Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation...Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.展开更多
In recent years,some super hybrid rice varieties were bred with strong culms and large panicles,which are mainly contributed by the ipa1-2D locus.A gain-of-function allele of OsSPL14 is the ipa1-2D and it can greatly ...In recent years,some super hybrid rice varieties were bred with strong culms and large panicles,which are mainly contributed by the ipa1-2D locus.A gain-of-function allele of OsSPL14 is the ipa1-2D and it can greatly increase the panicle primary branch number.However,the key downstream genes mediating this trait variation are not fully explored.In this study,we developed high-quality near-isogenic lines(NILs)with a difference of only 30 kb chromosomal segment covering the ipa1-2D locus.Using the NILs,we explored the impact of ipa1-2D on five sequential stages of early inflorescence development,and found that the locus can greatly enhance the initiation of primary branch meristems.A transcriptomic analysis was performed to unveil the downstream molecular network of ipa1-2D,and 87 genes were found differentially expressed,many of which are involved in metabolism and catalysis processes.In addition,transgenic lines of overexpression and RNA interference were generated to shape different levels of OsSPL14.They were also used to validate the expression variation explored by transcriptome.Based on the gene annotation,twelve potential downstream targets of ipa1-2D were selected,and their expression variation was confirmed by qRT-PCR analysis both in NILs and transgenic lines.This research expands the molecular network underlying ipa1-2D and provides novel gene information which might be involved in the control of panicle branching.We discussed the potential function of identified genes and highlighted their values for future function exploration and breeding application.展开更多
文摘Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.
文摘列表L(2,1)-标号是一个重要的可以应用到信道分配问题中的优化问题,k-L(2,1)-标号是指对于一个平面图G满足映射ϕ :V (G)→{0,1,…,k},使得若d(u,v)=1,则|ϕ(u)−ϕ(v)|≥2;若d(u,v)=2,则|ϕ(u)−ϕ(v)|≥1,其中d(u,v)是图中点u和点v之间的距离。记λ(2,1)l(G)=min{k|G有一列k-L(2,1)-标号}是列表L(2,1)-标号数。在2018年,Zhu and Bu等人在全局最优化杂志中得出这样一个结论:对于不含4-圈和6-圈的平面图G有λ(2,1)l(G)≤max{Δ+15,29}。本文改进了这个结论的上界λ(2,1)l(G)≤max{Δ+12,24}。
基金This work was supported by grants from the National Natural Science Foundation of China(31600990,31871217 and 32072037)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJA210002)+2 种基金Project of Special Funding for Crop Science Discipline Development(yzuxk202006)the open funds of the State Key Laboratory of Crop Genetics and Germplasm Enhancement(ZW202010)the Key Research and Development Program of Jiangsu Province(BE2018357).
文摘In recent years,some super hybrid rice varieties were bred with strong culms and large panicles,which are mainly contributed by the ipa1-2D locus.A gain-of-function allele of OsSPL14 is the ipa1-2D and it can greatly increase the panicle primary branch number.However,the key downstream genes mediating this trait variation are not fully explored.In this study,we developed high-quality near-isogenic lines(NILs)with a difference of only 30 kb chromosomal segment covering the ipa1-2D locus.Using the NILs,we explored the impact of ipa1-2D on five sequential stages of early inflorescence development,and found that the locus can greatly enhance the initiation of primary branch meristems.A transcriptomic analysis was performed to unveil the downstream molecular network of ipa1-2D,and 87 genes were found differentially expressed,many of which are involved in metabolism and catalysis processes.In addition,transgenic lines of overexpression and RNA interference were generated to shape different levels of OsSPL14.They were also used to validate the expression variation explored by transcriptome.Based on the gene annotation,twelve potential downstream targets of ipa1-2D were selected,and their expression variation was confirmed by qRT-PCR analysis both in NILs and transgenic lines.This research expands the molecular network underlying ipa1-2D and provides novel gene information which might be involved in the control of panicle branching.We discussed the potential function of identified genes and highlighted their values for future function exploration and breeding application.
