This paper reports results from the first long-term BV(RI)c photometric CCD observations of three variable pre-main-sequence stars collected during the period from February 2007 to January 2020. The investigated stars...This paper reports results from the first long-term BV(RI)c photometric CCD observations of three variable pre-main-sequence stars collected during the period from February 2007 to January 2020. The investigated stars are located in the field of the PMS star V733 Cep within the Cepheus OB3 association. All stars from our study show rapid photometric variability in all-optical passbands. In this paper, we describe and discuss the photometric behavior of these stars and the possible reasons for their variability. In the light variation of two of the stars, we found periodicity.展开更多
The pursuit of complete telomere-to-telomere(T2T)genome assembly in plants,challenged by genomic complexity,has been advanced by Oxford Nanopore Technologies(ONT),which offers ultra-long,realtime sequencing.Despite it...The pursuit of complete telomere-to-telomere(T2T)genome assembly in plants,challenged by genomic complexity,has been advanced by Oxford Nanopore Technologies(ONT),which offers ultra-long,realtime sequencing.Despite its promise,sequencing length and gap filling remain significant challenges.This study optimized DNA extraction and library preparation,achieving DNA lengths exceeding 485 kb;average N50 read lengths of 80.57 kb,reaching up to 440 kb;and maximum reads of 5.83 Mb.Importantly,we demonstrated that combining ultra-long sequencing and adaptive sampling can effectively fill gaps during assembly,evidenced by successfully filling the remaining gaps of a near-complete Arabidopsis genome assembly and resolving the sequence of an unknown telomeric region in watermelon genome.Collectively,our strategies improve the feasibility of complete T2T genomic assemblies across various plant species,enhancing genome-based research in diverse fields.展开更多
Whole-exome sequencing(WES)data are frequently used for cancer diagnosis and genome-wide association studies(GWAS),based on high-coverage read mapping,informative variant calling,and high-quality reference genomes.The...Whole-exome sequencing(WES)data are frequently used for cancer diagnosis and genome-wide association studies(GWAS),based on high-coverage read mapping,informative variant calling,and high-quality reference genomes.The center position of the currently used genome assembly,GRCh38,is now challenged by two newly published telomere-to-telomere(T2T)genomes,T2T-CHM13 and T2T-YAO,and it becomes urgent to have a comparative study to test population specificity using the three reference genomes based on real case WES data.Here,we report our analysis along this line for 19 tumor samples collected from Chinese patients.The primary comparison of the exon regions among the three references reveals that the sequences in up to∼1%of target regions in T2T-YAO are widely diversified from GRCh38 and may lead to off-target in sequence capture.However,T2T-YAO still outperforms GRCh38 by obtaining 7.41%of more mapped reads.Due to more reliable read-mapping and closer phylogenetic relationship with the samples than GRCh38,T2T-YAO reduces half of variant calls of clinical significance which are mostly benign,while maintaining sensitivity in identifying pathogenic variants.T2T-YAO also outperforms T2T-CHM13 in reducing calls of Chinese-specific variants.Our findings highlight the critical need for employing population-specific reference genomes in genomic analysis to ensure accurate variant analysis and the significant benefits of tailoring these approaches to the unique genetic background of each ethnic group.展开更多
Signaling via interleukin-2 receptor(IL-2R)is a requisite for regulatory T(Treg)cell identity and function.However,it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis,l...Signaling via interleukin-2 receptor(IL-2R)is a requisite for regulatory T(Treg)cell identity and function.However,it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis,lineage stability and function in both resting and inflammatory conditions.Here,we characterized a spontaneous mutant mouse strain endowed with a hypomorphic Tyr129His variant of CD25,theα-chain of IL-2R,which resulted in diminished receptor expression and reduced IL-2R signaling.Under noninflammatory conditions,Cd25Y129H mice harbored substantially lower numbers of peripheral Treg cells with stable Foxp3 expression that prevented the development of spontaneous autoimmune disease.In contrast,Cd25^(Y^(129H))Treg cells failed to efficiently induce immune suppression and lost lineage commitment in a T-cell transfer colitis model,indicating that unimpaired IL-2R signaling is critical for Treg cell function in inflammatory environments.Moreover,single-cell RNA sequencing of Treg cells revealed that impaired IL-2R signaling profoundly affected the balance of central and effector Treg cell subsets.Thus,partial loss of IL-2R signaling differentially interferes with the maintenance,heterogeneity,and suppressive function of the Treg cell pool.展开更多
