Loss of Cell-Cell Adhesion in arm Mutants

The following stocks containing fluorescent fusion proteins were used: Spider-GFP (95–1) and Resille-GFP (117–2) (Morin et al., 2001 (link)), membrane-mCherry (this paper), myosin-GFP (sqh-GFP; Royou et al., 2002 (link)), and myosin-mCherry (sqh-mCherry; Martin et al., 2009 (link)). To examine cell shape in embryos devoid of a-p polarity, we used the stock w; Resille-GFP; bicoid^E1 nanos^L7 torso-like¹⁴⁶/TM3; Sb. We analyzed embryos from mothers that were homozygous for bicoid^E1 nanos^L7 torso-like¹⁴⁶. To generate arm^M/Z mutants, we created arm^043A01 germ-line clones using the FLP-DFS system (Chou and Perrimon, 1992 (link)). We visualized myosin II in arm^M/Z mutants by generating a stock that was arm^043A01 FRT101/FM7; sqh-GFP. We crossed females of this genotype to w ovo^D FRT101/Y; flp-138 males to obtain arm^043A01 FRT101/w ovo^D FRT101; flp-138/+ females. These females were heat shocked as larvae for 2 h at 37°C each day to induce mitotic recombination in the germ line. We imaged embryos from the following cross: arm^043A01 FRT101/w ovo^D FRT101; flp-138/+ females x FM7/+; flp-138/+ males. Half of these embryos showed loss of cell–cell adhesion, which is consistent with half being rescued zygotically.