Fig. 4

Invading Sheath Cells Differentiate into Vacuolated Cells

(A and B) Projections of confocal stacks of 72 hpf WT and cavin1b^−/− larvae expressing rcn3:GFP-rab32a and col9a2:mcherry. Brackets mark areas of vacuolated cell collapse and sheath invasion; arrows point to new vacuoles in sheath cells.

(C and D) Following invasion, sheath cell vacuoles (arrows) enlarge. Intact primary vacuolated cells are traced with dashed lines. The asterisks mark an intact vacuolated cell.

(E) Confocal images of live sheath cells obtained from 48 hpf embryos expressing col9a2:mcherry and rcn3:GFP-rab32a. Cells were treated with suramin and AR-C 118925XX (AR-C) or ATPγS/UTPγS or left untreated for 2 hr. Arrows point to newly formed vacuoles.

(F) Quantitation using one-way ANOVA followed by multiple comparisons using Tukey’s test, ^∗∗∗p < 0.001; n.s., not significant; n = 3 experiments.

(G–O) LSM imaging of cavin1b mutants expressing col8a1a:GFPCaax and col9a2:mcherry.

(G–I) 3.6-mm fish. Arrows point to vacuolated sheath cells; asterisks mark a primary vacuolated cell.

(J–L) 4.5-mm cavin1b^−/− fish showing new vacuolated cells that retained col9a2:mcherry expression (arrows) next to a primary vacuolated cell (asterisks).

(M–O) 4.3-mm cavin1b^−/− fish with remnants of primary vacuolated cells (arrow), a primary vacuolated cell (asterisk), and newly differentiated vacuolated cells (blue arrows).

Scale bars, 50 μm. Error bars are SD. See also Figures S3 and S4.