Alkaline stress in saline soil limits cotton production that may be improved by using emerging nanobiotechnology approaches.Here,we applied poly acrylic acid coated Mn3O4 nanoparticles(PMO)on cotton leaves which showe...Alkaline stress in saline soil limits cotton production that may be improved by using emerging nanobiotechnology approaches.Here,we applied poly acrylic acid coated Mn3O4 nanoparticles(PMO)on cotton leaves which showed higher chlorophyll content(up to 100.0%)and fresh weight(46.9%)and lower electrolyte leakage rate(up to 6.8%)and cell death rate(up to 84.8%)than controls.Further investigation showed that PMO can maintain reactive oxygen species(ROS)homeostasis,increase the stability of actin filament(AF),and reduce Na^(+)content.Confocal imaging and ROS content measurement showed that PMO foliar application effectively alleviated ROS over-accumulation(up to 16.4%decrease for H_(2)O_(2)and 45.3%decrease for O_(2)^(•-))in cotton leaves.Moreover,under alkaline stress,genes for AF depolymerization such as GhADF1/8 and GhADF6 and for AF polymerization such as GhADF5 were significantly down-regulated in PMO treated cotton lines relative to those in the control,consistent with the fluorescence intensities of AFs.Furthermore,our results showed that PMO mitigated Na^(+)toxicity under alkaline stress,as indicated by the reduced Na^(+)fluorescence intensity and Na^(+)content.Furthermore,relative to those of the control,PMO treatment increased seed yield and lint yield by 65.0%and 66.3%respectively.Together,our work demonstrates that ROS scavenging PMO alleviated alkaline stress by stabilizing actin filaments and reducing Na^(+)toxicity.展开更多
Cell division is a fundamental biological process in which a parent cell divides into two daughter cells.The cell cortex,a thin layer primarily composed of actin filaments and myosin motors beneath the plasma membrane...Cell division is a fundamental biological process in which a parent cell divides into two daughter cells.The cell cortex,a thin layer primarily composed of actin filaments and myosin motors beneath the plasma membrane,plays a critical role in ensuring proper cell division.In this study,we apply a hydrodynamic model to describe the actin cortex as an active nematic surface,incorporating orientational order arising from actin filament alignment and anisotropic active stress produced by myosin motors.By analyzing the linearized dynamics,we investigate how shape,flow,and stress regulators evolve over time when the surface deviates slightly from a sphere.Our findings reveal that the active alignment of actin filaments,often overlooked in previous studies,is crucial for successful division.Furthermore,we demonstrate that a cortical chiral flow naturally emerges as a consequence of this active alignment.Overall,our results provide a mechanistic explanation for key phenomena observed during cell division,offering new insights into the role of active stress and filament alignment in cortical dynamics.展开更多
