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
Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segre...Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segregation and promote genetic diversity of progenies.Crossover patterns are tightly controlled and exhibit three characteristics:obligatory crossover,crossover interference,and crossover homeostasis.Aberrant crossover patterns are the leading cause of infertility,miscarriage,and congenital disease.Crossover recombination occurs in the context of meiotic chromosomes,and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally.Meiotic chromosomes are organized in a loop-axis architecture.Diverse evidence shows that chromosome axis length determines crossover frequency.Interestingly,short chromosomes show different crossover patterns compared to long chromosomes.A high frequency of human embryos are aneuploid,primarily derived from female meiosis errors.Dramatically increased aneuploidy in older women is the well-known“maternal age effect.”However,a high frequency of aneuploidy also occurs in young women,derived from crossover maturation inefficiency in human females.In addition,frequency of human aneuploidy also shows other age-dependent alterations.Here,current advances in the understanding of these issues are reviewed,regulation of crossover patterns by meiotic chromosomes are discussed,and issues that remain to be investigated are suggested.展开更多
Meiosis generates gametes with half the parental chromosome complements,and thus is crucial for successful sexual reproduction.During meiotic prophase I,a series of specialized events occur to ensure correct paternal ...Meiosis generates gametes with half the parental chromosome complements,and thus is crucial for successful sexual reproduction.During meiotic prophase I,a series of specialized events occur to ensure correct paternal and maternal homologous chromosomes（homologs）segregation during anaphase I.They include recognition,alignment,pairing and synapsis of the homologs and meiotic recombination which provides a link between homologs.展开更多
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.
基金This work is supported by grants from the National Key R&D Program of China(2018YFC1003700,2018YFC1003400)National Natural Science Foundation of China(31671293,31801203,and 31890782).
文摘Repairing DNA double-strand breaks(DSBs)with homologous chromosomes as templates is the hallmark of meiosis.The critical outcome of meiotic homologous recombination is crossovers,which ensure faithful chromosome segregation and promote genetic diversity of progenies.Crossover patterns are tightly controlled and exhibit three characteristics:obligatory crossover,crossover interference,and crossover homeostasis.Aberrant crossover patterns are the leading cause of infertility,miscarriage,and congenital disease.Crossover recombination occurs in the context of meiotic chromosomes,and it is tightly integrated with and regulated by meiotic chromosome structure both locally and globally.Meiotic chromosomes are organized in a loop-axis architecture.Diverse evidence shows that chromosome axis length determines crossover frequency.Interestingly,short chromosomes show different crossover patterns compared to long chromosomes.A high frequency of human embryos are aneuploid,primarily derived from female meiosis errors.Dramatically increased aneuploidy in older women is the well-known“maternal age effect.”However,a high frequency of aneuploidy also occurs in young women,derived from crossover maturation inefficiency in human females.In addition,frequency of human aneuploidy also shows other age-dependent alterations.Here,current advances in the understanding of these issues are reviewed,regulation of crossover patterns by meiotic chromosomes are discussed,and issues that remain to be investigated are suggested.
基金supported by Shandong Provincial Natural Science Foundation(JQ201605)the National Natural Science Foundation of China(31671293,31771385)the Fundamental Research Funds of Shandong University
文摘Meiosis generates gametes with half the parental chromosome complements,and thus is crucial for successful sexual reproduction.During meiotic prophase I,a series of specialized events occur to ensure correct paternal and maternal homologous chromosomes（homologs）segregation during anaphase I.They include recognition,alignment,pairing and synapsis of the homologs and meiotic recombination which provides a link between homologs.
