期刊文献+
共找到29,741篇文章
< 1 2 250 >
每页显示 20 50 100
Cloning of Ln Gene Through Combined Approach of Map-based Cloning and Association Study in Soybean 被引量:12
1
作者 Chao Fang Weiyu Li +9 位作者 Guiquan Li Zheng Wang Zhengkui Zhou Yanming Ma Yanting Shen Congcong Li Yunshuai Wu Baoge Zhu Weicai Yang Zhixi Tian 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2013年第2期93-96,共4页
Increasing yield is one of the most important goals in crop breeding. Soybean (Glycine max L. Merr.), one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more t... Increasing yield is one of the most important goals in crop breeding. Soybean (Glycine max L. Merr.), one of the most economically important leguminous seed crops, provides the majority of plant proteins, and more than a quarter of the world's food and animal feed (Graham and Vance, 2003). The yield of soybean is finally determined by the number of seeds per unit area, which affected by many characters, such as height, branching number, photosynthesis, seed size, seed number. The number of seeds per pod is taken for one of the critical components that related to yield (You et al., 1995). 展开更多
关键词 cloning of Ln Gene Through Combined Approach of map-based cloning and Association Study in Soybean GENE
原文传递
3-34 Gene Mining: Association Analysis of the Whole Genome Re-sequencing and the Map-based Cloning
2
作者 Du Yan Zhou Libin +5 位作者 Yu Lixia Luo Shanwei Feng Hui Mu Jinhu Chen Yuze Li Wenjian 《IMP & HIRFL Annual Report》 2015年第1期130-131,共2页
Since the whole genome sequence of Arabidopsis thaliana ecotype Columbia (Col-0) was published in 2 000, the focus of genomics study had turned from structural genomics to functional genomics era[1]. In the post genom... Since the whole genome sequence of Arabidopsis thaliana ecotype Columbia (Col-0) was published in 2 000, the focus of genomics study had turned from structural genomics to functional genomics era[1]. In the post genomics era, mutants play an important role for gene function exploring. Therefore, acquiring various variants and studying on them are useful for understanding the mechanism of plant development and molecular design for plant breeding. 展开更多
关键词 map-based cloning ASSOCIATION
在线阅读 下载PDF
Map-based cloning of the ALK gene,which controls the gelatinization temperature of rice 被引量:37
3
作者 高振宇 曾大力 +5 位作者 崔霞 周奕华 颜美仙 黄大年 李家洋 钱前 《Science China(Life Sciences)》 SCIE CAS 2003年第6期661-668,共8页
Gelatinization temperature (GT) is an important parameter for evaluating the cooking and eating quality of rice besides amylose content (AC). The inheritance of the genes affecting GT has been widely studied and is co... Gelatinization temperature (GT) is an important parameter for evaluating the cooking and eating quality of rice besides amylose content (AC). The inheritance of the genes affecting GT has been widely studied and is considered to be controlled by a major gene. Here, we report the map-based cloning of rice ALK that encodes the soluble starch synthase II (SSSII). Comparison between the DNA sequences from different rice varieties, together with the results obtained with digestion of the rice seeds in alkali solution, indicates that the base substitutions in coding se-quence of ALK may cause the alteration in GT. 展开更多
关键词 rice (Oryza sativa L.) ALK soluble starch synthase II gelatinization temperature map-based cloning.
原文传递
Map-Based Cloning of zb7 Encoding an IPP and DMAPP Synthase in the MEP Pathway of Maize 被引量:9
4
作者 Xiao-Min LU Xiao-Jiao Hu +7 位作者 Yuan-Zeng Zhao Wei-Bin Song Mei Zhang Zong-Liang Chen Wei Chen Yong-Bin Dong Zhen-Hua Wang Jin-Sheng Lai 《Molecular Plant》 SCIE CAS CSCD 2012年第5期1100-1112,共13页
IspH is a key enzyme in the last step of the methyI-D-erythritol-4-phosphate (MEP) pathway. Loss of function of IspH can often result in complete yellow or albino phenotype in many plants. Here, we report the charac... IspH is a key enzyme in the last step of the methyI-D-erythritol-4-phosphate (MEP) pathway. Loss of function of IspH can often result in complete yellow or albino phenotype in many plants. Here, we report the characterization of a recessive mutant of maize, zebra7 (zb7), showing transverse green/yellow striped leaves in young plants. The yellow bands of the mutant have decreased levels of chlorophylls and carotenoids with delayed chloroplast development. Low temperature suppressed mutant phenotype, while alternate light/dark cycle or high temperature enlarged the yellow section. Map-based cloning demonstrated that zb7 encodes the IspH protein with a mis-sense mutation in a conserved region. Transgenic silencing of Zb7 in maize resulted in complete albino plantlets that are aborted in a few weeks, confirming that Zb7 is important in the early stages of maize chloroplast development. Zb7 is constitutively expressed and its expression subject to a 16-h light/8-h dark cycle regulation. Our results suggest that the less effective or unstable IspH in zb7 mutant, together with its diurnal expression, are mechanistically accounted for the zebra phenotype. The increased IspH mRNA in the leaves of zb7 at the late development stage may explain the restoration of mutant phenotype in mature stages. 展开更多
关键词 zb7 mutant CHLOROPLAST IspH RNAi map-based cloning.
