Alterations in SVT2 cell transfer RNAs in response to cell density and serum type.

The chromatographic elution profiles of tRNA-A sn, tRNA-A sp, tRNA-H is and tRNA-T y r from SV40-transformed BALB-3T3 cells grown in fetal calf serum or cald serum-supplemented media have been examined. The relative proportions of certain of the isoaccepting species of these four tRNAs are altered in a similar fashion depending on the serum type. It is suggested that the elution profile alterations reflect the extent of modifications of a specific G residue to the minor nucleoside Q, and that this process differs between untransformed and transformed cells. In addition, cell density appears to influence the Q content of these tRNAs, though other density-dependent tRNA modifications also appear to occur.