What is balbiani ring ??
Answers
Answer:
Balbiani rings are exceptionally large puffs on the polytene chromosomes in the dipteran Chironomus tentans. These puffs are particularly well suited for studies of the structure of active genes and the synthesis and transport of specific RNA-protein (RNP) particles.
Explanation:
Answer:
Balbiani rings are sites of particularly active RNA synthesis on the polytene chromosomes of Chironomids. Three such sites occur on the fourth chromosome in the salivary glands of Chironomus tentans. The RNA products of two of them (BR1 and BR2) have molecular weights of over 10 × 10° Daltons and age thought to code salivary proteins, which include fractions of more than 5 × 105 Daltons. In order to obtain insight into the nature of their primary translation products, RNA was isolated from salivary glands and translated in a cell-free system from rabbit reticulocytes. Salivary gland RNA induces the synthesis of a set of polypeptides, having molecular weights of up to 5 × 105. Immunoprecipitation studies, using an antiserum directed against total saliva, indicate that the very large species synthesized in vitro are immunologically related to constituents of saliva. These data provide evidence to support the contention that the unusually large proteins present in saliva are primary products of translation and are most probably coded by Balbiani ring RNA.