AIM:To explore the factors influencing individuals’willingness to participate in ophthalmic clinical trials.METHODS:A questionnaire survey was conducted from January to April 2021 among patients and their family memb...AIM:To explore the factors influencing individuals’willingness to participate in ophthalmic clinical trials.METHODS:A questionnaire survey was conducted from January to April 2021 among patients and their family members at Zhongshan Ophthalmic Center,Sun Yat-sen University,in Guangzhou,China.The survey gathered data on respondents’willingness,demographic and socioeconomic profiles,as well as their reasons and concerns regarding engagement in clinical trials.RESULTS:Of the 1078 residents surveyed(mean age 31.2±13.1y;65.8%females)in Guangzhou,749(69.5%)expressed a willingness to participate in future ophthalmic clinical trials.Specific characteristics associated with greater willingness included a younger age,lower annual income,higher education,prior participation experience,previous ophthalmic treatment,and a better understanding of clinical trials.With the exception of age,these characteristics were significantly linked to a higher willingness.The primary barrier to participation,expressed by 64.8%of those willing and 54.4%of those unwilling,was“Uncertain efficacy”.In terms of motivations,the willing group ranked“Better therapeutic benefits”(35.0%),“Professional monitoring”(34.3%),and“Trust in healthcare professionals”(33.1%)as their top three reasons,whereas the unwilling participants indicated“Full comprehension of the protocol”(46.2%)as the key facilitator.CONCLUSION:This study reveals a substantial willingness to participate in ophthalmic clinical trials and demonstrates the predictive role of demographic and socioeconomic factors.Variations in motivators and concerns between willing and unwilling participants highlight the significance of tailored recruitment strategies.Importantly,the need for and trust in healthcare professionals stand out as powerful motivations,underscoring the importance of enhancing physician-patient relationships,adopting patient-centered communication approaches,and addressing individualized needs to improve accrual rates.展开更多
Cassava is a crucial crop that makes a significant contribution to ensuring human food security.However,high-quality telomere-totelomere cassava genomes have not been available up to now,which has restricted the progr...Cassava is a crucial crop that makes a significant contribution to ensuring human food security.However,high-quality telomere-totelomere cassava genomes have not been available up to now,which has restricted the progress of haploid molecular breeding for cassava.In this study,we constructed two nearly complete haploid resolved genomes and an integrated,telomere-to-telomere gap-free reference genome of an excellent cassava variety,‘Xinxuan 048’,thereby providing a new high-quality genomic resource.Furthermore,the evolutionary history of several species within the Euphorbiaceae family was revealed.Through comparative analysis of haploid genomes,it was found that two haploid genomes had extensive differences in linear structure,transcriptome features,and epigenetic characteristics.Genes located within the highly divergent regions and differentially expressed alleles are enriched in the functions of auxin response and the starch synthesis pathway.The high heterozygosity of cassava‘Xinxuan 048’leads to rapid trait segregation in the first selfed generation.This study provides a theoretical basis and genomic resource for molecular breeding of cassava haploids.展开更多
The recent pandemic of coronavirus disease 2019(COVID-19)caused by SARS-CoV-2 has raised global health concerns.The viral 3-chymotrypsin-like cysteine protease(3CL^pro)enzyme controls coronavirus replication and is es...The recent pandemic of coronavirus disease 2019(COVID-19)caused by SARS-CoV-2 has raised global health concerns.The viral 3-chymotrypsin-like cysteine protease(3CL^pro)enzyme controls coronavirus replication and is essential for its life cycle.3CL^pro is a proven drug discovery target in the case of severe acute respiratory syndrome coronavirus(SARS-CoV)and Middle East respiratory syndrome coronavirus(MERS-CoV).Recent studies revealed that the genome sequence of SARS-CoV-2 is very similar to that of SARS-CoV.Therefore,herein,we analysed the 3CL^pro sequence,constructed its 3D homology model,and screened it against a medicinal plant library containing 32,297 potential anti-viral phytochemicals/traditional Chinese medicinal compounds.Our analyses revealed that the top nine hits might serve as potential anti-SARS-CoV-2 lead molecules for further optimisation and drug development process to combat COVID-19.展开更多
