Figure 4.
Figure 4. C-GAP promotes spatial organization of apical RhoA pathway signaling. (A) Images from live control (white shRNA) or C-GAP shRNA embryos expressing myosin::GFP and membrane::RFP. Whereas control embryos form myosin fibers or nodes spanning the apical surface, C-GAP shRNA embryos with mild ventral furrow phenotypes have diffuse myosin spread across the apical surface or highly condensed myosin in severe phenotypes, resembling cells that lose adhesion. (B) Linescans across myosin structures within individual cells in Control (n = 20) or C-GAP shRNA (n = 25) reveal that myosin forms less condensed or organized structures in C-GAP shRNA embryos (shaded areas represent ±SD). (C) Images from live control or C-GAP shRNA embryos expressing GFP::ROCK and membrane::RFP. Instead of one condensed ROCK focus in each control cell, C-GAP shRNA results in a more diffuse ROCK (mild) spreading across the entire apical domain, or highly condensed ROCK (severe), where the furrow ultimately falls apart and does not invaginate. (D) Images from live control (C-GAP heterozygous mutant) and C-GAP homozygous, germline mutant embryos expressing GFP::ROCK and membrane::RFP. Both control and C-GAP mutant embryos have identical ROCK localization phenotypes to shRNA embryos. (E and F) Images from live embryos expressing E-cadherin::GFP and myosin::RFP. (E) Apical E-cad localization is restricted to cell-cell contacts in control shRNA embryos, but E-cad spreads across the apical surface (arrowheads) in C-GAP shRNA. (F) E-cad becomes condensed with concentrated myosin structures in severe C-GAP shRNA embryos that appear to lose adhesion. (G) Cross sections from live embryos expressing GFP::ROCK and Membrane::RFP demonstrating C-GAP restricts ROCK activity to apical domain. In control shRNA embryos, ROCK localization is restricted to the apical cortex, but C-GAP shRNA embryos have both apical (arrowhead) and some basolateral (arrow) accumulation of ROCK. "A" is apical and "B" is basal. (H) Cross sections from live embryos expressing GFP::ROCK showing that C-GAP mutant embryos also have some basolateral accumulation of ROCK. Bars: (B) 1 µm; (A and C–H) 5 µm.

C-GAP promotes spatial organization of apical RhoA pathway signaling. (A) Images from live control (white shRNA) or C-GAP shRNA embryos expressing myosin::GFP and membrane::RFP. Whereas control embryos form myosin fibers or nodes spanning the apical surface, C-GAP shRNA embryos with mild ventral furrow phenotypes have diffuse myosin spread across the apical surface or highly condensed myosin in severe phenotypes, resembling cells that lose adhesion. (B) Linescans across myosin structures within individual cells in Control (n = 20) or C-GAP shRNA (n = 25) reveal that myosin forms less condensed or organized structures in C-GAP shRNA embryos (shaded areas represent ±SD). (C) Images from live control or C-GAP shRNA embryos expressing GFP::ROCK and membrane::RFP. Instead of one condensed ROCK focus in each control cell, C-GAP shRNA results in a more diffuse ROCK (mild) spreading across the entire apical domain, or highly condensed ROCK (severe), where the furrow ultimately falls apart and does not invaginate. (D) Images from live control (C-GAP heterozygous mutant) and C-GAP homozygous, germline mutant embryos expressing GFP::ROCK and membrane::RFP. Both control and C-GAP mutant embryos have identical ROCK localization phenotypes to shRNA embryos. (E and F) Images from live embryos expressing E-cadherin::GFP and myosin::RFP. (E) Apical E-cad localization is restricted to cell-cell contacts in control shRNA embryos, but E-cad spreads across the apical surface (arrowheads) in C-GAP shRNA. (F) E-cad becomes condensed with concentrated myosin structures in severe C-GAP shRNA embryos that appear to lose adhesion. (G) Cross sections from live embryos expressing GFP::ROCK and Membrane::RFP demonstrating C-GAP restricts ROCK activity to apical domain. In control shRNA embryos, ROCK localization is restricted to the apical cortex, but C-GAP shRNA embryos have both apical (arrowhead) and some basolateral (arrow) accumulation of ROCK. "A" is apical and "B" is basal. (H) Cross sections from live embryos expressing GFP::ROCK showing that C-GAP mutant embryos also have some basolateral accumulation of ROCK. Bars: (B) 1 µm; (A and C–H) 5 µm.

This Feature Is Available To Subscribers Only

or Create an Account

Close Modal
Close Modal