FIG. 2.
Immunoblot analysis of FFV Gag and Pol and chimeric Bet-E protein expression of vectors pCF-7, pCF-FCV23 (subclones 13 and 15), pCF-FCV23-U3 (subclones 25 and 27), pCF-FCV24 (subclones 19 and 23), and pCF-FCV24-U3 (subclones 20 and 24). CRFK cells were lysed 3 days after transfection with the vector genomes, and cellular extracts were analyzed by immunoblotting. In panel A, cat serum 8014 detecting p127Pol, p70Pol, p52Gag, and p48Gag was used. The positions of molecular mass markers are shown in kilodaltons in the left margin. The names of the proteins detected are shown in the right margin. The Bet-E fusion proteins Bet-E23 (47 kDa) and Bet-E24 (55 kDa) were detected with hyperimmune sera directed against bacterially expressed FFV Bet (B) and FCV capsid (C). The Bet antiserum also reacted with the authentic Bet expressed from control vector pCF-7 (B). In panel D, extracts of CRFK cells transfected with vectors pCF-FCV23, pCF-FCV24, pCF-FCV14, and pCF-7 were analyzed by immunoblotting with FCV isolate KS20-specific cat antiserum 746 and the heterologous KS100/2-specific serum 736. As expected, only the KS20-specific serum detected the different Bet-E fusion proteins.