The papain-like protease(PLpro)is vital for the replication of coronaviruses(Co Vs),as well as for escaping innate-immune responses of the host.Hence,it has emerged as an attractive antiviral drug-target.In this study...The papain-like protease(PLpro)is vital for the replication of coronaviruses(Co Vs),as well as for escaping innate-immune responses of the host.Hence,it has emerged as an attractive antiviral drug-target.In this study,computational approaches were employed,mainly the structure-based virtual screening coupled with all-atom molecular dynamics(MD)simulations to computationally identify specific inhibitors of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)PLpro,which can be further developed as potential pan-PLprobased broad-spectrum antiviral drugs.The sequence,structure,and functional conserveness of most deadly human Co Vs PLprowere explored,and it was revealed that functionally important catalytic triad residues are well conserved among SARS-Co V,SARS-Co V-2,and middle east respiratory syndrome coronavirus(MERS-Co V).The subsequent screening of a focused protease inhibitors database composed of^7,000 compounds resulted in the identification of three candidate compounds,ADM13083841,LMG15521745,and SYN15517940.These three compounds established conserved interactions which were further explored through MD simulations,free energy calculations,and residual energy contribution estimated by MM-PB(GB)SA method.All these compounds showed stable conformation and interacted well with the active residues of SARS-Co V-2 PLpro,and showed consistent interaction profile with SARS-Co V PLproand MERS-Co V PLproas well.Conclusively,the reported SARS-Co V-2 PLprospecific compounds could serve as seeds for developing potent pan-PLprobased broad-spectrum antiviral drugs against deadly human coronaviruses.Moreover,the presented information related to binding site residual energy contribution could lead to further optimization of these compounds.展开更多
Objective:To evaluate the effect of individualized nutritional intervention therapy in patients with gestational diabetes mellitus(GDM).Methods:80 GDM inpatients admitted to the First Affiliated Hospital of Hainan Med...Objective:To evaluate the effect of individualized nutritional intervention therapy in patients with gestational diabetes mellitus(GDM).Methods:80 GDM inpatients admitted to the First Affiliated Hospital of Hainan Medical College from December 2015 to June 2018 were enrolled.According to the random number table method,the patients were divided into 4 groups,with 20 cases in each group.Group 1 used food exchange combined glycemic index method,group 2 used food exchange combined blood glucose load method,group 3 used glycemic index combined with blood glucose load method,group 4 combined glycemic index and blood glucose load method based on food exchange.After the intervention,the changes of blood glucose level,biochemical indexes and fetal growth and development indexes of the four groups were observed.Results:After nutritional intervention,the blood glucose levels of the four groups of patients decreased to varying degrees compared with before the intervention.The difference was statistically significant(P<0.05).In order to evaluate the advantages and disadvantages of the four methods,the blood glucose levels of the four groups of patients were further compared between groups:compared with group 1,group 2,group 4 and group 3,the differences were statistically significant(P<0.01 or 0.05).There was significant difference in blood glucose 2 hours after dinner between group 4 and group 1 and group 2(P<0.05).Comparing the biochemical indexes and fetal growth and development indexes of the four groups,the differences were not statistically significant(P>0.05).Conclusion:Individualized nutritional intervention therapy can significantly improve the blood glucose level of GDM patients,and at the same time meet the needs of the mother's own physiology and fetal growth and development.Among them,the nutrition intervention method that combines the glycemic index and the blood glucose load on the basis of the food exchange portion has a better effect on improving the blood glucose level of the patient.展开更多