A mutation in oxysterol-binding protein-like 2(OSBPL2)has been identified as the genetic cause of autosomal dominant nonsyndromic hearing loss(DFNA67,Online Mendelian Inheritance in Man No.616340).However,the pathogen...A mutation in oxysterol-binding protein-like 2(OSBPL2)has been identified as the genetic cause of autosomal dominant nonsyndromic hearing loss(DFNA67,Online Mendelian Inheritance in Man No.616340).However,the pathogenesis of the OSBPL2 mutation in DFNA remains unclear.Our previous work showed that Osbpl2 deficiency impaired cell adhesion in auditory HEI-OC1 cells.In addition,loss of hair cells(HCs)and morphological abnormalities of HC stereocilia were detected in OSBPL2-knockout pigs,suggesting that OSBPL2 plays an important role in regulating the actin cytoskeleton in auditory cells.In the present study,we found that Osbpl2 deficiency inhibited the Rho/ROCK2 signaling pathway and downregulated phosphorylated ezrin-radixinmoesin(p-ERM),resulting in abnormal F-actin morphology in HEI-OC1 cells and stereociliary defects in mouse HCs.The present study demonstrates the underlying mechanism of OSBPL2 in regulating the actin cytoskeleton in HCs,contributing to a deeper understanding of the pathogenesis of OSBPL2 mutations in DFNA.展开更多
目的:观察心脏营养素-1(CT-1)慢性作用所诱导的小鼠重构心肌中,肌小节收缩性蛋白α-Actin、细胞骨架蛋白α-Actinin及线粒体解偶联蛋白-2(UCP2)的表达情况。方法:实验组昆明小鼠腹腔注射CT-1C末端肽(carboxy-terminal polypeptide of ca...目的:观察心脏营养素-1(CT-1)慢性作用所诱导的小鼠重构心肌中,肌小节收缩性蛋白α-Actin、细胞骨架蛋白α-Actinin及线粒体解偶联蛋白-2(UCP2)的表达情况。方法:实验组昆明小鼠腹腔注射CT-1C末端肽(carboxy-terminal polypeptide of cardiotrophin-1,CT-1-CP)1、2、3、4周(每组10只,雌雄各半)后,对照组小鼠(10只,雌雄各半)腹腔注射生理盐水4周后,摘取小鼠心脏标本,石蜡包埋,切5μm厚切片,采用SABC检测肌小节结构蛋白α-Actin、α-Actinin与UCP2在小鼠心肌中的表达情况;同时采用Western blot检测小鼠心肌组织中3种蛋白质的相对表达量。结果:免疫组化结果显示,α-Actin的阳性颗粒主要集中于细胞核的周围,α-Actinin则趋于向肌节的横纹处汇聚,而UCP2则较均匀地散布于肌细胞浆中。结合Western blot相对灰度的比较分析,在对照组,α-Actin的表达水平略高于α-Actinin和UCP2,但3者之间并无明显的差异(WB:F=0.249,P>0.05)。注射CT-1-CP后,α-Actin的表达基本呈逐渐减弱的趋势,但对照组与4个注射组之间并无明显差异(χ2=7.386,P>0.05);与之相反,α-Actinin的表达则呈逐渐增强的趋势,阳性细胞数的百分比和阳性颗粒的染色强度都逐渐增多,而且各组间呈现出明显差异(χ2=21.977,P<0.01);UCP2的表达则在1周后增强,2周后达最高值,随后出现降低,4周后降至接近对照组的水平。结论:CT-1-CP的慢性作用可导致肌小节不同结构蛋白的比例发生改变,α-Actin的表达减少,α-Actinin的表达增多;而线粒体UCP2的表达达到一定峰值后即开始降低。展开更多
Plastins are a family of actin binding proteins （ABPs） known to cross-link actin microfilaments in mammalian cells, creating actin microfilament bundles necessary to confer cell polarity and cell shape. Plastins als...Plastins are a family of actin binding proteins （ABPs） known to cross-link actin microfilaments in mammalian cells, creating actin microfilament bundles necessary to confer cell polarity and cell shape. Plastins also support cell movement in response to changes in environment, involved in cell/tissue growth and development. They also confer plasticity to cells and tissues in response to infection or other pathological conditions （e.g., inflammation）. In the testis, the cell-cell anchoring junction unique to the testis that is found at the Sertoli cell-cell interface at the blood-testis barrier （BTB） and at the Sertoli-spermatid （e.g., 8-19 spermatids in the rat testis） is the basal and the apical ectoplasmic specialization （ES）, respectively. The ES is an F-actin-rich anchoring junction constituted most notably by actin microfilament bundles. A recent report using RNAi that specifically knocks down plastin 3 has yielded some insightful information regarding the mechanism by which plastin 3 regulates the status of actin microfilament bundles at the ES via its intrinsic actin filament bundling activity. Herein, we provide a brief review on the role of plastins in the testis in light of this report, which together with recent findings in the field, we propose a likely model by which plastins regulate ES function during the epithelial cycle of sDermatogenesis via their intrinsic activity on actin microfilament organization in the rat testis.展开更多