原文传递
Economical phase-covariant cloning with multiclones 被引量:1
5
作者 张文海 叶柳 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期3702-3705,共4页
This paper presents a very simple method to derive the explicit transformations of the optimal economical 1 to M phase-covariant cloning. The fidelity of clones reaches the theoretic bound [D'Ar]ano G M and Macchiave... This paper presents a very simple method to derive the explicit transformations of the optimal economical 1 to M phase-covariant cloning. The fidelity of clones reaches the theoretic bound [D'Ar]ano G M and Macchiavello C 2003 Phys. Rev. A 67 042306]. The derived transformations cover the previous contributions [Delgado Y, Lamata Let al, 2007 Phys. Rev. Lett. 98 150502] in which M must be odd. 展开更多
关键词 quantum cloning economical phase-covariant cloning
原文传递
Scan matching using line segment relationships for map-based localization of mobile robot 被引量:1
6
作者 葛坤峰 陈卫东 +1 位作者 王景川 冉宇瑶 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第6期757-762,共6页
A new scan matching method for mobile robot localization is presented, which takes line segment as the feature and matches the real scans in the given reference map by relationships of the directional-defined line seg... A new scan matching method for mobile robot localization is presented, which takes line segment as the feature and matches the real scans in the given reference map by relationships of the directional-defined line segments. The alignment was done by hierarchically identifying the multiple relationships and the result was recorded in a correspondence matrix, where the best match is defined and selected for localization. It is indicated that the searching algorithm of the best match can find the ambiguities and get rid of them. This method with less computational cost works well in occluded environment, and can correct the error in pose estimation without the need for the estimation itself. The efficiency, accuracy and robustness of this method were verified by experiments of localization in an occluded environment and a long-distance indoor navigation. 展开更多
关键词 scan matching laser range finder map-based localization mobile robot
在线阅读 下载PDF
Map-based control method for vehicle stability enhancement 被引量:2
7
作者 Moon-Young Yoon Seung-Hwan Baek +1 位作者 Kwang-Suk Boo Heung-Seob Kim 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期114-120,共7页
This work proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-r... This work proposes a map-based control method to improve a vehicle's lateral stability, and the performance of the proposed method is compared with that of the conventional model-referenced control method. Model-referenced control uses the sliding mode method to determine the compensated yaw moment; in contrast, the proposed map-based control uses the compensated yaw moment map acquired by vehicle stability analysis. The vehicle stability region is calculated by a topological method based on the trajectory reversal method. A 2-DOF vehicle model and Pacejka's tire model are used to evaluate the proposed map-based control method. The properties of model-referenced control and map-based control are compared under various road conditions and driving inputs. Model-referenced control uses a control input to satisfy the linear reference model, and it generates unnecessary tire lateral forces that may lead to worse performance than an uncontrolled vehicle with step steering input on a road with a low friction coefficient. However, map-based control determines a compensated yaw moment to maintain the vehicle within the stability region,so the typical responses of vehicle enable to converge rapidly. The simulation results with sine and step steering show that map-based control provides better the tracking responsibility and control performance than model-referenced control. 展开更多
