RNA synthesis in rooster liver

Abstract

RNA extracted from rooster liver by differential thermal phenol extraction was characterized by sedimentation patterns, base composition and incorporation studies. Essentially all cellular RNA could be extracted in distinct classes by subsequent treatment at cold-room temperature, 45°, 65° and with sodium dodecyl sulphate at 65°. In the low temperature extract only (cytoplasmic) transfer and ribosomal RNA could be detected. The 45° fraction probably contains nuclear ribosomal RNA and rRNA precursors. The 65° and 65°—sodium dodecyl sulphate—extracted RNA contain heterogeneously labeled RNA and a distinct 16–18-S fraction. From the latter extract DNA could be effectively removed by deoxyribonuclease treatment. Though several fractions show differences in short-time and homogeneously labeled base composition, no unlabeled fraction with DNA-like base composition was found. Estradiol doses inducing major changes in protein synthesis do not give rise to specific changes in any of the RNA fractions studied, although the incorporation of radioactive precursors in general is enhanced.