利用SMART(switching mechanismat5’end of RNA transcript)技术,提取果实少量总RNA,经15-25轮LD-PCR扩增获得全长ds-cDNA,构建了海南主栽的食用香蕉巴西蕉(Musa AAA Group Cavendish)果实的cDNA文库。所构建的文库容量为5×106Pfu...利用SMART(switching mechanismat5’end of RNA transcript)技术,提取果实少量总RNA,经15-25轮LD-PCR扩增获得全长ds-cDNA,构建了海南主栽的食用香蕉巴西蕉(Musa AAA Group Cavendish)果实的cDNA文库。所构建的文库容量为5×106Pfuml-1,重组率93%。利用此cDNA文库,采用96孔板PCR法筛选香蕉Actin2基因,测序结果显示,序列全长1723bp,编码区长1134bp,编码378个氨基酸,与蝴蝶兰Actin2基因序列同源率达83%,已递交GenBank,接受号692696。展开更多
【目的】分析13种植物actin基因的密码子组成、密码子偏性及聚类关系,了解其密码子使用模式及影响密码子使用的因素,为深入研究分子进化及物种进化提供参考。【方法】运用Codon W 1.4.4软件分析13种植物的肌动蛋白基因（actin）密码子...【目的】分析13种植物actin基因的密码子组成、密码子偏性及聚类关系,了解其密码子使用模式及影响密码子使用的因素,为深入研究分子进化及物种进化提供参考。【方法】运用Codon W 1.4.4软件分析13种植物的肌动蛋白基因（actin）密码子组成及使用参数,并对影响密码子偏性的因素进行研究。应用MEGA 4.1对13条基因的CDS序列进行聚类分析,采用SPSS 20.0进行密码子偏性的聚类分析。【结果】双子叶植物中actin基因的GC含量为45.0%～51.2%、GC3s含量为36.3%～53.8%,单子叶植物中GC含量为53.0%～58.3%、GC3s含量为60.9%～75.8%;actin基因在单子叶植物中偏爱G/C结尾的密码子,双子叶植物中偏爱A/T结尾的密码子。GC和GC3s与有效密码子数（ENC）呈极显著负相关（P〈0.01）,相关系数均为-0.906。ENC绘图分析结果表明,actin基因密码子偏性同时受突变和选择压力影响,单子叶植物受选择压力影响的程度大于双子叶植物。基于actin基因密码子偏性的聚类将单子叶植物高粱、玉米聚为一类,水稻、大麦、竹聚为一类,8种双子叶植物聚为一类。【结论】actin基因密码子偏性与碱基组成密切相关,其密码子偏性在单、双子叶植物间存在差异,依据密码子偏性的聚类能在一定程度上反映物种间的亲缘关系。展开更多
基金supported by the National Natural Science Foundation of China(32120103008)the National Key Research and Development Program of China(2023YFD1901700-3)+3 种基金Fundamental Research Funds for the Central Universities(2662024JC011,2662025HXPY005)the HZAU-AGIS Fund(SZYJY2021008)the Key Research and Development Projects of Henan province(231111113000)the Hubei Agricultural Science and Technology Innovation Center Program(2021-620-000-001-032).
文摘Alkaline stress in saline soil limits cotton production that may be improved by using emerging nanobiotechnology approaches.Here,we applied poly acrylic acid coated Mn3O4 nanoparticles(PMO)on cotton leaves which showed higher chlorophyll content(up to 100.0%)and fresh weight(46.9%)and lower electrolyte leakage rate(up to 6.8%)and cell death rate(up to 84.8%)than controls.Further investigation showed that PMO can maintain reactive oxygen species(ROS)homeostasis,increase the stability of actin filament(AF),and reduce Na^(+)content.Confocal imaging and ROS content measurement showed that PMO foliar application effectively alleviated ROS over-accumulation(up to 16.4%decrease for H_(2)O_(2)and 45.3%decrease for O_(2)^(•-))in cotton leaves.Moreover,under alkaline stress,genes for AF depolymerization such as GhADF1/8 and GhADF6 and for AF polymerization such as GhADF5 were significantly down-regulated in PMO treated cotton lines relative to those in the control,consistent with the fluorescence intensities of AFs.Furthermore,our results showed that PMO mitigated Na^(+)toxicity under alkaline stress,as indicated by the reduced Na^(+)fluorescence intensity and Na^(+)content.Furthermore,relative to those of the control,PMO treatment increased seed yield and lint yield by 65.0%and 66.3%respectively.Together,our work demonstrates that ROS scavenging PMO alleviated alkaline stress by stabilizing actin filaments and reducing Na^(+)toxicity.
基金support from the National Nat-ural Science Foundation of China(Grant No.12474199)the Fundamental Research Funds for Central Universities of China(Grant No.20720240144),and 111 Project(B16029).
