%0 Journal Article %A Kohase, Masayoshi %A Kohno, Seiya %T Temperature-sensitive Mutants of Newcastle Disease Virus Affecting Interferon Induction %D 1983 %J Journal of General Virology, %V 64 %N 7 %P 1469-1474 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-64-7-1469 %K IFN induction %K NDV mutants %K u.v. target size %K primary transcription %I Microbiology Society, %X SUMMARY Temperature-sensitive (ts) mutants of Newcastle disease virus (NDV) were isolated and studied for interferon (IFN) induction in primary chick embryo (CE) cells. At the non-permissive temperature (41 °C), there was no viral RNA synthesis or IFN induction by u.v.-treated virions except for ts-3 (RNA+), which did synthesize RNA at 41 °C, and whose u.v.-treated virions did induce IFN at this temperature. Another mutant (ts-4) induced IFN without irradiation, at the permissive temperature (37 °C). The minimum u.v. target size for IFN inducibility was unaffected by the mutation and corresponded to about 5% of the genome required for the expression of infectivity. These results support the hypothesis that the appearance of NDV RNA immediately after infection (primary transcription) plays a key role in IFN induction. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-64-7-1469