Figure 2

Arm is degraded during apoptosis. (A-C') th¹⁰⁹ heterozygous embryo (stage 9, i.e. 60 min after the onset of the morphogenetic arrest in th¹⁰⁹ homozygotes), stained for Arm (A, A') and DE-cadherin (B, B'). (A, B) confocal cross-section; surface view (A', B'). (D-F') Same stage th¹⁰⁹homozygous embryo stained for Arm (D, D') and DE-cadherin (E, E'). (D, E) confocal cross section and surface view(D', E'). (C, C', F, F') Merged images with Arm in green and DE-cadherin in red. Scale bar in (F') for (A-F) represents 10 μm. (G) Western blot probing protein levels of DE-cadherin, Dα-Cat, Arm and Actin in protein extracts of th¹⁰⁹ heterozygous (wt) and th¹⁰⁹homozygous embryos 45 min and 60 min after cephalic furrow formation (indicated as +45 and +60, respectively). (H) Western blot using anti-Arm^Nterm antibody to probe extracts of balancer controls (TM3) and th¹⁰⁹ homozygous embryos at time points 60 min after cephalic furrow formation; note that anti-Arm^Nterm antibody recognizes full length Arm protein in controls, but no degradation products in th¹⁰⁹ homozygotes. Actin was used as a loading control, because we found that Actin is not apparently cleaved in th¹⁰⁹ homozygous embryos at the time points indicated.