[Nuclear apparatus and differentiation of salivary glands of larvae of Drosophila virilis. 1. Change in DNA and RNA content in different cell structures at the stage of secretion formation].

Changes in the content of DNA, RNA and secretion products have been studied in chromosomes, nucleoli and cytoplasm of the salivary gland cells in the III instar larvae D. virilis. The DNA content doubles twice: 20--30 and 30--40 hrs after the second moult. The first doubling is followed by the intensive formation of secretion products. The RNA content increases from 30 hrs in chromosomes and twice in nucleoli: from the beginning of II instar till 20 and from 40 till 50 hrs. The maximum RNA content is registered at 50 hrs in chromosomes and nucleoli and between 50 and 70 hrs in cytoplasm.