In solving many-objective optimization problems(MaO Ps),existing nondominated sorting-based multi-objective evolutionary algorithms suffer from the fast loss of selection pressure.Most candidate solutions become nondo...In solving many-objective optimization problems(MaO Ps),existing nondominated sorting-based multi-objective evolutionary algorithms suffer from the fast loss of selection pressure.Most candidate solutions become nondominated during the evolutionary process,thus leading to the failure of producing offspring toward Pareto-optimal front with diversity.Can we find a more effective way to select nondominated solutions and resolve this issue?To answer this critical question,this work proposes to evolve solutions through line complex rather than solution points in Euclidean space.First,Plücker coordinates are used to project solution points to line complex composed of position vectors and momentum ones.Besides position vectors of the solution points,momentum vectors are used to extend the comparability of nondominated solutions and enhance selection pressure.Then,a new distance function designed for high-dimensional space is proposed to replace Euclidean distance as a more effective distancebased estimator.Based on them,a novel many-objective evolutionary algorithm(MaOEA)is proposed by integrating a line complex-based environmental selection strategy into the NSGAⅢframework.The proposed algorithm is compared with the state of the art on widely used benchmark problems with up to 15 objectives.Experimental results demonstrate its superior competitiveness in solving MaOPs.展开更多
N^(6)-methyladenosine(m^(6)A)on chromosome-associated regulatory RNAs(carRNAs),including repeat RNAs,plays important roles in tuning the chromatin state and transcription,but the intrinsic mechanism remains unclear.He...N^(6)-methyladenosine(m^(6)A)on chromosome-associated regulatory RNAs(carRNAs),including repeat RNAs,plays important roles in tuning the chromatin state and transcription,but the intrinsic mechanism remains unclear.Here,we report that YTHDC1 plays indispensable roles in the self-renewal and differentiation potency of mouse embryonic stem cells(ESCs),which highly depends on the m^(6)A-binding ability.Ythdcl is required for sufficient rRNA synthesis and repression of the 2-cell(2C)transcriptional program in ESCs,which recapitulates the transcriptome regulation by the LINE1 scaffold.Detailed analyses revealed that YTHDC1 recognizes m^(6)A on LINE1 RNAs in the nucleus and regulates the formation of the LINE1-NCL partnership and the chromatin recruitment of KAP1.Moreover,the establishment of H3K9me3 on 2C-related retrotrans-posons is interrupted in Ythdcl-depleted ESCs and inner cell mass(ICM)cells,which consequently increases the transcriptional activities.Our study reveals a role of m^(6)A in regulating the RNA scaffold,providing a new model for the RNA-chromatin cross-talk.展开更多
基金supported in part by the National Natural Science Foundation of China(51775385)the Natural Science Foundation of Shanghai(23ZR1466000)+3 种基金the Shanghai Industrial Collaborative Science and Technology Innovation Project(2021-cyxt2-kj10)the Innovation Program of Shanghai Municipal Education Commission(202101070007E00098)the Innovation Project of Engineering Research Center of Integration and Application of Digital Learning Technology of MOE(1221046)the Program to Cultivate Middle-Aged and Young Cadre Teacher of Jiangsu Province。
文摘In solving many-objective optimization problems(MaO Ps),existing nondominated sorting-based multi-objective evolutionary algorithms suffer from the fast loss of selection pressure.Most candidate solutions become nondominated during the evolutionary process,thus leading to the failure of producing offspring toward Pareto-optimal front with diversity.Can we find a more effective way to select nondominated solutions and resolve this issue?To answer this critical question,this work proposes to evolve solutions through line complex rather than solution points in Euclidean space.First,Plücker coordinates are used to project solution points to line complex composed of position vectors and momentum ones.Besides position vectors of the solution points,momentum vectors are used to extend the comparability of nondominated solutions and enhance selection pressure.Then,a new distance function designed for high-dimensional space is proposed to replace Euclidean distance as a more effective distancebased estimator.Based on them,a novel many-objective evolutionary algorithm(MaOEA)is proposed by integrating a line complex-based environmental selection strategy into the NSGAⅢframework.The proposed algorithm is compared with the state of the art on widely used benchmark problems with up to 15 objectives.Experimental results demonstrate its superior competitiveness in solving MaOPs.
基金This work was supported by the National Key R&D Program of China(2016YFA0100400,2020YFA0113200,2018YFA0108900 and 2016YFC1000600)the National Natural Science Foundation of China(31922022,31771646,82022027,31721003,31970796,31871448 and 31871446)+3 种基金the Shanghai Rising-Star Program(19QA1409600)the Shanghai Municipal Medical and Health Discipline Construction Projects(2017ZZ02015)the Fundamental Research Funds for the Central Universities(1515219049 and 22120200410)the Major Program of the Development Fund for Shanghai Zhangjiang National Innovation Demonstration Zone(ZJ2018-ZD-004).
文摘N^(6)-methyladenosine(m^(6)A)on chromosome-associated regulatory RNAs(carRNAs),including repeat RNAs,plays important roles in tuning the chromatin state and transcription,but the intrinsic mechanism remains unclear.Here,we report that YTHDC1 plays indispensable roles in the self-renewal and differentiation potency of mouse embryonic stem cells(ESCs),which highly depends on the m^(6)A-binding ability.Ythdcl is required for sufficient rRNA synthesis and repression of the 2-cell(2C)transcriptional program in ESCs,which recapitulates the transcriptome regulation by the LINE1 scaffold.Detailed analyses revealed that YTHDC1 recognizes m^(6)A on LINE1 RNAs in the nucleus and regulates the formation of the LINE1-NCL partnership and the chromatin recruitment of KAP1.Moreover,the establishment of H3K9me3 on 2C-related retrotrans-posons is interrupted in Ythdcl-depleted ESCs and inner cell mass(ICM)cells,which consequently increases the transcriptional activities.Our study reveals a role of m^(6)A in regulating the RNA scaffold,providing a new model for the RNA-chromatin cross-talk.
