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. 1974 Apr;71(4):1272–1276. doi: 10.1073/pnas.71.4.1272

Unequal Mitotic Sister Chromatid Exchange as the Mechanism of Ribosomal RNA Gene Magnification

Kenneth D Tartof 1
PMCID: PMC388208  PMID: 4208547

Abstract

It is hypothesized that magnification of the gene coding for ribosomal RNA occurs by unequal mitotic sister chromatid exchange on the basis of five different lines of evidence. These are: (1) rDNA magnification occurs in mitotically active germ cells; (2) decreases in rDNA redundancy can be genetically produced, a phenomenon termed reduction; (3) magnification and reduction events are reversible and reciprocal; (4) it is possible to generate bb+ and bb somatic bristle mosaics (bb mutants are partially deficient for rRNA genes); and (5) magnification of bb in a ring X chromosome is reduced. Implications of these results and the unequal sister exchange (USE) hypothesis are discussed.

Keywords: gene reduction, Drosophila melanogaster, bobbed mutants, gene expansion-contraction

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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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