Occurrence of heat-dissociable ribosomal RNA in insects: the presence of three polynucleotide chains in 26 S RNA from cultured Aedes aegypti cells.

摘要: Abstract When RNA extracted from a mixture of cultured mosquito (Aedes aegypti) and hamster (BHK) cells is heated at 60 °C for five minutes the 26 S but not 28 BHK converted to 18 products. These products are separable each other or pre-existent on 2.4% acrylamide gels have molecular weights near 0.7 × 106. The large ribosomal insects belonging ten different orders shows similar conversion, although this property absent in two species aphid. A. aegypti dissociates over narrow temperature range. reaction equilibrium favours dissociation dependent ionic strength, showing 6 deg. C change Tm′ (the 50% dissociation) with tenfold salt concentration. Although Tm Drosophila melanogaster markedly different, reflecting difference base composition, was virtually same. High weight Escherichia coli, terminally labelled [3H]isonicotinic acid hydrazide. specific activities show presence one, three polynucleotide chains 23 S, RNA, respectively. contains small, heat-dissociable “IRNA” relative amount mobility that found cells.