Poly(A)-containing RNA in Tetrahymena pyriformis.

Poly(A)-containing RNAs with sedimentation coefficients in the range 10-45 S and 10-35 S (Mr 0.2-3.3 x 10(6) and 0.2-2.2 x 10(6) approximately) are present in the nucleus and cytoplasm of T. pyriformis respectively. The poly(A) segments present in both nuclear and cytoplasmic poly(A)-containing RNAs have a chain length of 80 - 150 nucleotides. Significant amounts of high-molecular-weight poly(A)-containing RNAs (35 S, Mr 2.2 x 10(6) are found in the post-polysomal fraction of the cytoplasm (messenger ribonucleoprotein particles?) and also in large polysomes. In order to exclude the possibility that these high-molecular-weight species are products of non-specific aggregation, RNA preparations were submitted to severe denaturing conditions before analysis and all electrophoreses were carried out in the presence of 95% (v/v) formamide.