Apart from their primordial role in protein synthesis,t RNAs can be cleaved to produce t RNA-derived small RNAs(ts RNAs).The biological functions of ts RNAs in plants remain largely unknown.In this study,we developed ...Apart from their primordial role in protein synthesis,t RNAs can be cleaved to produce t RNA-derived small RNAs(ts RNAs).The biological functions of ts RNAs in plants remain largely unknown.In this study,we developed Rtc B ligation-based small RNA(s RNA)sequencing,a method that captures and distinguishes between 3′-2′,3′-cyclic-phosphate(c P)/phosphate(P)-terminated s RNAs and 3′-OH-terminated s RNAs,and profiled 5′ts RNAs and 5′t RNA halves in Arabidopsis thaliana.We found that Arabidopsis 5′ts RNAs and 5′t RNA halves predominantly contain a c P at the 3′end and require S-like RNase 1(RNS1)and RNS3 for their production.One of the most abundant 5′ts RNAs,5′ts R-Ala,by associating with AGO1,negatively regulates Cytochrome P45071 A13(CYP71 A13)expression and camalexin biosynthesis to repress anti-fungal defense.Interestingly,5′ts R-Ala is downregulated upon fungal infection.Our study provides a global view of 5′ts RNAs and 5′t RNA halves in Arabidopsis and unravels an important role of a 5′ts RNA in regulating anti-fungal defense.展开更多
基金partly supported by the Bulgarian Ministry of Education and Science under the National Program for Research“Young Scientists and Postdoctoral Students”partial support by grant DN 18-13/2017 from the Bulgarian National Science Fund。
文摘This paper reports results from the first long-term BV(RI)c photometric CCD observations of three variable pre-main-sequence stars collected during the period from February 2007 to January 2020. The investigated stars are located in the field of the PMS star V733 Cep within the Cepheus OB3 association. All stars from our study show rapid photometric variability in all-optical passbands. In this paper, we describe and discuss the photometric behavior of these stars and the possible reasons for their variability. In the light variation of two of the stars, we found periodicity.
基金supported by the Key R&D Program of Shandong Province,China(grant no.ZR202211070163)the National Natural Science Foundation of China(grant nos.32170574 and 32200249)+1 种基金the Natural Science Foundation of Shandong Province(grant nos.ZR2023QC026 and ZR2023QC106)the Young Taishan Scholars Program and Yuandu Scholars Program.
文摘The pursuit of complete telomere-to-telomere(T2T)genome assembly in plants,challenged by genomic complexity,has been advanced by Oxford Nanopore Technologies(ONT),which offers ultra-long,realtime sequencing.Despite its promise,sequencing length and gap filling remain significant challenges.This study optimized DNA extraction and library preparation,achieving DNA lengths exceeding 485 kb;average N50 read lengths of 80.57 kb,reaching up to 440 kb;and maximum reads of 5.83 Mb.Importantly,we demonstrated that combining ultra-long sequencing and adaptive sampling can effectively fill gaps during assembly,evidenced by successfully filling the remaining gaps of a near-complete Arabidopsis genome assembly and resolving the sequence of an unknown telomeric region in watermelon genome.Collectively,our strategies improve the feasibility of complete T2T genomic assemblies across various plant species,enhancing genome-based research in diverse fields.
基金supported by grants from the National Key R&DäProgram of China(Grant No.2021YFC 2301000)the National Science Foundation of China(Grant No.32371537)+2 种基金the Linfen Soft Science Research Project(Grant No.2126)the National and Provincial Key Clinical Specialty Capacity Building Project 2020(Department of the Respiratory Medicine)the Peking University People's Hospital Scientific Research Development Funds(Grant No.RDGS2022-11),China.
