Fig. 7. Nuclear svp mRNA localisation and attenuation of hb expression in stg mutant embryos. Dashed line indicates the midline. Cells expressing high levels of Hb protein are outlined. (A) Double labelling for Hb protein (green) and svp mRNA (magenta). Cells that express high levels of Hb, do not express svp mRNA. In contrast to that, svp-expressing cells show low levels of Hb protein. Note the complete colocalisation of the nuclear Hb protein with svp mRNA. (B) Double labelling for Hb (green) and Svp protein (magenta). There is no Svp protein detectable in cells that show high expression of Hb protein. Those cells that are weakly Hb⁺ show a concomitant low level of Svp protein. (C) Double labelling for hb mRNA (green) and svp mRNA (magenta). Although hb mRNA is enriched in the cytoplasm of the NBs, the svp mRNA is found mainly in the nucleus. (D) Double labelling for Hb protein (green) and hb mRNA (magenta). Low Hb protein levels correlate with low hb mRNA levels, suggesting a transcriptional downregulation of hb by Svp. Scale bar: 20 µm.