BhC4-1-lacZ mRNA expression in a (-57/+40) transgenic line. Thirty micrograms of total RNA extracted from embryos (E), first and second instar larvae (L1,2), third instar larvae (L3), prepupae at 0 h, 3 h, 6 h, 9 h and 12 h, 24 h pupae, adult males (M) and adult females (F) were analyzed by the Ribonuclease Protection Assay using a mixture of two radiolabeled probes. The protected BhC4-1-lacZ RNA mRNA is 617 nt long (BhC4-1-lacZ arrow). The protected Actin mRNA is about 260 nt long (Actin arrow). In lane (y,w), 30 μg of total RNA extracted from embryos of the parental strain y,w were hybridized with both probes. In lanes (3 h prepupae/lacZ) and (3 h prepupae/Actin), 30 μg of total RNA extracted from 3 h prepupae of the (-57/+40) transgenic line were hybridized either with the lacZ probe or the Actin probe, as indicated. The migration of the RNA size markers is indicated on the right.