Translational regulation is a critical step in the process of gene expression and governs the synthesis of proteins from mRNAs.Many studies have revealed translational regulation in plants in response to various envir...Translational regulation is a critical step in the process of gene expression and governs the synthesis of proteins from mRNAs.Many studies have revealed translational regulation in plants in response to various environmental stimuli.However,there have been no studies documenting the comprehensive landscape of translational regulation and allele-specific translational efficiency in multiple plant tissues,especially those of rice,a main staple crop that feeds nearly half of the world’s population.Here we used RNA sequencing and ribosome profiling data to analyze the transcriptome and translatome of an elite hybrid rice,Shanyou 63(SY63),and its parental varieties Zhenshan 97 and Minghui 63.The results revealed that gene expression patterns varied more among tissues than among varieties at the transcriptional and translational levels.We identified 3392 upstream open reading frames(uORFs),and the uORF-containing genes were enriched in transcription factors.Only 668 of 13492 long non-coding RNAs could be translated into peptides.Finally,we discovered numerous genes with allele-specific translational efficiency in SY63 and demonstrated that some cis-regulatory elements may contribute to allelic divergence in translational efficiency.Overall,these findings may improve our understanding of translational regulation in rice and provide information for molecular breeding research.展开更多
Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNA...Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNAs are expressed in a cell type-and tissue-specific manner and often localize to specific subcellular regions or organelles for functions.The dysregulation of circular RNAs from birth to death is linked to the pathogenesis and progression of diverse diseases.This review outlines how aberrant circular RNA biogenesis,subcellular location,and degradation are linked to disease progression,focusing on metaflammation and cancers.We also discuss potential therapeutic strategies and obstacles in targeting such disease-related circular RNAs.展开更多
Dear Editor,Eukaryotic life is a complex system(Trewavas,2006).Networks offer a reasonable means of describing complex life systems.Networks constructed for animals and plants have significantly furthered our understa...Dear Editor,Eukaryotic life is a complex system(Trewavas,2006).Networks offer a reasonable means of describing complex life systems.Networks constructed for animals and plants have significantly furthered our understanding of complex life systems and functional genomics(Consortium,2011;Walley et al.,2016;Altmann et al.,2020;Luck et al.,2020;McWhite et al.,2020;Zander et al.,2020).However,integrative networks spanning different layers of genetic information are lacking.展开更多
Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms t...Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms to date contain gaps and missing sequences.Here,we report the assembly and analysis of gap-free reference genome sequences for two elite O.sativa xian/indica rice varieties,Zhenshan 97 and Minghui 63,which are being used as a model system for studying heterosis and yield.Gap-free reference genomes provide the opportunity for a global view of the structure and function of centromeres.We show that all rice centromeric regions share conserved centromere-specific satellite motifs with different copy numbers and structures.In addition,the similarity of CentO repeats in the same chromosome is higher than across chromosomes,supporting a model of local expansion and homogenization.Both genomes have over 395 non-TE genes located in centromere regions,of which∼41%are actively transcribed.Two large structural variants at the end of chromosome 11 affect the copy number of resistance genes between the two genomes.The availability of the two gap-free genomes lays a solid foundation for further understanding genome structure and function in plants and breeding climate-resilient varieties.展开更多
