Rna in Single Identified Neurons of Aplysia1

Abstract —An investigation of the types of RNA present in the whole abdominal ganglia of Aplysia and in single identified neurons was made. Because of the long in vitro functioning of the ganglion and large size of the neurons, adequate labelled precursor was incorporated to allow gel electrophoretic or sedimentation analysis of RNA isolated from a single nucleus or from cytoplasm. When labelled RNA is analysed a number of distinct peaks are found. Most of these are related to rRNA. In an effort to discern possible precursor‐product relations and localization of these RNA species, RNA from the nucleus and the cytoplasm of neuron R2 was analysed after varying lengths of labelling time with tritiated precursors, in some cases followed by incubation with actinomycin. The results support the notion of a large transcribed precursor which is subsequently processed to form finished rRNA. Differences in rate of rRNA maturation among neurons are indicated and a previously unreported 14 S molecule is described.