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. 1974 Aug;71(8):3078–3081. doi: 10.1073/pnas.71.8.3078

Free Ribosomal RNA Genes in the Macronucleus of Tetrahymena

Joseph G Gall 1
PMCID: PMC388624  PMID: 4528573

Abstract

In the macronucleus of the ciliated protozoan, Tetrahymena pyriformis GL, the genes coding for 17S and 25S rRNA exist as free, extrachromosomal molecules. About 90% of the molecules are linear with a molecular weight of 12.6 × 106. Most of the remainder are circles of the same size, or lariats (circles with tails). A few dimers and oligomers are found. The extrachromosomal rDNA of Tetrahymena represents a kind of gene amplification that may be common among primitive eukaryotes.

Keywords: gene amplification, repetitive DNA, electron microscopy of DNA, RNA·DNA hybridization, protozoa

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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