关键词 model-referenced control map-based control vehicle stability yaw moment
在线阅读 下载PDF
Superovulation of the Cloned Cattle Derived from Somatic Cells and the Transfer of the Vitrified-Thawed Embryos of the Cloning Cattle
8
作者 DONGYa-juan BAIXue-jin LIJian-dong CHENGMing 《Agricultural Sciences in China》 CAS CSCD 2004年第12期937-942,共6页
In this experiment, it was designed to carry out superovulation on the two cloned cattles, vitrification and transfer of the embryos recovered from them. First of all, it was carried out vitrification on embryos obt... In this experiment, it was designed to carry out superovulation on the two cloned cattles, vitrification and transfer of the embryos recovered from them. First of all, it was carried out vitrification on embryos obtained by IVF. Results showed that there were no significant differences between the blastocysts (obtained by IVF) vitrified in EPS10 and these in EPS20 on the resuscitative rate and the developmental rate. The hatched rate of the blastocysts vitrified in EPS10 (31.3%, 35/112) was significantly higher than that in EPS20 (12.2%, 13/107)(P<0.01), so EPS20 was selected as the vitrification solution to freeze the embryos recovered from the cloned cattle. After superovulation, six (four usable embryos) and ten (nine usable embryos) embryos were respectively recovered from Kangkang and Shuanghuang. Two embryos were selected from the recovered embryos of each cloned cattle to freeze in EPS20, subsequently thawed and transferred into luteal ipsilateral uterine horns of 4 Holstein recipient cows after synchronization of estrus, respectively. At last, one recipient cow (No. 9908) became pregnant and delivered one healthy calf (descendant of the cloned cattle-Shuangshuang). The results of this experi- ment show that the cloned cattle as well as common cattle had better response to the exotic FSH and better ability to multiovulation, the embryos recovered from the cloned cattle can be vitrificated. 展开更多
关键词 Cloned cattle SUPEROVULATION EMBRYO VITRIFICATION
在线阅读 下载PDF
MAP-based Audio Coding Compensation for Speaker Recognition
9
作者 Tao Jiang Jiqing Han 《Journal of Signal and Information Processing》 2011年第3期165-169,共5页
The performance of the speaker recognition system declines when training and testing audio codecs are mismatched. In this paper, based on analyzing the effect of mismatched audio codecs in the linear prediction cepstr... The performance of the speaker recognition system declines when training and testing audio codecs are mismatched. In this paper, based on analyzing the effect of mismatched audio codecs in the linear prediction cepstrum coefficients, a method of MAP-based audio coding compensation for speaker recognition is proposed. The proposed method firstly sets a standard codec as a reference and trains the speaker models in this codec format, then learns the deviation distributions between the standard codec format and the other ones, next gets the current bias via using a small number adaptive data and the MAP-based adaptive technique, and then adjusts the model parameters by the type of coming audio codec format and its related bias. During the test, the features of the coming speaker are used to match with the adjusted model. The experimental result shows that the accuracy reached 82.4% with just one second adaptive data, which is higher 5.5% than that in the baseline system. 展开更多
关键词 AUDIO CODING COMPENSATION SPEAKER RECOGNITION map-based
在线阅读 下载PDF
Transcription coactivator YAP1 promotes CCND1/CDK6 expression,stimulating cell proliferation in cloned cattle placentas 被引量:1
10
