[Poly(A) sequences associated with rabies virus mRNA (author's transl)].

Polyadenylate sequences have been found in numerous RNA with messenger function, and in several viruses in which the genome is its own messenger. With rabies virus we observed a fixation of viral RNA on Sepharose poly(U) column in the mRNA region (8-25S) and in the double stranded RNA region (25-35S). These percentages of fixation are very low compared to those of VSV in the same regions, but they are significant compared to the uninfected cells and to Lumbo RNA fixation. In order to determine the nature of the RNA bound to poly(U)-sepharose, fractions of the region 8-25S and 25-35S obtained after elution with formamide were centrifuged through a sucrose gradient. We found in the 8-25S region an RNA profile which was identical to the initial profile of this region. In contrast, the 25-35S region exhibited a heterogenous profile which looked like the total virus RNA profile obtained from infected cells. This may be due to the presence of double-stranded RNA in this region which is partially adsorbed on poly(U) and denatured by formamide in RNA molecules of genome and mRNA size. We conclude from our results that the low percentage of fixation of rabies mRNA on poly(U)-sepharose columns could mean either that a small number of molecules are polyadenylated or that a large number exhibit poly(A) tracts too short to be retained by the poly(U).