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Fig. 3. Epistatic analyses between nti, Notch and fng. In all
figures, Wg expression is shown in purple and somatic clones that lack
nti function, and/or that overexpress specific genes, are shown in
green. Anterior is towards the left and dorsal is upwards. (A) nti
somatic clones showed cell-autonomous loss of Wg expression. Higher
magnifications of the clones at the DV border are shown in the insets. y w
hs-flp/+; FRTG13 nti/FRTG13 tubP-GAL80;
tubP-GAL4/UASGFP larva wing imaginal disc is shown. nti
homozygous clones are shown by GFP fluorescence (green). (B) Cell-autonomous
Wg ectopic expression was detected when an activated form of Notch was
expressed in nti mutant cells (arrowhead) as in wild-type cells (data
not shown), indicating that nti is not needed for NotchICD
function. Genotype of the wing imaginal disc is y w hs-flp/+;
FRTG13 nti/FRTG13 tubP-GAL80; tubP-GAL4/UAS-GFP
UAS-Nact. Thus, GFP indicates nti homozygous cells
overexpressing NotchICD. (C) Overexpression of Notch is
associated with ectopic Wg expression near the DV boundary. The genotype is
y w hs-flp/+; FRTG13/FRTG13 tubP-GAL80;
tubP-GAL4/UAS-GFP UAS-Notch. GFP shows full-length Notch overexpressing
cells. (D) Full-length Notch effect was suppressed in nti mutant
cells, indicating that nti is epistatic to full length Notch
receptor. The genotype is y w hs-flp/+; FRTG13
nti/FRTG13 tubP-GAL80; tubP-GAL4/UAS-GFP UAS-Notch. GFP shows
nti homozygous cells overexpressed for full-length Notch. (E) Ectopic
expression of fng in the ventral compartment of the wing imaginal
disc is associated with ectopic Wg expression near the margin. The genotype is
y w hs-flp/+; FRTG13/FRTG13 tubPGAL80;
tubP-GAL4/UAS-GFP UAS-fng. GFP shows Fngoverexpressing cells. (F) Ectopic
expression of fng in nti mutant cells had no effect on Wg
expression, showing that Nti is essential for Fng function. The genotype is
y w hs-flp/+; FRTG13 nti/FRTG13 tubPGAL80;
tubP-GAL4/UAS-GFP UAS-fng. GFP shows nti homozygous cells
overexpressing Fng.