Fig. 7. Role of Wisp in cytoplasmic polyadenylation in early Drosophila embryos. (A) PAT assays and RT-PCR of bcd, osk and nos mRNAs in embryos from 0-1, 1-2 and 2-3 hours of development, from wild-type, wisp^KG5287 or wisp^KG5287/Df(1)RA47 females. In the absence of Wisp, osk and nos mRNAs are destabilized and the poly(A) tails of bcd mRNA are not elongated in embryos. sop mRNA was used as a control. The sop RT-PCR is the loading control for bcd, osk and nos RT-PCR. For bcd mRNA, PAT assays from ovaries were loaded to show the poly(A) tail elongation between ovaries and early embryos in the wild type. (B) In situ hybridizations of 0- to 1-hour wild-type and wisp^KG5287/Df(1)RA47 embryos showing bcd, osk and nos mRNA. (C) Immunostaining of 0- to 1-hour embryos with anti-Bcd, anti-Nos and anti-Osk antibodies, showing that the lack of poly(A) tail elongation in wisp^KG5287/Df(1)RA47 mutant embryos, leading or not to mRNA decay, results in the lack of corresponding proteins. Note that the lack of nos mRNA/protein at the posterior pole could also result from the lack of Osk protein, as Osk is required for nos mRNA stabilization.