作者 Shan-Shan Wu Xiao-Yu Zhao +7 位作者 Lei Yang Chao Hai Di Wu Xue-Fei Liu Li-Shuang Song Chun-Ling Bai Guang-Hua Su Guang-Peng Li 《Zoological Research》 2025年第1期122-138,共17页
Somatic cell nuclear transfer(SCNT)has been successfully employed across various mammalian species,yet cloned animals consistently exhibit low pregnancy rates,primarily due to placental abnormalities such as hyperplas... Somatic cell nuclear transfer(SCNT)has been successfully employed across various mammalian species,yet cloned animals consistently exhibit low pregnancy rates,primarily due to placental abnormalities such as hyperplasia and hypertrophy.This study investigated the involvement of the Hippo signaling pathway in aberrant placentaldevelopmentinSCNT-inducedbovine pregnancies.SCNT-derived cattle exhibited placental hypertrophy,including enlarged abdominal circumference and altered placental cotyledon morphology.RNA sequencing analysis indicated significant dysregulation of Hippo signaling pathway genes in SCNT placentas.Coexpression of YAP1 and CCND1 was observed in cloned blastocysts,placental tissues,and bovine placental mesenchymal stem cells(bPMSCs).Manipulation of YAP1expression demonstrated the capacity to regulate bPMSC proliferation.Experimental assays confirmed the direct binding of YAP1 to CCND1,which subsequently promoted CCND1 expression in bPMSCs.Furthermore,inhibition of CDK6,a downstream target of CCND1,attenuated SCNT bPMSC proliferation.This study identified YAP1 as a key regulatory component within the Hippo signaling pathway that drives placental hyperplasia in cloned cattle through up-regulation of CCND1-CDK6 expression,facilitating cell cycle progression.These findings offer potential avenues for enhancing cloning efficiency,with implications for evolutionary biology and the conservation of valuable germplasm resources. 展开更多
关键词 Somatic cell nuclear transfer Cloned cattle Placental hypertrophy Cell proliferation CCND1-CDK6 YAP1
在线阅读 下载PDF
Cloning scheme for multipartite entangled pure states via photonic quantum walk
11
作者 WANG Guocui LIN Zhi +2 位作者 LI Xikun YANG Qing YANG Ming 《量子电子学报》 北大核心 2025年第2期206-216,共11页
The no-cloning theorem has sparked considerable interest in achieving high-fidelity approximate quantum cloning.Most of the previous studies mainly focused on the cloning of single particle states,and cloning schemes ... The no-cloning theorem has sparked considerable interest in achieving high-fidelity approximate quantum cloning.Most of the previous studies mainly focused on the cloning of single particle states,and cloning schemes used there are incapable of cloning quantum entangled states in multipartite systems.Few schemes were proposed for cloning multiparticle states,which consume more entanglement resources with loss of qubits,and the fidelity of the cloned state is relatively low.In this paper,cloning schemes for bipartite and tripartite entangled states based on photonic quantum walk and entanglement swapping are proposed.The results show that according to the proposed schemes,two high-fidelity(up to 0.75)cloned states can be obtained with less quantum resource consumption.Because of the simple cloning steps,few quantum resources and high fidelity,these schemes are both efficient and feasible.Moreover,this cloning machine eliminates the need for tracing out cloning machine,thereby minimizing resource waste. 展开更多
关键词 quantum optics entanglement cloning photonic quantum walk multipartite entanglement
在线阅读 下载PDF
Comparative Analysis of Golden Gate and ClassicalCloning Techniques in E.coli:A Study in Molecular Cloning Efficiency
12
作者 Ziyao Liu 《Asia Pacific Journal of Clinical Medical Research》 2025年第2期29-38,共10页
Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate asse... Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate assembly technique,utilizing Escherichia coli as the model organism.Through polymerase chain reaction(PCR)amplification,restriction enzyme digestion,ligation,transformation,and Sanger sequencing,we assessed the operational efficiency and cloning fidelity of both strategies.Our results demonstrated that Golden Gate assembly,leveraging type IIS restriction enzymes and simultaneous ligation,significantly enhanced cloning efficiency and precision,particularly for seamless multi-fragment assembly.In contrast,the classical cloning approach maintained certain advantages in simplicity and robustness for specific experimental conditions.Challenges encountered during transformation and sequencing highlighted the critical impact of technical accuracy on experimental outcomes.This study underscores the importance of selecting appropriate cloning methodologies tailored to experimental objectives and laboratory capabilities,providing a foundation for optimized molecular cloning workflows in future synthetic biology and biotechnology applications. 展开更多
关键词 Golden Gate Assembly Classical cloning Escherichia Coli Molecular cloning DNA Assembly Recombinant DNA Technology Transformation Effi ciency Synthetic Biology
在线阅读 下载PDF
Cloning and Bioinformatics Analysis of trxB Gene in Vibrio alginolyticus HY9901
13
作者 Yuyan HE Xuelian LIN +3 位作者 Zhihang CHEN Xiaoxin WEN Jianyi WEI Huanying PANG 《Agricultural Biotechnology》 2025年第2期1-5,共5页
[Objectives]This study was conducted to investigate the functional characteristics of the trxB gene in Vibrio alginolyticus.[Methods]A pair of specific primers was designed based on the trxB gene sequence of V.alginol... [Objectives]This study was conducted to investigate the functional characteristics of the trxB gene in Vibrio alginolyticus.[Methods]A pair of specific primers was designed based on the trxB gene sequence of V.alginolyticus for PCR cloning of its full-length sequence.Systematic bioinformatics analyses were conducted to predict the physicochemical properties,secondary structure,and tertiary structure of the encoded protein.[Results]The trxB gene is 960 bp in length,encoding 319 amino acid residues.The deduced protein has a predicted molecular weight of 34.32 kDa and an isoelectric point(pI)of 4.77.Analysis of the amino acid sequence revealed a distinct signal peptide cleavage site at the N-terminus,with no transmembrane domains.The functional sites are as follows:1 N-glycosylation site,1 cAMP-and cGMP-dependent protein kinase phosphorylation site,4 protein kinase C phosphorylation sites,7 casein kinase II phosphorylation sites,1 tyrosine kinase phosphorylation site,11 N-myristoylation sites,1 prenyl group binding site,3 microbody C-terminal targeting signal sites,and 1 xanthine nucleotide-disulfide oxidoreductase class II active site.Subcellular localization prediction indicated the highest probability(44.4%)for endoplasmic reticulum localization.The TrxB amino acid sequence of V.alginolyticus shares 97.2%-98.4%homology with other Vibrio species,and they were clustered within the same subgroup.Secondary structure prediction showed proportions of random coils(31.97%),alpha-helices(31.66%),extended strands(25.08%),and beta turns(11.29%).The tertiary structure model exhibited 88.68%similarity to template 5vt3.1.A.[Conclusions]This study elucidated the characterization of the TrxB protein in V.alginolyticus,laying a theoretical foundation for the development of outer membrane protein subunit vaccines against this pathogen. 展开更多
关键词 Vibrio alginolyticus Gene cloning trxB gene Bioinformatics analysis
在线阅读 下载PDF
Cloning and Bioinformatics Analysis of cobQ Gene from Vibrio alginolyticus Strain HY9901
14
作者 Chao HUANG Zhihang CHEN +6 位作者 Weijie ZHANG Xiaoxin WEN Jiajie MA Peng ZHOU Yingying JIANG Huanying PANG 《Asian Agricultural Research》 2025年第4期19-23,共5页
[Objectives] To analyze the function of cobQ gene from Vibrio alginolyticus strain HY9901,and to provide a reference for exploring the possible mechanism of cobQ gene from V.alginolyticus.[Methods] A pair of primers w... [Objectives] To analyze the function of cobQ gene from Vibrio alginolyticus strain HY9901,and to provide a reference for exploring the possible mechanism of cobQ gene from V.alginolyticus.[Methods] A pair of primers were designed based on the sequence of the V.alginolyticus cobQ gene and used to amplify the full-length gene by PCR.[Results] The PCR amplification results indicated that the cobQ gene has a full length of 780 bp,encoding 259 amino acid residues.The deduced amino acid sequence predicts a molecular weight of approximately 28.83 kD and an isoelectric point of 9.21.Sequence analysis revealed no N-terminal signal peptide cleavage site,suggesting the absence of both a signal peptide and transmembrane regions in this protein.The amino acid sequence contains 2 N-terminal myristoylation sites,1 N-glycosylation site,1 glycosaminoglycan attachment site,4 microbody C-terminal targeting signal sites,3 casein kinase II phosphorylation sites,and 4 protein kinase C phosphorylation sites.Subcellular localization prediction showed that the CobQ protein is primarily localized in the cytoplasm(65.2%probability).Homology analysis demonstrated that the amino acid sequence of the cobQ gene from V.alginolyticus shares up to 99%homology with other Vibrio species,clustering within the same subclade as Vibrio parahaemolyticus,indicating close phylogenetic relationships.Secondary structure prediction revealed proportions ofα-helices,random coils,and extended strands as 44.40%,36.68%,and 18.92%,respectively.The tertiary structure model exhibited 87.62%similarity to the template A0A165XBE1.1.[Conclusions] In this study,the V.alginolyticus cobq gene was successfully cloned and its sequence was analyzed by bioinformatics.It is expected to lay a foundation for the subsequent study of the regulatory mechanism of its protein on the virulence of V.alginolyticus. 展开更多
关键词 Vibrio alginolyticus Gene cloning cobQ gene Bioinformatics analysis
在线阅读 下载PDF
Cloning and Expression Vector Construction of BnOPR1 from Brassica napus
15
作者 CHENG Yi-yuan YUAN Yu-hui +5 位作者 WANG Yan-hong GONG Sha LING Hui HUANG Jing-yi ZHONG Pin-tian LIU Xian-jun 《Agricultural Science & Technology》 2025年第3期6-14,共9页
The 12-oxophytodienoate reductase(OPR),a flavin mononucleotide-dependent oxidoreductase,regulates plant responses to stress conditions such as heavy metals,drought,saline-alkali,pests,and diseases by participating in ... The 12-oxophytodienoate reductase(OPR),a flavin mononucleotide-dependent oxidoreductase,regulates plant responses to stress conditions such as heavy metals,drought,saline-alkali,pests,and diseases by participating in the synthesis of plant hormones such as jasmonic acid(JA).In this study,homologous cloning was employed to obtain the Brassica napus‘Zhongshuang 11’OPR1 gene(BnOPR1).Bioinformatics analysis was conducted for the deduced protein BnOPR1,and a plant expression vector for BnOPR1 was constructed.The bioinformatics analysis revealed that BnOPR1 was 1125 bp in length,encoding 375 amino acid residues.The deduced protein had a molecular weight of 41.604 kDa,an isoelectric point of 6.05,a molecular formula of C1853H2855N511O550S16,an aliphatic index of 35.47,a lipophilicity index of 74.87,and an instability index of 39.49.It had 49 phosphorylation sites and lacked transmembrane domains and signal peptides.The phylogenetic analysis indicated that BnOPR1 had a close relationship with the OPR1 protein from Brassica rapa since they shared the same clade,while it had a distant relationship with the OPR1 protein from Raphanus sativus.In this paper,the expression vector for BnOPR1 was successfully constructed by seamless cloning and named pBnOPR1.The findings laid a foundation for further studying the roles of BnOPR1 in the response to antimony stress. 展开更多
