|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1993 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Maedin-Darby canine kidney (MDCK) cells, which received high multiplicity superinfections with a weakly cytolytic mutant of influenza A virus, could survive and be passaged stably, carrying the genes of the infected virus. PB1, PB2, PA,NP,HA,NA,M and NS genes was detected in the 25th passaged cells using polymerase chain reaction (PCR).
In the 8th passaged cells, cRNA and mRNA of M gene was detected. The quantitation of the viral NS gene persisting in these cultured cells using competive PCR revealed that the gene existed at a relatively constant level (approximately 10^5 to 10^6 copies per 8 x 10^6 cells) over a long range of cell generations without producing any detectable projeny virus, suggesting that the persisting NS gene was not silent, but was amplified and inherited to the daughter cells.