Fusion of the Eve-expressing DA1 founder cell in various mutant
embryos. (A-O) Abdominal segments 3-5 are shown in embryos stained
with anti-Eve to mark the nuclei of the DA1 muscle and two pericardial cells
per hemisegment. (A-C) Wild-type, (D-F)
mbcD11.2/mbcD11.2, (G-I)
snsXB3/snsXB3, (J-L) Df(1)w67k30/Y and
(M-O) lmd1/lmd1. The founder cell for DA1
remains mononucleate in embryos lacking mbc, kirre and rst
[Df(1)w67k30], or lmd at developmental stages when
significant fusion is observed in wild-type embryos (arrows). In embryos
mutant for sns, by contrast, the Eve-expressing DA1 founder cell
undergoes limited fusion to generate bi- or tri-nucleate syncitia
(arrowheads). (P) The average number of DA1 nuclei per hemisegment was
quantitated in late stage 15 embryos of each mutant genotype. (Q) The
fusion profile of precursor formation in wild-type and
snsXB3 embryos shown as the average number of DA1 nuclei
per hemisegment. (R) The percentage of embryos observed with any
hemisegments showing DA1 precursor formation. Scale bar: 20 μm.