RELATION OF CELL TYPE AND CELL DENSITY IN TISSUE-CULTURE TO ISOACCEPTING SPECTRA OF NUCLEOSIDE Q CONTAINING TRANSFER RNAS-TRANSFER RNATYR, TRANSFER RNAHIS, TRANSFER RNAASN AND TRANSFER RNAASP

An examination, using reversed-phase chromatograph and cyanogen bromide treatment, of tRNATYr, tRNAHis, tRNAAsn, and tRNAAsp from SV40-transformed mouse fibroblasts grown to different cell densities, untransformed cells grown to confluence, and mouse liver indicates that: (1) The tissue cultured mouse fibroblasts examined here are hypomodified with respect to nucleoside Q, while liver tRNA is almost completely modified with respect to Q. (2) Cell density and/or proliferative state do not present as major variables in controlling the expression of Q in the present system. (3) SV40 virus transformation is not a major variable controlling the expression of Q in the present system. The present results support previous use of cyanogen bromide effected shifts in chromatographic elution as an assay for nucleoside Q. © 1978 Information Retrieval Limited.