Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction...Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.展开更多
The safety assessment of probiotic strains is crucial before their application in food or pharmaceuticals.While traditional phenotypic methods provide initial safety insights,they must be complemented by genomic analy...The safety assessment of probiotic strains is crucial before their application in food or pharmaceuticals.While traditional phenotypic methods provide initial safety insights,they must be complemented by genomic analysis to identify potential risks at the molecular level.This study aimed to conduct a comprehensive safety evaluation of Lactiplantibacillus plantarum TSP05,a potential probiotic isolated from pickle,using whole genome sequence analysis,functional gene annotation and phenotypic analysis.Whole genome sequencing was employed to screen for antibiotic resistance genes,virulence factors,and metabolic pathways,while phenotypic assays assessed hemolytic activity,antibiotic susceptibility,and metabolite production.Results demonstrated that TSP05 ex-hibitsα-hemolysis withoutβ-hemolytic activity,carries chromosomally encoded antibiotic resistance genes with no associated mobile genetic elements,produces no detectable biogenic amines,and generates D-lactate without the genetic mechanism for its conversion to toxic methylglyoxal.These findings confirm that L.plantarum TSP05 meets key safety criteria for probiotic use.Importantly,this study underscores the necessity of integrating genomic data with phenotypic profiling to achieve a robust and predictive safety assessment,aligning with modern regulatory guidelines.展开更多
The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like canc...The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem cells.To address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast cancer.The key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like phenotype.Highly sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse model.Overall,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies.展开更多
Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-...Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-up data of 146 patients with MMBC from Jan.2009to Dec.2009 treated in Tumor Hospital Affiliated to Zhengzhou University were retrospectively analyzed.展开更多
The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and ...The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and phenotype detection robots were discussed in this article.Further,the structural characteristics and information interaction modes of the current phenotype detection robots were summarized from the viewpoint of agriculture and forestry.The publications with keywords related to clustering distribution were analyzed and the currently available phenotype robots were classified.Additionally,a conclusion on the design criteria and evaluation system of plant phenotype detection robots was summarized and obtained,and the challenges and future development direction were proposed,which can provide a reference for the design and applications of agriculture and forestry robots.展开更多
Foodborne pathogens are subjected to various stress conditions such as those found in food environments and those applied as bactericidal processes.These diverse stress conditions can significantly influence the survi...Foodborne pathogens are subjected to various stress conditions such as those found in food environments and those applied as bactericidal processes.These diverse stress conditions can significantly influence the survival,adaptation,and virulence of pathogens in food systems.It is widely recognized that foodborne pathogens adapt to these conditions by increasing their resistance.Given that foodborne pathogens frequently contaminate food samples and are exposed to these stress conditions,understanding how these pathogens respond to such stresses is crucial.This review delves into the different aspects of foodborne pathogens encountering low temperature,osmotic stress,acidic stress,oxidative stress,and bactericidal treatments.Emphasis is placed on recent advances in transcriptomic analysis,particularly RNA sequencing,which has emerged as a powerful tool for elucidating global gene expression changes during stress adaptation.Even though RNA sequencing has been widely used in recent studies,meticulous experimental setup is essential for conducting such research.One of the challenges in studying the stress response of foodborne pathogens lies in the variation of response among strains.While certain genes may commonly express under specific stress conditions,generalizing this pattern proves difficult as complex factors also influence the phenomena.Furthermore,this review highlights the interplay between transcriptomic changes and phenotypic outcomes,underscoring the need for integrated multi-omics approaches to fully understand stress adaptation mechanisms.Hence,more refined and extensive experiments are warranted to gain a deeper understanding of the stress response exhibited by foodborne pathogens.展开更多
