Work

Evolution of an MCM Complex in Flies That Promotes Meiotic Crossovers by Blocking BLM Helicase

Year: 2012

Type: article

Abstract: Generation of meiotic crossovers in many eukaryotes requires the elimination of anti-crossover activities by using the Msh4-Msh5 heterodimer to block helicases. Msh4 and Msh5 have been lost from the flies Drosophila and Glossina, but we identified a complex of minichromosome maintenance (MCM) proteins that functionally replace Msh4-Msh5. We found that REC, an ortholog of MCM8 that evolved under strong positive selection in flies, interacts with MEI-217 and MEI-218, which arose from a previously undescribed metazoan-specific MCM protein. Meiotic crossovers were reduced in Drosophila rec, mei-217, and mei-218 mutants; however, removal of the Bloom syndrome helicase (BLM) ortholog restored crossovers. Thus, MCMs were co-opted into a novel complex that replaced the meiotic pro-crossover function of Msh4-Msh5 in flies.

Source: Science

DOI: 10.1126/science.1228190

Authors: Kathryn P. Kohl, Corbin D. Jones, Jeff Sekelsky

Institution: University of North Carolina at Chapel Hill

Language: English

Topic: DNA Repair Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: National Science Foundation, National Institutes of Health, National Institute of General Medical Sciences

Awards: G3080255316, NRSA in Genetics, G573482977, An Integrative Analysis of Gene Conversion, Meiotic Recombination in Drosophila