There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes(OLEDs).In this contribution,we present a simple compound 3-(3-(4,6-dip...There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes(OLEDs).In this contribution,we present a simple compound 3-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-bromo-1,10-phenanthroline.It shows a high T_g of 112°C.The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5 eV.The LUMO level is derived as-3.0 eV,based on the optical bandgap.The low-temperature solid-state phosphorescent spectrum gives a triplet energy of ~2.36 eV.n-Doping with8-hydroxyquinolatolithium(Liq,1:1)leads to considerably improved electron mobility of 5.2×10^(-6)–5.8×10^(-5)cm^2V^(-1)s^(-1)at E=(2–5)-10~5V cm^(-1),in contrast with the triarylphosphine oxidephenantroline molecular conjugate we reported previously.It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation,introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.展开更多
Circular intronic RNAs(ci RNAs) escaping from DBR1 debranching of intron lariats are co-transcriptionally produced from prem RNA splicing, but their turnover and mechanism of action have remained elusive. We report th...Circular intronic RNAs(ci RNAs) escaping from DBR1 debranching of intron lariats are co-transcriptionally produced from prem RNA splicing, but their turnover and mechanism of action have remained elusive. We report that RNase H1 degrades a subgroup of ci RNAs in human cells. Many ci RNAs contain high GC% and tend to form DNA:RNA hybrids(R-loops) for RNase H1 cleavage, a process that appears to promote Pol II transcriptional elongation at ci RNA-producing loci. One ci RNA, ciankrd52, shows a stronger ability of R-loop formation than that of its cognate pre-m RNA by maintaining a locally open RNA structure in vitro. This allows the release of pre-m RNA from R-loops by ci-ankrd52 replacement and subsequent ci RNA removal via RNase H1 for efficient transcriptional elongation. We propose that such an R-loop dependent ci RNA degradation likely represents a mechanism that on one hand limits ci RNA accumulation by recruiting RNase H1 and on the other hand resolves Rloops for transcriptional elongation at some GC-rich ci RNA-producing loci.展开更多
基金Supported by the Science and Technology Program of Guangzhou(No.201803010066)the High-level Hospital Construction Project,Zhongshan Ophthalmic Center,Sun Yat-sen University(No.303010202).
文摘AIM:To explore the factors influencing individuals’willingness to participate in ophthalmic clinical trials.METHODS:A questionnaire survey was conducted from January to April 2021 among patients and their family members at Zhongshan Ophthalmic Center,Sun Yat-sen University,in Guangzhou,China.The survey gathered data on respondents’willingness,demographic and socioeconomic profiles,as well as their reasons and concerns regarding engagement in clinical trials.RESULTS:Of the 1078 residents surveyed(mean age 31.2±13.1y;65.8%females)in Guangzhou,749(69.5%)expressed a willingness to participate in future ophthalmic clinical trials.Specific characteristics associated with greater willingness included a younger age,lower annual income,higher education,prior participation experience,previous ophthalmic treatment,and a better understanding of clinical trials.With the exception of age,these characteristics were significantly linked to a higher willingness.The primary barrier to participation,expressed by 64.8%of those willing and 54.4%of those unwilling,was“Uncertain efficacy”.In terms of motivations,the willing group ranked“Better therapeutic benefits”(35.0%),“Professional monitoring”(34.3%),and“Trust in healthcare professionals”(33.1%)as their top three reasons,whereas the unwilling participants indicated“Full comprehension of the protocol”(46.2%)as the key facilitator.CONCLUSION:This study reveals a substantial willingness to participate in ophthalmic clinical trials and demonstrates the predictive role of demographic and socioeconomic factors.Variations in motivators and concerns between willing and unwilling participants highlight the significance of tailored recruitment strategies.Importantly,the need for and trust in healthcare professionals stand out as powerful motivations,underscoring the importance of enhancing physician-patient relationships,adopting patient-centered communication approaches,and addressing individualized needs to improve accrual rates.
基金supported by the National Natural Science Foundation of China(32100526,32270712)the Guangxi Natural Science Foundation(AD23026047)+4 种基金the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources(SKLCUSA-a202205,SKLCUSA-a03)Ba-Gui Scholar Program of Guangxi(To Z.G.H),the Project of Bama County for Talents in Science and Technology(20220008)Chief Expert of Tuberous Crops Innovation Team in Guangxi Province(nycytxgxcxtd-2023-11-01)the starting research grant for High-level Talents and Innovation and development multiplication plan from Guangxi University(2022BZRC015).
