RNAi and heterochromatin repress centromeric meiotic recombination
During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essentia...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 107; no. 19; pp. 8701 - 8705 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
11.05.2010
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes, is essential in most species for proper homologue segregation. Nevertheless, recombination is repressed specifically in and around the centromeres of chromosomes, apparently because rare centromeric (or pericentromeric) recombination events, when they do occur, can disrupt proper segregation and lead to genetic disabilities, including birth defects. The basis by which centromeric meiotic recombination is repressed has been largely unknown. We report here that, in fission yeast, RNAi functions and Clr4-Rik1 (histone H3 lysine 9 methyltransferase) are required for repression of centromeric recombination. Surprisingly, one mutant derepressed for recombination in the heterochromatic mating-type region during meiosis and several mutants derepressed for centromeric gene expression during mitotic growth are not derepressed for centromeric recombination during meiosis. These results reveal a complex relation between types of repression by heterochromatin. Our results also reveal a previously undemonstrated role for RNAi and heterochromatin in the repression of meiotic centromeric recombination and, potentially, in the prevention of birth defects by maintenance of proper chromosome segregation during meiosis. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author contributions: C.E., E.C.H., N.P., L.H., J.L.G., G.T., and G.R.S. designed research; C.E., E.C.H., N.P., L.H., J.L.G., and G.R.S. performed research; C.E., E.C.H., N.P., L.H., J.L.G., G.T., and G.R.S. contributed new reagents/analytic tools; C.E., E.C.H., N.P., L.H., J.L.G., G.T., and G.R.S. analyzed data; and C.E., E.C.H., N.P., L.H., G.T., and G.R.S. wrote the paper. Edited* by Paul Nurse, The Rockefeller University, New York, NY, and approved April 2, 2010 (received for review December 9, 2009) 1Present address: Feinberg School of Medicine, Northwestern University, Evanston, IL 60208. |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.0914160107 |