Correlated changes of Balbiani ring expansion and secretory protein synthesis in larval salivary glands of Chironomus tentans.

Salivary glands of various stages of the last larval instar of Chironomus tentans were quantitatively analyzed with respect to the expansion of their Balbiani rings (B1, B2, B3) by a fast green staining procedure as well as to the rate of synthesis of their secretory proteins (S1, S2, S3) by a scintillation counting procedure of electrophoretic fractions. The extent of expansion of B1, B2 and B3 correlates positively with the rate of synthesis of S3, S2 and S1, respectively. With B1 and S3 these parameters undergo a parallel and developmentally specific change being rather depressed in intermolt, and particularly in diapausing animals.