文摘Cassava is a crucial crop that makes a significant contribution to ensuring human food security.However,high-quality telomere-totelomere cassava genomes have not been available up to now,which has restricted the progress of haploid molecular breeding for cassava.In this study,we constructed two nearly complete haploid resolved genomes and an integrated,telomere-to-telomere gap-free reference genome of an excellent cassava variety,‘Xinxuan 048’,thereby providing a new high-quality genomic resource.Furthermore,the evolutionary history of several species within the Euphorbiaceae family was revealed.Through comparative analysis of haploid genomes,it was found that two haploid genomes had extensive differences in linear structure,transcriptome features,and epigenetic characteristics.Genes located within the highly divergent regions and differentially expressed alleles are enriched in the functions of auxin response and the starch synthesis pathway.The high heterozygosity of cassava‘Xinxuan 048’leads to rapid trait segregation in the first selfed generation.This study provides a theoretical basis and genomic resource for molecular breeding of cassava haploids.
基金This work was supported by the National Key Research and Development Program of China(2020YFC0845600)the Hubei Provincial Natural Science Foundation of China(2019CFA014)+1 种基金the Starting Research Grant for High-level Talents from Guangxi University,Nanning,ChinaPostdoctoral Research Platform Grant of Guangxi University,Nanning,China.
文摘The recent pandemic of coronavirus disease 2019(COVID-19)caused by SARS-CoV-2 has raised global health concerns.The viral 3-chymotrypsin-like cysteine protease(3CL^pro)enzyme controls coronavirus replication and is essential for its life cycle.3CL^pro is a proven drug discovery target in the case of severe acute respiratory syndrome coronavirus(SARS-CoV)and Middle East respiratory syndrome coronavirus(MERS-CoV).Recent studies revealed that the genome sequence of SARS-CoV-2 is very similar to that of SARS-CoV.Therefore,herein,we analysed the 3CL^pro sequence,constructed its 3D homology model,and screened it against a medicinal plant library containing 32,297 potential anti-viral phytochemicals/traditional Chinese medicinal compounds.Our analyses revealed that the top nine hits might serve as potential anti-SARS-CoV-2 lead molecules for further optimisation and drug development process to combat COVID-19.
基金the Starting Research Grant for High-level Talents from Guangxi Universitythe Postdoctoral Project from Guangxi University。
文摘The papain-like protease(PLpro)is vital for the replication of coronaviruses(Co Vs),as well as for escaping innate-immune responses of the host.Hence,it has emerged as an attractive antiviral drug-target.In this study,computational approaches were employed,mainly the structure-based virtual screening coupled with all-atom molecular dynamics(MD)simulations to computationally identify specific inhibitors of severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)PLpro,which can be further developed as potential pan-PLprobased broad-spectrum antiviral drugs.The sequence,structure,and functional conserveness of most deadly human Co Vs PLprowere explored,and it was revealed that functionally important catalytic triad residues are well conserved among SARS-Co V,SARS-Co V-2,and middle east respiratory syndrome coronavirus(MERS-Co V).The subsequent screening of a focused protease inhibitors database composed of^7,000 compounds resulted in the identification of three candidate compounds,ADM13083841,LMG15521745,and SYN15517940.These three compounds established conserved interactions which were further explored through MD simulations,free energy calculations,and residual energy contribution estimated by MM-PB(GB)SA method.All these compounds showed stable conformation and interacted well with the active residues of SARS-Co V-2 PLpro,and showed consistent interaction profile with SARS-Co V PLproand MERS-Co V PLproas well.Conclusively,the reported SARS-Co V-2 PLprospecific compounds could serve as seeds for developing potent pan-PLprobased broad-spectrum antiviral drugs against deadly human coronaviruses.Moreover,the presented information related to binding site residual energy contribution could lead to further optimization of these compounds.
