Studies on RNA in goldfish brain. I. Isolation and in vivo labeling

Abstract

Methods are presented for the isolation of high molecular weight RNA from nuclear and cytoplasmic fractions of goldfish brain following intracranial injection of [5- 3 H]uridine. Nuclear RNA is labeled first and is followed by labeling of cytoplasmic RNA. The pattern of labeling in the nuclear fraction reflects the formation of broadly distributed RNA species some of which sediment more rapidly than 28S RNA. Radioactivity appears later in the cytoplasm and sediments heterogeneously from 4S to > 50S. Evidence is presented for the presence of a 45S ribosomal RNA precursor and for messenger RNA in the goldfish brain.