文摘Cell division is a fundamental biological process in which a parent cell divides into two daughter cells.The cell cortex,a thin layer primarily composed of actin filaments and myosin motors beneath the plasma membrane,plays a critical role in ensuring proper cell division.In this study,we apply a hydrodynamic model to describe the actin cortex as an active nematic surface,incorporating orientational order arising from actin filament alignment and anisotropic active stress produced by myosin motors.By analyzing the linearized dynamics,we investigate how shape,flow,and stress regulators evolve over time when the surface deviates slightly from a sphere.Our findings reveal that the active alignment of actin filaments,often overlooked in previous studies,is crucial for successful division.Furthermore,we demonstrate that a cortical chiral flow naturally emerges as a consequence of this active alignment.Overall,our results provide a mechanistic explanation for key phenomena observed during cell division,offering new insights into the role of active stress and filament alignment in cortical dynamics.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.82071052 to J.Y.and 81771000 to X.C.)。
文摘A mutation in oxysterol-binding protein-like 2(OSBPL2)has been identified as the genetic cause of autosomal dominant nonsyndromic hearing loss(DFNA67,Online Mendelian Inheritance in Man No.616340).However,the pathogenesis of the OSBPL2 mutation in DFNA remains unclear.Our previous work showed that Osbpl2 deficiency impaired cell adhesion in auditory HEI-OC1 cells.In addition,loss of hair cells(HCs)and morphological abnormalities of HC stereocilia were detected in OSBPL2-knockout pigs,suggesting that OSBPL2 plays an important role in regulating the actin cytoskeleton in auditory cells.In the present study,we found that Osbpl2 deficiency inhibited the Rho/ROCK2 signaling pathway and downregulated phosphorylated ezrin-radixinmoesin(p-ERM),resulting in abnormal F-actin morphology in HEI-OC1 cells and stereociliary defects in mouse HCs.The present study demonstrates the underlying mechanism of OSBPL2 in regulating the actin cytoskeleton in HCs,contributing to a deeper understanding of the pathogenesis of OSBPL2 mutations in DFNA.
文摘Plastins are a family of actin binding proteins （ABPs） known to cross-link actin microfilaments in mammalian cells, creating actin microfilament bundles necessary to confer cell polarity and cell shape. Plastins also support cell movement in response to changes in environment, involved in cell/tissue growth and development. They also confer plasticity to cells and tissues in response to infection or other pathological conditions （e.g., inflammation）. In the testis, the cell-cell anchoring junction unique to the testis that is found at the Sertoli cell-cell interface at the blood-testis barrier （BTB） and at the Sertoli-spermatid （e.g., 8-19 spermatids in the rat testis） is the basal and the apical ectoplasmic specialization （ES）, respectively. The ES is an F-actin-rich anchoring junction constituted most notably by actin microfilament bundles. A recent report using RNAi that specifically knocks down plastin 3 has yielded some insightful information regarding the mechanism by which plastin 3 regulates the status of actin microfilament bundles at the ES via its intrinsic actin filament bundling activity. Herein, we provide a brief review on the role of plastins in the testis in light of this report, which together with recent findings in the field, we propose a likely model by which plastins regulate ES function during the epithelial cycle of sDermatogenesis via their intrinsic activity on actin microfilament organization in the rat testis.
文摘利用SMART(switching mechanismat5’end of RNA transcript)技术,提取果实少量总RNA,经15-25轮LD-PCR扩增获得全长ds-cDNA,构建了海南主栽的食用香蕉巴西蕉(Musa AAA Group Cavendish)果实的cDNA文库。所构建的文库容量为5×106Pfuml-1,重组率93%。利用此cDNA文库,采用96孔板PCR法筛选香蕉Actin2基因,测序结果显示,序列全长1723bp,编码区长1134bp,编码378个氨基酸,与蝴蝶兰Actin2基因序列同源率达83%,已递交GenBank,接受号692696。
文摘【目的】分析13种植物actin基因的密码子组成、密码子偏性及聚类关系,了解其密码子使用模式及影响密码子使用的因素,为深入研究分子进化及物种进化提供参考。【方法】运用Codon W 1.4.4软件分析13种植物的肌动蛋白基因（actin）密码子组成及使用参数,并对影响密码子偏性的因素进行研究。应用MEGA 4.1对13条基因的CDS序列进行聚类分析,采用SPSS 20.0进行密码子偏性的聚类分析。【结果】双子叶植物中actin基因的GC含量为45.0%～51.2%、GC3s含量为36.3%～53.8%,单子叶植物中GC含量为53.0%～58.3%、GC3s含量为60.9%～75.8%;actin基因在单子叶植物中偏爱G/C结尾的密码子,双子叶植物中偏爱A/T结尾的密码子。GC和GC3s与有效密码子数（ENC）呈极显著负相关（P〈0.01）,相关系数均为-0.906。ENC绘图分析结果表明,actin基因密码子偏性同时受突变和选择压力影响,单子叶植物受选择压力影响的程度大于双子叶植物。基于actin基因密码子偏性的聚类将单子叶植物高粱、玉米聚为一类,水稻、大麦、竹聚为一类,8种双子叶植物聚为一类。【结论】actin基因密码子偏性与碱基组成密切相关,其密码子偏性在单、双子叶植物间存在差异,依据密码子偏性的聚类能在一定程度上反映物种间的亲缘关系。
