Figure 3. EXC-6 Localizes to, and Regulates, Leading-Edge F-Actin in the EC(A-A00) Maximum projection of a confocal z stack from a transgenic animal immunostained to visualize (A) Venus::EXC-6 and (A') ERM-1, which binds apical F-actin (Gobel et al., 2004). Merge of Venus::EXC-6 and ERM-1 is shown in (A''). In this region of the EC, which includes the cell body (the EC nucleus is marked),Venus::EXC-6 accumulates in basolateral microfilaments and does not colocalize with apical ERM-1.(B-B0000) Maximum projection of spinning disk confocal z sections of a live wild-type hermaphrodite showing (B) cytoplasmic CFP, (B0) LifeAct::TagRFP, and (B00) Venus::EXC-6. Area boxed in (B-B00) is magnified in (B000 and B0000). Arrowhead marks the extent of apical lumen, as seen with cytoplasmic CFP (B). Note leading edge F-actin structure past this point of lumen extension in (B0), magnified in (B000). Venus::EXC-6 (B00) colocalizes with F-actin only at this leading-edge structure (B0000). Post., posterior.(C-C0000) Maximum projection of spinning disk confocal z sections of a live
exc-6(0) hermaphrodite showing (C) cytoplasmic CFP, (C0) LifeAct::TagRFP, and (C00) Venus::EXC-6(I213A). Mutation of the conserved actin-binding Ile213 abolishes rescue of
exc-6(0) (Figure 1F) and colocalization with the aberrant leading-edge Factin structure (C0-C0000), without altering Venus::EXC-6 accumulation on basolateral microfilaments (arrows in C00). Ant., anterior.