An Association Between Globin Messenger RNA and 60S RNA Derived from Friend Leukemia Virus

The association between certain cellular RNAs and purified RNA tumor viruses prompted us to examine the possibility that specific host messenger RNAs might also be incorporated into RNA tumor viruses. Using a mouse cell line infected with Friend leukemia virus, T-3-Cl-2, which can be induced to accumulate mouse-globin messenger RNA, we show that mouse-globin messenger RNA sequences are present in viral particles purified from the culture medium of globin-producing cells. These globin messenger RNA sequences are absent from viral particles derived from T-3-Cl-2 cells that are not producing globin messenger RNA. Virus-associated globin messenger RNA sequences sediment in association with the 60S viral RNA complex as well as in free, 9S form. However, under mild denaturing conditions which result in the conversion of viral 60S RNA to 30S and smaller forms, all the globin sequences sediment as 9S RNA. Appropriate control experiments indicate that the virus-associated globin messenger RNA is resistant to degradation by exogenous ribonuclease; that exogenously added globin messenger RNA does not become associated with the 60S viral RNA complex; and that globin messenger RNA can be detected in virions derived from cells both induced for and constitutively synthesizing globin messenger RNA.