文摘Whole-exome sequencing(WES)data are frequently used for cancer diagnosis and genome-wide association studies(GWAS),based on high-coverage read mapping,informative variant calling,and high-quality reference genomes.The center position of the currently used genome assembly,GRCh38,is now challenged by two newly published telomere-to-telomere(T2T)genomes,T2T-CHM13 and T2T-YAO,and it becomes urgent to have a comparative study to test population specificity using the three reference genomes based on real case WES data.Here,we report our analysis along this line for 19 tumor samples collected from Chinese patients.The primary comparison of the exon regions among the three references reveals that the sequences in up to∼1%of target regions in T2T-YAO are widely diversified from GRCh38 and may lead to off-target in sequence capture.However,T2T-YAO still outperforms GRCh38 by obtaining 7.41%of more mapped reads.Due to more reliable read-mapping and closer phylogenetic relationship with the samples than GRCh38,T2T-YAO reduces half of variant calls of clinical significance which are mostly benign,while maintaining sensitivity in identifying pathogenic variants.T2T-YAO also outperforms T2T-CHM13 in reducing calls of Chinese-specific variants.Our findings highlight the critical need for employing population-specific reference genomes in genomic analysis to ensure accurate variant analysis and the significant benefits of tailoring these approaches to the unique genetic background of each ethnic group.
基金This work was supported by the ERC Advanced Grants 322645,SFB900-B1,and SFB738-B5(all to R.F.)and SFB738-C7(to J.H.).We gratefully acknowledge the assistance of Dr.Matthias Ballmaier of the Cell Sorting Core Facility of Hannover Medical School for superb service.The cDNA and HTO libraries used in this publication were sequenced at the Research Core Unit Genomics at Hannover Medical School.We thank Svetlana Piter for providing excellent animal care and Natalio Garbi(IEI Bonn)for providing Ccr2^(−/−)(Ccr2^(tm1Mae))mice.
文摘Signaling via interleukin-2 receptor(IL-2R)is a requisite for regulatory T(Treg)cell identity and function.However,it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis,lineage stability and function in both resting and inflammatory conditions.Here,we characterized a spontaneous mutant mouse strain endowed with a hypomorphic Tyr129His variant of CD25,theα-chain of IL-2R,which resulted in diminished receptor expression and reduced IL-2R signaling.Under noninflammatory conditions,Cd25Y129H mice harbored substantially lower numbers of peripheral Treg cells with stable Foxp3 expression that prevented the development of spontaneous autoimmune disease.In contrast,Cd25^(Y^(129H))Treg cells failed to efficiently induce immune suppression and lost lineage commitment in a T-cell transfer colitis model,indicating that unimpaired IL-2R signaling is critical for Treg cell function in inflammatory environments.Moreover,single-cell RNA sequencing of Treg cells revealed that impaired IL-2R signaling profoundly affected the balance of central and effector Treg cell subsets.Thus,partial loss of IL-2R signaling differentially interferes with the maintenance,heterogeneity,and suppressive function of the Treg cell pool.
基金supported by the National Natural Science Foundation of China(31801074,31788103)。
文摘Apart from their primordial role in protein synthesis,t RNAs can be cleaved to produce t RNA-derived small RNAs(ts RNAs).The biological functions of ts RNAs in plants remain largely unknown.In this study,we developed Rtc B ligation-based small RNA(s RNA)sequencing,a method that captures and distinguishes between 3′-2′,3′-cyclic-phosphate(c P)/phosphate(P)-terminated s RNAs and 3′-OH-terminated s RNAs,and profiled 5′ts RNAs and 5′t RNA halves in Arabidopsis thaliana.We found that Arabidopsis 5′ts RNAs and 5′t RNA halves predominantly contain a c P at the 3′end and require S-like RNase 1(RNS1)and RNS3 for their production.One of the most abundant 5′ts RNAs,5′ts R-Ala,by associating with AGO1,negatively regulates Cytochrome P45071 A13(CYP71 A13)expression and camalexin biosynthesis to repress anti-fungal defense.Interestingly,5′ts R-Ala is downregulated upon fungal infection.Our study provides a global view of 5′ts RNAs and 5′t RNA halves in Arabidopsis and unravels an important role of a 5′ts RNA in regulating anti-fungal defense.
