The Structure and Evolution of Ribosomal and 5 S DNAs in Xenopus laevis and Xenopus mulleri (original) (raw)

1. Donald D. Brown and
2. Kazunori Sugimoto
3. Carnegie Institution of Washington, Department of Embryology, Baltimore, Maryland 21210

Excerpt

The isolation of genes of known structure has provided information on their arrangement and evolution. This analysis is most advanced for the genes for ribosomal RNAs due to the ease with which these RNAs can be purified for use in hybridization assays of the genes. In addition, the genes are present in many copies in the genome and have unusual physical and chemical characteristics that have facilitated their purification (Wallace and Birnstiel, 1966; Brown and Weber, 1968a).

The genes coding for the structure of the 18 S and 28 S ribosomal RNAs (rDNA) (Birnstiel et al., 1966; Brown and Dawid, 1968; Brown et al., 1972) and those for the low molecular weight 5 S ribosomal RNA (5 S DNA) (Brown et al., 1971; Brown and Sugimoto, 1973) have been purified from the DNA of Xenopus laevis and Xenopus mulleri. These genes are highly repetitive and occur in one or more...