Poly(A)-containing RNA in embryonic chick tissues

Abstract

Cytoplasmic and nuclear RNA is prepared from chick embryo skin, muscle and brain at 13 days of incubation. The concentration and labelling of RNA is measured after oligo(dT) chromatography. Skin, muscle and brain contain respectively 4.8, 3.6 and 5.6% cytoplasmic RNA with a poly(A) segment. The corresponding figures for nuclear poly(A)-containing RNA are 13, 16 and 9.4%. In skin, incorporation of [3H]uridine in RNA lacking poly(A) exceeds the rate of incorporation into muscle and brain RNA by about 2.5- and 5-fold, respectively. By contrast, no such large differences in rates of incorporation between the tissues are observed with poly(A)-containing RNA.