Polyacrylamide gel mapping of chicken tRNA: comparison of polysome-bound and whole-cell tRNA from normal and avian sarcoma virus-infected chicken embryo fibroblasts

Relative content of isoaccepting tRNAs for glycine and proline in avian tendon cells with different rates of procollagen synthesis

The relative amounts of iso-tRNAsGly and iso-tRNAsPro existing in chick embryo tendon are indicative of a specialization of the tRNA population for collagen synthesis. These amounts are not modified (i) in primary avian tendon (PAT) cells in culture for which the procollagen production varies from about 10% of total protein synthesis to 60% and (ii) in tendons from immature chicks, which show a 3-fold decrease of procollagen production with increasing age. The characteristic tRNA pattern was not maintained in cells which had lost the ability to make high levels of collagen as observed in the cases of: (i) PAT cells reaching confluency; (ii) virus-transformed PAT cells and (iii) tendon from adult chick. Our data are consistent with the idea that tendon tRNA specialization for collagen synthesis is a differentiation feature independent of the expression level of the collagenic function but related to its maintenance.

Distribution of isoaccepting tRNAs and codons for proline and glycine in collagenous and noncollagenous chicken tissues

The relation between codon usage and tRNA content for proline and glycine, the major constituents of collagen, was studied in two tissues: the magnum of laying hen oviduct and the leg tendons of chick embryo where collagen is produced. Although the relative contents of tRNA(GCCGly) and tRNA(IGGPro) in tendons, as compared to magnum indicate a specialization of the tRNA population for collagen synthesis, the distribution of the preponderant codons in collagen mRNA is correlated but at a lesser extent to that of their cognate tRNAs.

Accumulation and specific cleavage of 5S RNA in the isthmus of laying hen oviduct. Evidence for three chicken 5S RNA

RNA extracts from the isthmus of laying hen oviduct contain truncated 5S RNA molecules that were found to be shorter at their 5' terminus as compared to native 5S RNA I and II. Moreover one of the truncated species differs from 5S RNA I by the absence of the 3' end nucleotide. The truncated forms increase of about 70% the total 5S RNA (intact + truncated) in the isthmus, as compared to the other studied tissues. Furthermore 5S RNA I is heterogeneous: 25% have A instead of U at the 3' end, and some evidence was obtained for the existence of two 5S RNA I conformers.