Originally published as Genetics Published Articles Ahead of Print on March 4, 2007.

Genetics, Vol. 176, 53-62, May 2007, Copyright © 2007
doi:10.1534/genetics.107.070367

Meiotic Recombination in Drosophila Msh6 Mutants Yields Discontinuous Gene Conversion Tracts

* Curriculum in Genetics and Molecular Biology and {dagger} Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599

2 Corresponding author: Department of Biology, CB 3280, 303 Fordham Hall, University of North Carolina, Chapel Hill, NC 27599-3280.
E-mail: sekelsky{at}unc.edu

Crossovers (COs) generated through meiotic recombination are important for the correct segregation of homologous chromosomes during meiosis. Several models describing the molecular mechanism of meiotic recombination have been proposed. These models differ in the arrangement of heteroduplex DNA (hDNA) in recombination intermediates. Heterologies in hDNA are usually repaired prior to the recovery of recombination products, thereby obscuring information about the arrangement of hDNA. To examine hDNA in meiotic recombination in Drosophila melanogaster, we sought to block hDNA repair by conducting recombination assays in a mutant defective in mismatch repair (MMR). We generated mutations in the MMR gene Msh6 and analyzed recombination between highly polymorphic homologous chromosomes. We found that hDNA often goes unrepaired during meiotic recombination in an Msh6 mutant, leading to high levels of postmeiotic segregation; however, hDNA and gene conversion tracts are frequently discontinuous, with multiple transitions between gene conversion, restoration, and unrepaired hDNA. We suggest that these discontinuities reflect the activity of a short-patch repair system that operates when canonical MMR is defective.




This article has been cited by other articles:


Home page
GeneticsHome page
A. Svetlanov, F. Baudat, P. E. Cohen, and B. de Massy
Distinct Functions of MLH3 at Recombination Hot Spots in the Mouse
Genetics, April 1, 2008; 178(4): 1937 - 1945.
[Abstract] [Full Text] [PDF]


Home page
Mol. Cell. Biol.Home page
J. A. Smith, L. A. Bannister, V. Bhattacharjee, Y. Wang, B. C. Waldman, and A. S. Waldman
Accurate Homologous Recombination Is a Prominent Double-Strand Break Repair Pathway in Mammalian Chromosomes and Is Modulated by Mismatch Repair Protein Msh2
Mol. Cell. Biol., November 15, 2007; 27(22): 7816 - 7827.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
S. J. Radford, S. McMahan, H. L. Blanton, and J. Sekelsky
Heteroduplex DNA in Meiotic Recombination in Drosophila mei-9 Mutants
Genetics, May 1, 2007; 176(1): 63 - 72.
[Abstract] [Full Text] [PDF]