Cytoplasmic ribonucleic acids with messenger characteristics in salivary gland cells of Chironomus tentans

摘要: Abstract Export of RNA from nuclei to cytoplasm was investigated in salivary gland cells the dipteran Chironomus tentans with injected radioactive precursors. extracted and isolated fixed by micromanipulation characterized gel electrophoresis Millipore filtration. Four kinds cytoplasmic were studied : ribosomal RNA, 4 S two types heterodisperse, messenger-like RNAs. One these, designated early has several characteristics messenger such as size distribution, lag time for appearance (30 min) a relatively short life. It is adsorbed filters contrast RNA. A second type heterogeneous late differentiated cell products being tissue specific long half largely filters. probable origin Balbiani rings (large, tissue-specific puffs). The differs most having much slower migration during electrophoresis. also longer time, three hours, appearance. Ribosomal stable They both enter after distinct intervals, 30 60 minutes about hours small component preceding large one. present data suggest that messengers pronounced differences intranuclear processing times lives co-exist these cells. results can provide an explanation previously observed relative accumulation certain gene nuclei. explain preponderance synthesis few (secretory proteins) which have genome where transcription distributed over number chromosome bands.