基金National Natural Science Foundation(No.81860836)Research Cultivation Fund of the First Affiliated Hospital of Hainan Medical College(No.HYFYPY201602)
文摘Objective:To evaluate the effect of individualized nutritional intervention therapy in patients with gestational diabetes mellitus(GDM).Methods:80 GDM inpatients admitted to the First Affiliated Hospital of Hainan Medical College from December 2015 to June 2018 were enrolled.According to the random number table method,the patients were divided into 4 groups,with 20 cases in each group.Group 1 used food exchange combined glycemic index method,group 2 used food exchange combined blood glucose load method,group 3 used glycemic index combined with blood glucose load method,group 4 combined glycemic index and blood glucose load method based on food exchange.After the intervention,the changes of blood glucose level,biochemical indexes and fetal growth and development indexes of the four groups were observed.Results:After nutritional intervention,the blood glucose levels of the four groups of patients decreased to varying degrees compared with before the intervention.The difference was statistically significant(P<0.05).In order to evaluate the advantages and disadvantages of the four methods,the blood glucose levels of the four groups of patients were further compared between groups:compared with group 1,group 2,group 4 and group 3,the differences were statistically significant(P<0.01 or 0.05).There was significant difference in blood glucose 2 hours after dinner between group 4 and group 1 and group 2(P<0.05).Comparing the biochemical indexes and fetal growth and development indexes of the four groups,the differences were not statistically significant(P>0.05).Conclusion:Individualized nutritional intervention therapy can significantly improve the blood glucose level of GDM patients,and at the same time meet the needs of the mother's own physiology and fetal growth and development.Among them,the nutrition intervention method that combines the glycemic index and the blood glucose load on the basis of the food exchange portion has a better effect on improving the blood glucose level of the patient.
基金supported by the National Natural Science Foundation of China(31871269 and 32270712)the Hubei Provincial Natural Science Foundation of China(2019CFA014)a starting research grant for High-level Talents from Guangxi University.
文摘Translational regulation is a critical step in the process of gene expression and governs the synthesis of proteins from mRNAs.Many studies have revealed translational regulation in plants in response to various environmental stimuli.However,there have been no studies documenting the comprehensive landscape of translational regulation and allele-specific translational efficiency in multiple plant tissues,especially those of rice,a main staple crop that feeds nearly half of the world’s population.Here we used RNA sequencing and ribosome profiling data to analyze the transcriptome and translatome of an elite hybrid rice,Shanyou 63(SY63),and its parental varieties Zhenshan 97 and Minghui 63.The results revealed that gene expression patterns varied more among tissues than among varieties at the transcriptional and translational levels.We identified 3392 upstream open reading frames(uORFs),and the uORF-containing genes were enriched in transcription factors.Only 668 of 13492 long non-coding RNAs could be translated into peptides.Finally,we discovered numerous genes with allele-specific translational efficiency in SY63 and demonstrated that some cis-regulatory elements may contribute to allelic divergence in translational efficiency.Overall,these findings may improve our understanding of translational regulation in rice and provide information for molecular breeding research.
基金the National Key Research and Development Program of China(2021YFA1300502)the Natural Science Foundation of China(92057210,82125017,91942309)the Science and Technology Program of Guangzhou(202103000070)。
文摘Emerging lines of evidence have shown that the production of the covalently closed single-stranded circular RNAs is not splicing errors,but rather a regulated process with distinct biogenesis and turnover.Circular RNAs are expressed in a cell type-and tissue-specific manner and often localize to specific subcellular regions or organelles for functions.The dysregulation of circular RNAs from birth to death is linked to the pathogenesis and progression of diverse diseases.This review outlines how aberrant circular RNA biogenesis,subcellular location,and degradation are linked to disease progression,focusing on metaflammation and cancers.We also discuss potential therapeutic strategies and obstacles in targeting such disease-related circular RNAs.
基金supported by the National Natural Science Foundation of China(32272158,32270712,92035302)Outstanding Youth Team Project of Center Universities(2662023PY007).
