Plant small nuclear RNAs. Nucleolar U3 snRNA is present in plants: partial characterization

Abstract
Nuclei, isolated from a number of plant species by either of two independent, newly developed methods, regularly contained a common set of low‐molecular‐mass RNAs. Partial characterization of these RNAs, based on cell fractionation, polyacrylamide gel electrophoretic and chemical sequencing techniques, as well as comparison with literature data, revealed that, in addition to tRNA, 5S RNA and 5.8S RNA, plant nuclei contain two families of low‐molecular‐mass RNAs, that are counterparts of vertebrate U1 and U5 RNAs respectively, and three individual low‐molecular‐mass RNA species. One of these may be related to vertebrate U6 RNA. The two others are true eukaryotic U2 and U3 RNAs, respectively, on the basis of the following lines of evidence obtained from analyses of broad bean nuclear RNAs.