Demonstration of Balbiani ring RNA sequences in polysomes.

Open Access
Publisher Website
Google Scholar
Abstract
A polysome extract from salivary glands of Chironomus tentans was sedimented in a 15-60% sucrose gradient. Fractions from the heavy polysome region (1000-2000S) and fractions from the light polysome region (200-1000S) were pooled separately, and the long-term labeled RNA was released by Sarkosyl/pronase and analyzed by in situ hybridization. BR 1 [balbani ring] and BR 2 sequences were apparently present in the heavy and the light polysome regions of the sucrose gradient. From control experiments with EDTA-treated extracts, most of the recorded BR 1 and BR 2 sequences were in fact located in polysomes. The finding that BR products enter polysomes suggests that they act as messenger RNA molecules. Chromosome puffs may represent active genes.