FIG. 5.

Analysis of viral and soluble receptor RNA levels in tissues of chickens infected with RCASBP(B). The figure shows autoradiograms of 6% polyacrylamide–7.6 M urea gels used to separate the protected RNA probe fragments produced in an RNase protection assay with RNA from a bird infected with RCASBP(B)stva or RCASBP(B)stva-mIgG. RNA was prepared from liver (L), heart (H), spleen (S), bursa (B), thymus (T), kidney (K), and muscle (M) tissues of each bird. RNA from DF-1 cells infected with the appropriate virus was included as a positive control (+). RNA from the bursa of an uninfected bird was the negative control (−). ALV(B) env RNA protects a 467-nucleotide fragment from the 522-nucleotide ³²P-labeled full-length probe [env(B)]; stva RNA protects a 388-nucleotide fragment from the 498-nucleotide probe (stva); and stva-mIgG RNA protects a 363-nucleotide fragment from the 423-nucleotide probe (stva-mIgG). Each assay mixture contained a chicken GAPDH probe as a control for RNA quality and quantity. GAPDH RNA protects a 200-nucleotide fragment from the 279-nucleotide GAPDH probe.