Fig. 4. Tethered Nos can repress CycB but not hb. (A) Accumulation of CycB (green) monitored in the primordial germ cells, marked by accumulation of Vasa (red). The relevant maternal genotypes are: (1) CycB⁺/CycB⁺ (wild type, wt), (2) CycB³/CycB⁺; CycB(2x MS2hp), (3) CycB³/CycB⁺, Nos-CP; CycB(2x MS2hp), (4) CycB³/CycB², Nos-CP; pum^ET3 / CycB(2x MS2hp), pum^Msc (all transgenes single-copy). (B) Accumulation of Hb (green) in embryos from wild-type females or females bearing the indicated transgenes, with pole cells marked by arrowheads and nuclei labeled with TOPRO3 (red). Note that the accumulation of Hb in somatic nuclei at the posterior of the transgenic embryos derives from both torso-dependent zygotic transcription and unrestrained translation of the maternal hb(2x MS2hp) mRNA, whereas wild-type embryos contain only the former source of Hb (as in Fig. 2).