Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability.
During meiosis, the Msh4-Msh5 complex is thought to stabilize single-end invasion intermediates that form during early stages of recombination and subsequently bind to Holliday junctions to facilitate crossover formation. To analyze Msh4-Msh5 function, we mutagenized 57 residues in Saccharomyces cer...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2010-08-01
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| Series: | PLoS Genetics |
| Online Access: | http://europepmc.org/articles/PMC2928781?pdf=render |
| _version_ | 1828413620269088768 |
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| author | K T Nishant Cheng Chen Miki Shinohara Akira Shinohara Eric Alani |
| author_facet | K T Nishant Cheng Chen Miki Shinohara Akira Shinohara Eric Alani |
| author_sort | K T Nishant |
| collection | DOAJ |
| description | During meiosis, the Msh4-Msh5 complex is thought to stabilize single-end invasion intermediates that form during early stages of recombination and subsequently bind to Holliday junctions to facilitate crossover formation. To analyze Msh4-Msh5 function, we mutagenized 57 residues in Saccharomyces cerevisiae Msh4 and Msh5 that are either conserved across all Msh4/5 family members or are specific to Msh4 and Msh5. The Msh5 subunit appeared more sensitive to mutagenesis. We identified msh4 and msh5 threshold (msh4/5-t) mutants that showed wild-type spore viability and crossover interference but displayed, compared to wild-type, up to a two-fold decrease in crossing over on large and medium sized chromosomes (XV, VII, VIII). Crossing over on a small chromosome, however, approached wild-type levels. The msh4/5-t mutants also displayed synaptonemal complex assembly defects. A triple mutant containing a msh4/5-t allele and mutations that decreased meiotic double-strand break levels (spo11-HA) and crossover interference (pch2Δ) showed synergistic defects in spore viability. Together these results indicate that the baker's yeast meiotic cell does not require the ∼90 crossovers maintained by crossover homeostasis to form viable spores. They also show that Pch2-mediated crossover interference is important to maintain meiotic viability when crossovers become limiting. |
| first_indexed | 2024-12-10T13:11:05Z |
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| issn | 1553-7390 1553-7404 |
| language | English |
| last_indexed | 2024-12-10T13:11:05Z |
| publishDate | 2010-08-01 |
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| spelling | doaj.art-b843df5046904d04beb8f9795c6017ae2022-12-22T01:47:40ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042010-08-016810.1371/journal.pgen.1001083Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability.K T NishantCheng ChenMiki ShinoharaAkira ShinoharaEric AlaniDuring meiosis, the Msh4-Msh5 complex is thought to stabilize single-end invasion intermediates that form during early stages of recombination and subsequently bind to Holliday junctions to facilitate crossover formation. To analyze Msh4-Msh5 function, we mutagenized 57 residues in Saccharomyces cerevisiae Msh4 and Msh5 that are either conserved across all Msh4/5 family members or are specific to Msh4 and Msh5. The Msh5 subunit appeared more sensitive to mutagenesis. We identified msh4 and msh5 threshold (msh4/5-t) mutants that showed wild-type spore viability and crossover interference but displayed, compared to wild-type, up to a two-fold decrease in crossing over on large and medium sized chromosomes (XV, VII, VIII). Crossing over on a small chromosome, however, approached wild-type levels. The msh4/5-t mutants also displayed synaptonemal complex assembly defects. A triple mutant containing a msh4/5-t allele and mutations that decreased meiotic double-strand break levels (spo11-HA) and crossover interference (pch2Δ) showed synergistic defects in spore viability. Together these results indicate that the baker's yeast meiotic cell does not require the ∼90 crossovers maintained by crossover homeostasis to form viable spores. They also show that Pch2-mediated crossover interference is important to maintain meiotic viability when crossovers become limiting.http://europepmc.org/articles/PMC2928781?pdf=render |
| spellingShingle | K T Nishant Cheng Chen Miki Shinohara Akira Shinohara Eric Alani Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. PLoS Genetics |
| title | Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. |
| title_full | Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. |
| title_fullStr | Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. |
| title_full_unstemmed | Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. |
| title_short | Genetic analysis of baker's yeast Msh4-Msh5 reveals a threshold crossover level for meiotic viability. |
| title_sort | genetic analysis of baker s yeast msh4 msh5 reveals a threshold crossover level for meiotic viability |
| url | http://europepmc.org/articles/PMC2928781?pdf=render |
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