Productive and abortive infection of L cells by fowl plague virus (FPV): comparison of in vivo and in vitro translation products of the virus mRNAs.

The abortive infection of L cells by the Dobson strain of fowl plague virus (FPV) and the productive infection by a mammalian cell-adapted mutant have been compared. The mRNA population during the abortive cycle is characterized by a lower production compared to the productive system of mRNA 7 (which codes for the M polypeptide) early in the cycle, and a lower production of mRNAs 4, 6 and 7 (which code for HA, NA and M) late in the cycle. Differences in the amounts of the corresponding polypeptides can also be detected when these mRNA populations are used to programme a wheat germ cell-free system. However, analysis of the polypeptides synthesized in vivo by the two viruses show that equivalent amounts of all virus polypeptides are synthesized during the productive and the abortive cycles. Possible reasons for differences between in vivo and in vitro translation of the virus mRNAs during the abortive cycle are discussed.