Fig. 8. SOG reduces the width and increases the level of SMAD response. Embryos from sog heterozygous parents stained for Medea (A,C,E) or PMAD (B,D,F), here shown for sog^U2 (C-F) compared with wild type (A,B). (C,D) One aberrant class, inferred to be sog^U2/+, has a variably broader dorsal stripe of nuclear SMAD responses. (E,F) The other aberrant class, inferred to be sog^U2 hemizygous males, has a low-level response over the dorsal half of the embryo. A region of cells with predominantly nuclear Medea is indicated (E, arrow). Anterior is leftwards.