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Fig. 7. The final level of SMAD response is sensitive to dpp gene dosage.
Confocal projections of embryos stained for Medea (E,F) or PMAD (A-D).
2Xdpp embryos are wild-type (WT) controls, 1Xdpp and
3Xdpp are dppH46/dpp+ and
dpp+ P{dppH+}/dpp+, respectively.
(A) Stage 7, 3Xdpp embryos show an expanded dorsal region of PMAD
staining, which broadens in the trunk region as amnioserosa cells flatten. (B)
Stage 7 1Xdpp embryos have weaker PMAD staining. Stage 8
1Xdpp embryos (D,F) have substantially weaker SMAD responses than WT.
(D) Stage 8, 1Xdpp embryo with undetectable PMAD staining and partially
ventralized phenotype. (E) In stage 9 WT has strong nuclear Medea accumulation
in the amnioserosa and dorsal-midline of cephalic region. (F) Stage 9
1Xdpp embryos often have a weak stripe of nuclear Medea accumulation
in the cephalic region and variable but low levels in amnioserosa nuclei.