Figure 4.

RNase protection assays to quantitate hGH RNA levels in transgenic mouse tissues. RNase protection assays were carried out as described. (A) Assays on adult skin. First lane shows migration of aliquot of antisense RNAs before RNase digestion. Other lanes show migration of radiolabeled antisense probes after incubation with skin RNAs and RNase treatment. Note the reduction in size for both mGAPDH (open arrowhead at right) and hGH (filled arrowhead at right) RNAs, reflective of digestion of the random (i.e., nonhybridizing) sequences in each of the two probes. This serves as an internal control for the RNase. (B) Assays on tissues. Lanes show protected radiolabeled cRNAs after hybridization with 9-month-old transgenic tissue RNAs and subsequent RNase treatment. Last lane shows migration of HinfI-digested pSP64 plasmid DNAs, end-labeled and used as molecular mass markers. (Note, the specific activity of the mGAPDH probe was higher in A versus B.)