of a lumen spur (arrowhead) with respect to branch 3. (H-K) Effect of elimination of maternal tendrils⁺ function on tendrils phenotype. Fluorescent images (H-K) and bright-field close-ups (H'-K') of tendrils⁺ (H) and tendrils^- (I,J) DB terminal cell clones generated in animals derived from tendrils⁺ (H-J) or tendrils^- (K) eggs. tendrils phenotype (I,I',J,J') is not enhanced when maternal tendrils⁺ is eliminated (K,K'). Scale bars: 25 µm. Bar in C applies to A-C; bar in E' applies to D,E; bar in G' applies to F,G; bar in K applies to H-K; bar in K' applies to H'-K'.