Fig. 2. SoxN is necessary and sufficient to activate svb
expression/direct denticle formation. (A,B) svb RNA
expression in stage-14 wild-type (wt; A) and SoxNGA1192
(B) embryos. (C) Ectopic denticle formation in an
enGal4-UAS-SoxN larva. The arrow indicates ectopic
denticle formation in the anterior row of the En-expressing stripe. Rows are
labeled 1-6. (D,E) Misexpression of SoxN with the
armVP16Gal4 driver results in ectopic denticle formation (indicated
by brackets; D) in those areas where ectopic expression of svb occurs
(E); note that svb is expressed in broad stripes but is not
ubiquitous. (F) Anti-GFP staining (green) of stage-12
armVP16Gal4-UAS-SoxN-YFP embryos; note that
armVP16Gal4 drives SoxN expression in broad stripes but is
not ubiquitous. The red staining indicates the ventral midline. (G-I)
Misexpression of SoxN with the wgGal4
(wgGal4-UAS-SoxN-YFP) driver results in ectopic
denticle formation. (G) Ectopic denticle formation in
wgGal4-UAS-SoxN-YFP larvae. (H) Cuticle and
anti-YFP staining of stage-17 wgGal4-UAS-SoxN-YFP
embryos; note that SoxN directs ectopic denticle formation in a
cell-autonomous manner. (I) Cuticle and anti-HA staining of stage-17
wgGal4-UAS-SoxN-UAS-wg embryos;
note that concomitant misexpression of SoxN and wg results
in ectopic denticle formation in a cell-autonomous manner.