Abstract
The snPI [small nuclear polymerase I] RNA species are a recently described set of molecules whose sizes range from 5-10S. They can be labeled in vitro in isolated nuclei and are apparently formed by an RNA polymerase I type of activity. In contrast to ribosomal precursor RNA, the usual polymerase I product, they are not found in the nucleolus but rather are located in the nucleoplasm. The snPI RNA were found in all mammalian cell types studied [including mouse myeloma MOPC 315 cells, Friend erythroleukemia cells, 3T6 fibroblast cells, neuroblastoma cells, neoplastic fibroblast L cells, rat epithelial cells, human diploid fibroblast cells, HeLa S3 cervical carcinoma cells, Chinese hamster ovary cells, African green monkey kidney BSC-1 cells and gorilla fibroblast cells]. The spectrum seen in gel electrophoresis is unique to each animal species studied but is essentially the same in different cell types within a species. The differences in snPI patterns are quite large between even closely related species and are clearly distinguishable in gorilla and human cells.

This publication has 4 references indexed in Scilit: