Aging is one of the greatest risk factors for morbidity caused by the coronavirus disease 2019(COVID19).In older individuals,a dysregulated immune response to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2...Aging is one of the greatest risk factors for morbidity caused by the coronavirus disease 2019(COVID19).In older individuals,a dysregulated immune response to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection contributes to disease severity;however,the underlying mechanism remains elusive.In this study,we established an aging mouse model of COVID-19,successfully replicating the development of a relatively severe disease in older adults.Further single-cell transcriptome analysis revealed a distinct immune cell landscape in the infected lungs,accompanied by an over-activated inflammatory response,especially in aging mice.Compared to young mice,aging mice showed extensive neutrophil activation,NETosis,and a dramatic decrease in the number of alveolar macrophages(AMs).Moreover,as important executors of efferocytosis,AMs exhibited a low efferocytotic gene signature and downregulation of multiple efferocytosis receptors in aged mice.Further analysis indicated that the efferocytosis of neutrophils,whether undergoing apoptosis or NETosis,was compromised after SARS-CoV-2 infection.Since efferocytosis is a key process in inflammatory resolution,impaired efferocytosis may contribute to hyperinflammation in aging lungs.Our study reveals the characteristics and role of efferocytosis in aging mice after SARS-CoV-2 infection and provides valuable insights for the potential treatment of COVID-19.展开更多
Sound transmission occurs in the cochlea,a complex and ingenious subdivision in the inner ear.The structure of the cochlea develops structurally and functionally by the time before two postnatal weeks(the time of hear...Sound transmission occurs in the cochlea,a complex and ingenious subdivision in the inner ear.The structure of the cochlea develops structurally and functionally by the time before two postnatal weeks(the time of hearing onset)in mice(Geal-Dor et al.,1993).Greater epithelial ridge(GER,also known as Kolliker's organ)is a transient cochlear structure containing a group of columnar epithelial supporting cells surrounding the inner hair cells(IHCs).展开更多
Because of the higher nitrogen(N)recovery efficiency(NRE)of panicle-stage fertilization compared with basal and tillering fertilization,increasing the proportion of N topdressing at the booting stage(panicleN)is recom...Because of the higher nitrogen(N)recovery efficiency(NRE)of panicle-stage fertilization compared with basal and tillering fertilization,increasing the proportion of N topdressing at the booting stage(panicleN)is recommended and commonly practiced in parts of China.To investigate the effects of increasing panicle-N on grain yield and N use efficiency(NUE)and the relationships of the increase and the rice cultivar and soil fertility status,we increased the percentage of panicle-N from 20%to 40%by correspondingly reducing the N amount applied only at the tillering stage in both high-and low-fertility blue clayey paddy fields in 2018 and 2019.Four indica cultivars with diverse panicle types were used,and their grain yield,dry matter accumulation,and NUE were compared.In high-fertility soil,increasing topdressing panicle-N from 20%to 40%reduced tillering ability and reduced the effective panicle numbers of the multi-and medium-panicle cultivars Huanghuazhan(HHZ),C Liangyouhuazhan(CHZ),and Tianyouhuazhan(THZ).These cultivars gave the greatest yield when 30%of N was supplied as panicle fertilizer,whereas the yield,NRE,N agronomic efficiency(NAE),and nitrogen physiological efficiency(NPE)of the heavy-panicle inbred cultivar Yangdao 6(YD6)continued to increase,resulting in improved dry matter accumulation and grain filling in the late growth stage.The yield,NAE,NRE,and NPE of YD6 peaked when the panicle-N constituted 40%.While in low-fertility soil,the multipanicle cultivar HHZ showed the greatest yield when 30%of fertilizer-N was applied once at the panicle initiation(PI)stage,while the medium-panicle cultivar CHZ showed the greatest yield when the panicle-N percentage was 40%.Our results suggest that the percentage of panicle-N fertilizer should not exceed 30%for multipanicle cultivars,while can be appropriately increased to 40%for heavy-panicle indica cultivars.The effect of increasing topdressing panicle-N on the yield of medium-panicle cultivars was related to soil fertility.The optimum panicle-N percentage was 30%in the high-fertility soil and 40%in the low-fertility soil.展开更多
There is a growing interest in developing experimental methods for tracking the developmental cell lineages of a complex organism.The recently developed CRISPR/Cas9-based barcoding method is,although highly promising,...There is a growing interest in developing experimental methods for tracking the developmental cell lineages of a complex organism.The recently developed CRISPR/Cas9-based barcoding method is,although highly promising,difficult to scale up because it relies on exogenous barcoding sequences that are engineered into the genome.In this study,we characterized 78 high-quality endogenous sites in the zebrafish genome that can be used as CRISPR/Cas9-based barcoding sites.The 78 sites are all highly expressed in most of the cell types according to single-cell RNA sequencing(scRNA-seq)data.Hence,the barcoding information of the 78 endogenous sites is recovered by the available scRNA-seq platforms,enabling simultaneous characterization of cell type and cell lineage information.展开更多
基金supported by the National Key Research and Development Program of China(NKPs)(2022YFC2604101).
文摘Aging is one of the greatest risk factors for morbidity caused by the coronavirus disease 2019(COVID19).In older individuals,a dysregulated immune response to severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection contributes to disease severity;however,the underlying mechanism remains elusive.In this study,we established an aging mouse model of COVID-19,successfully replicating the development of a relatively severe disease in older adults.Further single-cell transcriptome analysis revealed a distinct immune cell landscape in the infected lungs,accompanied by an over-activated inflammatory response,especially in aging mice.Compared to young mice,aging mice showed extensive neutrophil activation,NETosis,and a dramatic decrease in the number of alveolar macrophages(AMs).Moreover,as important executors of efferocytosis,AMs exhibited a low efferocytotic gene signature and downregulation of multiple efferocytosis receptors in aged mice.Further analysis indicated that the efferocytosis of neutrophils,whether undergoing apoptosis or NETosis,was compromised after SARS-CoV-2 infection.Since efferocytosis is a key process in inflammatory resolution,impaired efferocytosis may contribute to hyperinflammation in aging lungs.Our study reveals the characteristics and role of efferocytosis in aging mice after SARS-CoV-2 infection and provides valuable insights for the potential treatment of COVID-19.
基金supported by the National Natural Science Foundation of China(82171136 and 81970888 to G.W.,32330044 to Y.S.S.)Fundamental Research Funds for the Central Universities(021414380533toG.W.).
文摘Sound transmission occurs in the cochlea,a complex and ingenious subdivision in the inner ear.The structure of the cochlea develops structurally and functionally by the time before two postnatal weeks(the time of hearing onset)in mice(Geal-Dor et al.,1993).Greater epithelial ridge(GER,also known as Kolliker's organ)is a transient cochlear structure containing a group of columnar epithelial supporting cells surrounding the inner hair cells(IHCs).
文摘太阳敏感器作为检测太阳矢量方位角的一种光学仪器,是卫星进行姿态测量、确定和控制的重要敏感器.随着天基对日观测活动的发展,对日精确指向需求强烈,太阳敏感器的精度和数据更新率成为制约对日观测平台稳态控制和精确观测的关键因素.针对太阳敏感器高精度和高更新率的需求,从光学系统、电路系统和软件算法等多个角度出发,设计了一种太阳敏感器,经标定测试,精度随机误差达到0.716″(3σ),更新率达到62 Hz.
基金supported by the China Agriculture Research System(CARS-01-04A)the National Natural Science Foundation of China(31371581)。
文摘Because of the higher nitrogen(N)recovery efficiency(NRE)of panicle-stage fertilization compared with basal and tillering fertilization,increasing the proportion of N topdressing at the booting stage(panicleN)is recommended and commonly practiced in parts of China.To investigate the effects of increasing panicle-N on grain yield and N use efficiency(NUE)and the relationships of the increase and the rice cultivar and soil fertility status,we increased the percentage of panicle-N from 20%to 40%by correspondingly reducing the N amount applied only at the tillering stage in both high-and low-fertility blue clayey paddy fields in 2018 and 2019.Four indica cultivars with diverse panicle types were used,and their grain yield,dry matter accumulation,and NUE were compared.In high-fertility soil,increasing topdressing panicle-N from 20%to 40%reduced tillering ability and reduced the effective panicle numbers of the multi-and medium-panicle cultivars Huanghuazhan(HHZ),C Liangyouhuazhan(CHZ),and Tianyouhuazhan(THZ).These cultivars gave the greatest yield when 30%of N was supplied as panicle fertilizer,whereas the yield,NRE,N agronomic efficiency(NAE),and nitrogen physiological efficiency(NPE)of the heavy-panicle inbred cultivar Yangdao 6(YD6)continued to increase,resulting in improved dry matter accumulation and grain filling in the late growth stage.The yield,NAE,NRE,and NPE of YD6 peaked when the panicle-N constituted 40%.While in low-fertility soil,the multipanicle cultivar HHZ showed the greatest yield when 30%of fertilizer-N was applied once at the panicle initiation(PI)stage,while the medium-panicle cultivar CHZ showed the greatest yield when the panicle-N percentage was 40%.Our results suggest that the percentage of panicle-N fertilizer should not exceed 30%for multipanicle cultivars,while can be appropriately increased to 40%for heavy-panicle indica cultivars.The effect of increasing topdressing panicle-N on the yield of medium-panicle cultivars was related to soil fertility.The optimum panicle-N percentage was 30%in the high-fertility soil and 40%in the low-fertility soil.
基金We are grateful to J.Huang and Z.Zhang for technical support.This work was supported by a grant from the National Key Program of China(2017YFA0103504 to X.H.)。
文摘There is a growing interest in developing experimental methods for tracking the developmental cell lineages of a complex organism.The recently developed CRISPR/Cas9-based barcoding method is,although highly promising,difficult to scale up because it relies on exogenous barcoding sequences that are engineered into the genome.In this study,we characterized 78 high-quality endogenous sites in the zebrafish genome that can be used as CRISPR/Cas9-based barcoding sites.The 78 sites are all highly expressed in most of the cell types according to single-cell RNA sequencing(scRNA-seq)data.Hence,the barcoding information of the 78 endogenous sites is recovered by the available scRNA-seq platforms,enabling simultaneous characterization of cell type and cell lineage information.
