Sgs1 Helicase and Meiotic Recombination
Sgs1 Helicase and Meiotic Recombination
Meiotic nuclei from pachytene-stage mer3 and mer3 sgs1-C795 mutant cells, surface spread and probed with anti-Red1 (green) and anti-Zip (red) to illuminate chromosome axes and the central element of synaptonemal complex, respectively. Mer3 is a meiosis-specific helicase required for normal meiotic crossing-over and for homolog synapsis; Sgs1 is the budding yeast homolog of the mammalian BLM helicase, which has been suggested to have anti-recombination activity. Removal of the Sgs1 helicase domain in the sgs1-C795 mutant restores both crossover recombination and homolog synapsis (shown here) to mer3 mutants, as well as to other crossover and synapsis-defective mutants. This finding shows that the Sgs1 helicase is a potent anti-recombinator whose action is blocked by meiosis-specific chromosomal proteins.
To learn more, visit Michael Lichten, Ph.D. Laboratory of Biochemistry and Molecular Biology.
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Jessop L, Rockmill B, Roeder GS, Lichten M. 2006. Meiotic chromosome synapsis-promoting proteins antagonize the anti-crossover activity of Sgs1. PLoS Genet 2:e155.
PubMed Abstract
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