Fig. 8. spen is not required for Wg signaling in the embryo. (A,D)
Micrographs of cuticles of wild type (A) and embryos containing transgenes
P[da-Gal4] and P[UAS-spenDN]III (D)
reared at 25°C. Expression from P[UAS-spenDN] has
variable effects on cuticle patterning, ranging from wild type
(P[UAS-spenDN]II at 25°C, data not shown),
moderate reduction of denticles (D) to complete disruption of cuticle
formation (P[da-Gal4],
P[UAS-spenDN]III containing embryos reared at
29°C, data not shown). (B,C,E,F) Confocal images of stage 11 embryos
containing P[prd-Gal4] and either P[UAS-TCFDN]
(25°C; B,C) or P[UAS-spenDN]III (29°C;
E,F). Samples were stained for En (B,E) or Slp1 (C,F). En and Slp1 stripes
remain wild type in spenDN-expressing embryos. (G-I)
Confocal images of stage 13 wild-type embryos (G) and embryos containing
transgenes P[twi-Gal4] and
P[UAS-spenDN]II (H,I) reared at 25°C.
Expression from P[UAS-spenDN] has variable effects on the
Eve pericardial expression, ranging from wild type (H) to an increase in
Eve-positive cells (I). Some embryos containing transgenes
P[twi-Gal4], P[24B-Gal4] and
P[UAS-spenDN]II reared at 25°C or 29°C
also display disorganization of Eve-expressing cells or occasional gaps
missing Eve expression, in addition to an overall increase in Eve-positive
cells (data not shown). These effects are qualitatively different from a
blockage of Wg signaling [ectopic denticles, loss of En (B) and Slp-1 (C)
stripes and loss of Eve in pericardial cells].