Different RNA Fractions during Cell Growth and Synchronous Division in Mass Cultures of Tetrahymena Pyriformis

Abstract

Abstract The cellular divisions in mass cultures of the ciliate Tetrahymena pyriformis GL were synchronized through heat treatment. At all stages of the cell cycle were found two metabolically and chemically distinct classes of RNA fractionated by phenol. The fraction left behind in the phenol was poorer in guanylic acid and incorporated radioactive phosphorus more rapidly than the other that had been released in the phenol aqueous phase. The RNA fractions left behind in phenol decreased during heat treatment but showed a rapid increase prior to division. The RNA of the aqueous phase, on the other hand, rose almost proportionally to the cell size up to division. The RNA fraction released in the aqueous phase was chromatographed on Ecteola cellulose ion‐exhange columns.