With the increasing demand for diversified health,the characteristic probiotics species resources need to be expanded.Here,a novel marine multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 was identified fro...With the increasing demand for diversified health,the characteristic probiotics species resources need to be expanded.Here,a novel marine multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 was identified from marine mangrove.Based on the characterization of probiotic properties in vivo and in vitro,the yeast could assimilate multiple carbon sources,and generate volatile flavor metabolites,achieved a 79.98%cholesterol removal rate with efficient in vivo survival and adhesion capabilities,and showed a strong antioxidant capacity.HJ2 also released hydrolase and fermented dietary fiber to yield SCFAs,contributing to disease prevention and treatment.Then,the safety was assessed according to phenotype and whole genome-sequencing analysis.No virulence genes or ARGs were annotated in the HJ2 genome.A few biogenic amines(BA)-related genes were observed,but the production of various BA and total BA were far below the food-defined thresholds.HJ2 did not produce virulence enzymes such as DNase,phospholipase,gelatinase,or coagulase,and exhibited sensitivity to amphotericin B and anidulafungin withoutβ-hemolysis.An in vivo acute toxicity test conducted on mice demonstrated that HJ2 is safe.In conclusion,HJ2 could be considered safe and be further used as a potential probiotic candidate for further clinical trials.展开更多
文摘Glycidyl methaerylate (GMA) is a recently recognized chemical mutagen. In order to explore the mutagenicity and mutagenic process of GMA, plasmid pBR322 was used for in vitro binding, mutant screening, and restriction enzyme mapping. The binding between GMA and DNA in vitro has been verified by means of a spectrophotometric method. When pBR322 and GMAbound pBR322 were used to transform Eschenchia coli HB101, the following results were obtained: (1) The transformation efficiency of GMA-bound pBR322 was much lower than that of pBR322 alone. (2) GMA-bound pBR322 induced phenotype changes in competent cells (i.e., tetracycline-resistance inactivation or ampicillin-resistance inactivation). There were two mutants of pBR322, Ap~RTc~S and Ap~STc~R, in the transformants and a deductive mutant Ap~STc~S in the nontranstormants. (3) All of the selected mutants were stable and heritable. (4) When restriction enzyme maps were used to analyze the mutant Ap~RTc~S, four of seven maps were changed. some sites were shifted to other resistant gene regions, for example, sites of Bgll, EcoRl, Ilindlll. Hinclll, etc., and there was a new recognition site for Hindi (252). We did not observe any DNA fragment insertion or deletion on any maps. Our results suggest that when GMA is covalently linked to the plasmid DNA, it gives rise to a premutagenic lesion of DNA that is converted in vivo into a point mutation. (C)1990 Academic Press, Inc.
基金supported by the Hunan Provincial Key Research and Development Program(Grant No.2023NK2035)Innovation and Entrepreneurship Talents Program of Jiangsu Province(Enterprise Innovation Categoty,Grant No.JSSCRC2023500).
文摘The safety assessment of probiotic strains is crucial before their application in food or pharmaceuticals.While traditional phenotypic methods provide initial safety insights,they must be complemented by genomic analysis to identify potential risks at the molecular level.This study aimed to conduct a comprehensive safety evaluation of Lactiplantibacillus plantarum TSP05,a potential probiotic isolated from pickle,using whole genome sequence analysis,functional gene annotation and phenotypic analysis.Whole genome sequencing was employed to screen for antibiotic resistance genes,virulence factors,and metabolic pathways,while phenotypic assays assessed hemolytic activity,antibiotic susceptibility,and metabolite production.Results demonstrated that TSP05 ex-hibitsα-hemolysis withoutβ-hemolytic activity,carries chromosomally encoded antibiotic resistance genes with no associated mobile genetic elements,produces no detectable biogenic amines,and generates D-lactate without the genetic mechanism for its conversion to toxic methylglyoxal.These findings confirm that L.plantarum TSP05 meets key safety criteria for probiotic use.Importantly,this study underscores the necessity of integrating genomic data with phenotypic profiling to achieve a robust and predictive safety assessment,aligning with modern regulatory guidelines.
基金the National Natural Science Foundation of China(grant nos.81972799 and 81871449)the Natural Science Foundation of Shanghai(grant no.23ZR1421400).
文摘The cancer stem cell hypothesis provides a basis for prediction of the recurrence and risk of metastasis in breast cancer.However,the unique expression pattern of stemness markers and the presence of nonstem-like cancer cells with varied phenotypes have brought great challenges to the characterization of breast cancer stem cells.To address these challenges,a phenotype-directed DNA nanomachine has been designed for high-accuracy labeling and in situ analysis of the stem cell-like subpopulation in breast cancer.The key for the design is to use cell surfaceanchored inputs to activate the nanomachine,which undergoes different branch migration pathways such that the signal strand can only be brought onto the cancer cells having the stem cell-like phenotype.Highly sensitive determination and single-step isolation of the stem cell-like subpopulation were achieved by incorporating functional groups into the signal strand such that the nanomachine was successfully applied in a tumor-bearing mouse model.Overall,the approach provides for a substantial improvement in capability for the analysis of the breast cancer stem cell-like subpopulation,and it is expected that the new approach will advance the use of DNA nanomachines in cancer-related studies.
文摘Objective This study was designed to investigate the prognostic implications of the intertumoral heterogeneity of molecular phenotype in multifocal and multicentric breast cancer(MMBC).Methods The clinical and follow-up data of 146 patients with MMBC from Jan.2009to Dec.2009 treated in Tumor Hospital Affiliated to Zhengzhou University were retrospectively analyzed.
基金funded by the Construction of Collaborative Innovation Center of Beijing Academy of Agricultural and Forestry Sciences(KJCX201917)Beijing Nova Program(Z211100002121065)Science and Technology Innovation Special Construction Funded Program of Beijing Academy of Agriculture and Forestry Sciences(KJCX20210413).
文摘The continuous development of robot technology has made phenotype detection robots a key for extracting and analyzing phenotyping data in agriculture and forestry.The different applications of agricultural robots and phenotype detection robots were discussed in this article.Further,the structural characteristics and information interaction modes of the current phenotype detection robots were summarized from the viewpoint of agriculture and forestry.The publications with keywords related to clustering distribution were analyzed and the currently available phenotype robots were classified.Additionally,a conclusion on the design criteria and evaluation system of plant phenotype detection robots was summarized and obtained,and the challenges and future development direction were proposed,which can provide a reference for the design and applications of agriculture and forestry robots.
文摘Foodborne pathogens are subjected to various stress conditions such as those found in food environments and those applied as bactericidal processes.These diverse stress conditions can significantly influence the survival,adaptation,and virulence of pathogens in food systems.It is widely recognized that foodborne pathogens adapt to these conditions by increasing their resistance.Given that foodborne pathogens frequently contaminate food samples and are exposed to these stress conditions,understanding how these pathogens respond to such stresses is crucial.This review delves into the different aspects of foodborne pathogens encountering low temperature,osmotic stress,acidic stress,oxidative stress,and bactericidal treatments.Emphasis is placed on recent advances in transcriptomic analysis,particularly RNA sequencing,which has emerged as a powerful tool for elucidating global gene expression changes during stress adaptation.Even though RNA sequencing has been widely used in recent studies,meticulous experimental setup is essential for conducting such research.One of the challenges in studying the stress response of foodborne pathogens lies in the variation of response among strains.While certain genes may commonly express under specific stress conditions,generalizing this pattern proves difficult as complex factors also influence the phenomena.Furthermore,this review highlights the interplay between transcriptomic changes and phenotypic outcomes,underscoring the need for integrated multi-omics approaches to fully understand stress adaptation mechanisms.Hence,more refined and extensive experiments are warranted to gain a deeper understanding of the stress response exhibited by foodborne pathogens.
基金supported by the Funding Project of Chinese Central Government Guiding to the Guangxi Local Science and Technology Development[Grant No.GUIKEZY21195021]the Natural Science Fund for Distinguished Young Scholars of Guangxi Zhuang Autonomous Region of China[Grant No.2019GXNSFFA245011]+2 种基金the Funding Project of Chinese Central Government Guiding to the Nanning Local Science and Technology Development[Grant No.20231012]the Funding Project of Technological Development from Angel Yeast[Chongzuo]Co.,Ltd.[Grant No.JS1006020230722019]the Basic Research Fund of Guangxi Academy of Sciences[Grant No.CQ-C-202202].
文摘With the increasing demand for diversified health,the characteristic probiotics species resources need to be expanded.Here,a novel marine multi-stress-tolerant aromatic yeast Pichia kudriavzevii HJ2 was identified from marine mangrove.Based on the characterization of probiotic properties in vivo and in vitro,the yeast could assimilate multiple carbon sources,and generate volatile flavor metabolites,achieved a 79.98%cholesterol removal rate with efficient in vivo survival and adhesion capabilities,and showed a strong antioxidant capacity.HJ2 also released hydrolase and fermented dietary fiber to yield SCFAs,contributing to disease prevention and treatment.Then,the safety was assessed according to phenotype and whole genome-sequencing analysis.No virulence genes or ARGs were annotated in the HJ2 genome.A few biogenic amines(BA)-related genes were observed,but the production of various BA and total BA were far below the food-defined thresholds.HJ2 did not produce virulence enzymes such as DNase,phospholipase,gelatinase,or coagulase,and exhibited sensitivity to amphotericin B and anidulafungin withoutβ-hemolysis.An in vivo acute toxicity test conducted on mice demonstrated that HJ2 is safe.In conclusion,HJ2 could be considered safe and be further used as a potential probiotic candidate for further clinical trials.
