We have compared the amount of DNA complementary to the 5 S, 5·8 S and 4 S RNAs in a strain of Saccharomyces cerevisiae monosomic for chromosome I and a related diploid. The monosomic strain contains approximately 25% less DNA complementary to both 5 S and 5·8 S RNA than the diploid. The amount of DNA complementary to 4 S RNA is the same in both strains. These results indicate that the same relative proportions of the 5 S RNA genes, and the 5·8 S genes as well as the 18 S and 26 S RNA genes are present on chromosome I. Moreover, we have observed that the monosomic strain reverted to normal levels of DNA complementary to 5 S, 5·8 S, 18 S and 26 S RNA when continuously cultured for several months even though the strain remained monosomic for chromosome I by genetic criteria. This co-ordinate recovery in gene number is consistent with the close association of the 5 S, 5·8 S, 18 S and 26 S ribosomal RNA genes in yeast.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology