The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the ...The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the irr1-1 mutation (F658G) severely affected meiosis. The irr1 1/IRR1 cells were entering meiosis before having completed mitotic cell division. Using meiotic two-hybrid assay and co-immunoprecipitation we show that in cells arrested in pachytene due to a lack of a gene-regulatory factor Ndt80, the Irr1 protein interacts with Rec8p and the irr1-1 mutation abolishes this interaction. These findings indicate an important role of Irr1p in early stages of meiosis.展开更多
Objective:This study aimed to explore the relationship between cohesin subunit REC8 reduction and meiosis chromosome segregation errors in the ovary.Methods:Rec8^(+/-)mice were generated using CRIPSR/Cas9 gene editing...Objective:This study aimed to explore the relationship between cohesin subunit REC8 reduction and meiosis chromosome segregation errors in the ovary.Methods:Rec8^(+/-)mice were generated using CRIPSR/Cas9 gene editing.The association between age and REC8 expression levels in the ovary was determined by Western blotting.Chromosome segregation errors were investigated by immunofluorescence imaging of superovulated oocytes.Wild-type andRec8^(+/-)female mice at 5,8,20,36,and 40 weeks were used to evaluate ovarian reserve by ovarian clearing and immunolabeling.Results:Ovary REC8 expression levels gradually decreased with age,while chromosome segregation errors increased with age.Segregation errors were more common inRec8^(+/-)mice,suggesting an association with REC8 expression.The ovarian reserve capacity decreased significantly with age.The ovarian reserve inRec8^(+/-)mice was inferior to that of age-matched wild-type mice,indicating important roles of age and REC8 levels in the ovarian reserve.Conclusions:REC8 reduction has an age-cumulative effect on meiotic chromosome segregation errors in mouse ovaries.Rec8 haploinsufficiency poses a major challenge in generating normal and reproductive oocytes in aging mice.展开更多
Crossover recombination is a hallmark of meiosis that holds the paternal and maternal chromosomes(homologs)together for their faithful segregation,while promoting genetic diversity of the progeny.The pattern of crosso...Crossover recombination is a hallmark of meiosis that holds the paternal and maternal chromosomes(homologs)together for their faithful segregation,while promoting genetic diversity of the progeny.The pattern of crossover is mainly controlled by the architecture of the meiotic chromosomes.Environmental factors,especially temperature,also play an important role in modulating crossovers.However,it is unclear how temperature affects crossovers.Here,we examined the distribution of budding yeast axis components(Red1,Hop1,and Rec8)and the crossover-associated Zip3 foci in detail at different temperatures,and found that both increased and decreased temperatures result in shorter meiotic chromosome axes and more crossovers.Further investigations showed that temperature changes coordinately enhanced the hyperabundant accumulation of Hop1 and Red1 on chromosomes and the number of Zip3 foci.Most importantly,temperature-induced changes in the distribution of axis proteins and Zip3 foci depend on changes in DNA negative supercoils.These results suggest that yeast meiosis senses temperature changes by increasing the level of negative supercoils to increase crossovers and modulate chromosome organization.These findings provide a new perspective on understanding the effect and mechanism of temperature on meiotic recombination and chromosome organization,with important implications for evolution and breeding.展开更多
基金supported in part by the Ministry of Science and Higher Education,grants 0038/P01/2009/36 and 4568/B/P01/2010/38.
文摘The meiotic cohesin complex of S. cerevisiae shares with the mitotic one the Irr1/Scc3, Smc1, and Smc3 subunits, while the meiosis-specific subunit Rec8 replaces mitotic subunit Scc1/Mcd1. We noticed earlier that the irr1-1 mutation (F658G) severely affected meiosis. The irr1 1/IRR1 cells were entering meiosis before having completed mitotic cell division. Using meiotic two-hybrid assay and co-immunoprecipitation we show that in cells arrested in pachytene due to a lack of a gene-regulatory factor Ndt80, the Irr1 protein interacts with Rec8p and the irr1-1 mutation abolishes this interaction. These findings indicate an important role of Irr1p in early stages of meiosis.
基金Shanghai Municipal Science and Technology Major Project(2017 SHZDZX01)。
文摘Objective:This study aimed to explore the relationship between cohesin subunit REC8 reduction and meiosis chromosome segregation errors in the ovary.Methods:Rec8^(+/-)mice were generated using CRIPSR/Cas9 gene editing.The association between age and REC8 expression levels in the ovary was determined by Western blotting.Chromosome segregation errors were investigated by immunofluorescence imaging of superovulated oocytes.Wild-type andRec8^(+/-)female mice at 5,8,20,36,and 40 weeks were used to evaluate ovarian reserve by ovarian clearing and immunolabeling.Results:Ovary REC8 expression levels gradually decreased with age,while chromosome segregation errors increased with age.Segregation errors were more common inRec8^(+/-)mice,suggesting an association with REC8 expression.The ovarian reserve capacity decreased significantly with age.The ovarian reserve inRec8^(+/-)mice was inferior to that of age-matched wild-type mice,indicating important roles of age and REC8 levels in the ovarian reserve.Conclusions:REC8 reduction has an age-cumulative effect on meiotic chromosome segregation errors in mouse ovaries.Rec8 haploinsufficiency poses a major challenge in generating normal and reproductive oocytes in aging mice.
基金funded by the National Natural Science Foundation of China(32225015,32070837,32370907,32070575,32270895)the National Key Research and Developmental Program of China(2022YFC2702602,2021YFC2700103)the Taishan Scholars Program of Shandong Province(tstp20231256).
文摘Crossover recombination is a hallmark of meiosis that holds the paternal and maternal chromosomes(homologs)together for their faithful segregation,while promoting genetic diversity of the progeny.The pattern of crossover is mainly controlled by the architecture of the meiotic chromosomes.Environmental factors,especially temperature,also play an important role in modulating crossovers.However,it is unclear how temperature affects crossovers.Here,we examined the distribution of budding yeast axis components(Red1,Hop1,and Rec8)and the crossover-associated Zip3 foci in detail at different temperatures,and found that both increased and decreased temperatures result in shorter meiotic chromosome axes and more crossovers.Further investigations showed that temperature changes coordinately enhanced the hyperabundant accumulation of Hop1 and Red1 on chromosomes and the number of Zip3 foci.Most importantly,temperature-induced changes in the distribution of axis proteins and Zip3 foci depend on changes in DNA negative supercoils.These results suggest that yeast meiosis senses temperature changes by increasing the level of negative supercoils to increase crossovers and modulate chromosome organization.These findings provide a new perspective on understanding the effect and mechanism of temperature on meiotic recombination and chromosome organization,with important implications for evolution and breeding.