文摘Dear Editor,Eukaryotic life is a complex system(Trewavas,2006).Networks offer a reasonable means of describing complex life systems.Networks constructed for animals and plants have significantly furthered our understanding of complex life systems and functional genomics(Consortium,2011;Walley et al.,2016;Altmann et al.,2020;Luck et al.,2020;McWhite et al.,2020;Zander et al.,2020).However,integrative networks spanning different layers of genetic information are lacking.
基金This research was supported by the Natinal Key Research and Development Program of China(2016YFD0100904 and 2016YFD0100802)the National Natural Science Foundation of China(31871269)+1 种基金the Hubei Provincial Natural Science Foundation of China(2019CFA014)Fundamental Research Funds for the Central Universities(2662020SKPY010 to J.Z.).
文摘Rice(Oryza sativa),a major staple throughout the world and a model system for plant genomics and breeding,was the first crop genome sequenced almost two decades ago.However,reference genomes for all higher organisms to date contain gaps and missing sequences.Here,we report the assembly and analysis of gap-free reference genome sequences for two elite O.sativa xian/indica rice varieties,Zhenshan 97 and Minghui 63,which are being used as a model system for studying heterosis and yield.Gap-free reference genomes provide the opportunity for a global view of the structure and function of centromeres.We show that all rice centromeric regions share conserved centromere-specific satellite motifs with different copy numbers and structures.In addition,the similarity of CentO repeats in the same chromosome is higher than across chromosomes,supporting a model of local expansion and homogenization.Both genomes have over 395 non-TE genes located in centromere regions,of which∼41%are actively transcribed.Two large structural variants at the end of chromosome 11 affect the copy number of resistance genes between the two genomes.The availability of the two gap-free genomes lays a solid foundation for further understanding genome structure and function in plants and breeding climate-resilient varieties.
基金supported by the National Key R&D Program of China(2016YFB0400701)NSFC-Guangdong Joint Program(U1301243)+1 种基金the National Basic Research Program of China(2015CB655000)support of Dongguan Major Special Project(2017215117010)
文摘There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes(OLEDs).In this contribution,we present a simple compound 3-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-bromo-1,10-phenanthroline.It shows a high T_g of 112°C.The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5 eV.The LUMO level is derived as-3.0 eV,based on the optical bandgap.The low-temperature solid-state phosphorescent spectrum gives a triplet energy of ~2.36 eV.n-Doping with8-hydroxyquinolatolithium(Liq,1:1)leads to considerably improved electron mobility of 5.2×10^(-6)–5.8×10^(-5)cm^2V^(-1)s^(-1)at E=(2–5)-10~5V cm^(-1),in contrast with the triarylphosphine oxidephenantroline molecular conjugate we reported previously.It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation,introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(91940303,31725009)the HHMI International Program(55008728)to L.-L.C.+2 种基金NSFC(31730111,31925011)to L.Y.Young Elite Scientists Sponsorship Program(2020QNRC001)to X.L.L.-L.C.the support from the XPLORER PRIZE.
文摘Circular intronic RNAs(ci RNAs) escaping from DBR1 debranching of intron lariats are co-transcriptionally produced from prem RNA splicing, but their turnover and mechanism of action have remained elusive. We report that RNase H1 degrades a subgroup of ci RNAs in human cells. Many ci RNAs contain high GC% and tend to form DNA:RNA hybrids(R-loops) for RNase H1 cleavage, a process that appears to promote Pol II transcriptional elongation at ci RNA-producing loci. One ci RNA, ciankrd52, shows a stronger ability of R-loop formation than that of its cognate pre-m RNA by maintaining a locally open RNA structure in vitro. This allows the release of pre-m RNA from R-loops by ci-ankrd52 replacement and subsequent ci RNA removal via RNase H1 for efficient transcriptional elongation. We propose that such an R-loop dependent ci RNA degradation likely represents a mechanism that on one hand limits ci RNA accumulation by recruiting RNase H1 and on the other hand resolves Rloops for transcriptional elongation at some GC-rich ci RNA-producing loci.