关键词 Brassica napus BnOPR1 gene Homologous cloning Vector construction
在线阅读 下载PDF
Cloning of qHD8^(BAS),a Quantitative Trait Locus Regulating Heading Date in Rice
16
作者 ZHANG Zhengjiu BIAN Ying +3 位作者 YANG Ruoju ZHANG Xiaobo GONG Junyi FAN Jiongjiong 《Rice science》 2025年第3期283-286,I0005-I0011,共11页
Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD... Heading date is one of the most important agronomic traits that directly affect rice yield and determines the regional adaptability in specific growing environments.As a short-day plant,rice can grow under long-day(LD)conditions due to the synergistic regulation of many photosensitive genes.Using a set of chromosome segment substitution lines(CSSLs)with the indica cultivar Huanghuazhan(HHZ)as the recipient parent and Basmati Surkh 89-15(BAS)as the donor parent,we identified a QTL locus. 展开更多
关键词 chromosome segment substitution lines cssls agronomic traits identified qtl locus indica cultivar quantitative trait locus synergistic regulation many photosensitive genesusing heading date cloning
在线阅读 下载PDF
猫杯状病毒感染性克隆的构建及拯救病毒的鉴定
17
作者 朱雪敏 李鑫基 +7 位作者 华炯钢 陈柳 叶伟成 张传亮 朱寅初 付媛 张存 云涛 《中国兽医科学》 北大核心 2026年第1期20-26,共7页
旨在建立猫杯状病毒(FCV)反向遗传系统,以探究FCV的致病机制,为后续疫苗研发提供科学依据。以FCV HZ2024株为对象,构建DNA-launched感染性克隆系统。FCV全基因组的4个片段被依次插入pAY-CHS重组质粒后转染F81细胞并传代鉴定。结果显示,F... 旨在建立猫杯状病毒(FCV)反向遗传系统,以探究FCV的致病机制,为后续疫苗研发提供科学依据。以FCV HZ2024株为对象,构建DNA-launched感染性克隆系统。FCV全基因组的4个片段被依次插入pAY-CHS重组质粒后转染F81细胞并传代鉴定。结果显示,FCV HZ2024基因片段扩增后插入DNA-launched系统质粒,成功构建DNA-launched系统拯救病毒rFCV HZ2024-RE,转染细胞24 h后出现细胞病变效应,病毒滴度稳定在10^(7)~10^(8T)CID_(50)/m L。间接免疫荧光检测证实VP1蛋白抗原表位完全保留,重组病毒的衣壳蛋白成功表达。且重组病毒与亲本毒株的复制动力学高度相似,蚀斑形态无显著差异。Eco R V酶切及测序验证表明,突变位点(C7183T、A7186C)被精准引入且稳定遗传。总之,构建的DNA-launched系统实现了FCV高效拯救与精准遗传。 展开更多
关键词 猫杯状病毒 感染性克隆 反向遗传学 病毒拯救
在线阅读 下载PDF
土壤细菌16S rRNA基因实时荧光定量PCR标准品的制备及稳定性探究
18
作者 朱璧如 廖万金 徐冰 《生物学杂志》 北大核心 2026年第1期97-102,共6页
实时荧光定量PCR(qPCR)被越来越多地用于测量微生物的绝对数量,使用该方法的关键是制备合适的标准品并建立稳定的实验方案。本研究成功构建了一个含有土壤细菌16S rRNA基因全长的质粒标准品,该标准品可以被4对细菌16S rRNA基因的通用引... 实时荧光定量PCR(qPCR)被越来越多地用于测量微生物的绝对数量,使用该方法的关键是制备合适的标准品并建立稳定的实验方案。本研究成功构建了一个含有土壤细菌16S rRNA基因全长的质粒标准品,该标准品可以被4对细菌16S rRNA基因的通用引物扩增。使用其中2对引物进行绝对定量qPCR实验,熔解曲线均为单峰,标准曲线的扩增效率分别为87.4%和71.9%,拟合优度均大于0.99。1 d内使用同一套梯度稀释的标准品进行3次qPCR实验,使用TE或TE_(0.1)缓冲液进行稀释或4℃低温存放均能提高标准曲线扩增效率和拟合优度的稳定性。质粒标准品-20℃存放30 d后,标准曲线的扩增效率和拟合优度并未显著降低,但在不同时间测得的扩增效率有波动,使用TE或TE_(0.1)缓冲液进行标准品稀释可减小这种波动。保证标准品在存放和使用过程中的稳定性,有助于提高不同空间和时间进行绝对定量qPCR实验的准确性和复现性。 展开更多
关键词 绝对定量qPCR 质粒克隆 标准曲线 扩增效率 拟合优度
在线阅读 下载PDF
中华绒螯蟹ELOVL7基因克隆及功能验证
19
作者 杨志刚 叶晓龙 +3 位作者 陈阿琴 李腾 王爱民 耿明阳 《南方水产科学》 北大核心 2026年第1期199-208,共10页
长链脂肪酸延长酶(Elongation of long-chain fatty acids,ELOVL)在长链多不饱和脂肪酸(Long-chain polyunsaturated fatty acids,LC-PUFA)的生物合成中起关键作用。为探究中华绒螯蟹(Eriocheir sinensis)LC-PUFA的合成机制,采用cDNA末... 长链脂肪酸延长酶(Elongation of long-chain fatty acids,ELOVL)在长链多不饱和脂肪酸(Long-chain polyunsaturated fatty acids,LC-PUFA)的生物合成中起关键作用。为探究中华绒螯蟹(Eriocheir sinensis)LC-PUFA的合成机制,采用cDNA末端快速扩增(Rapidamplification of cDNA ends,RACE)技术克隆获得中华绒螯蟹ELOVL7基因。该基因cDNA全长序列为1600 bp,包含1个1200 bp的开放阅读框(Open reading frame,ORF),编码399个氨基酸,其5'非翻译区(5'-UTR)和3'-UTR长度分别为176和224 bp。ELOVL7具有典型的ELOVL结构,包括8个跨膜结构域、多个保守基序以及特征性的组氨酸盒(HXXHH)。氨基酸序列相似性比对分析显示,中华绒螯蟹ELOVL7与榄绿青蟹(Scylla olivacea)和三疣梭子蟹(Portunus trituberculatus)ELOVL7的氨基酸序列相似性较高,分别为73.82%和73.76%。系统进化树分析显示,中华绒螯蟹ELOVL7首先与榄绿青蟹和三疣梭子蟹ELOVL7聚为一支,进而与其他甲壳动物ELOVL7共同构成一个独立的甲壳类分支。基因组织表达分析显示,中华绒螯蟹ELOVL7基因在肠道组织中表达量最高,其次为鳃组织。为验证其功能,将中华绒螯蟹ELOVL7基因编码序列重组至pYES2载体,转化酿酒酵母(Saccharomyces cerevisiae)INVSc1菌株,成功构建了其酿酒酵母异源表达系统。酵母异源表达分析表明,ELOVL7能催化脂肪酸底物C18:1n-9延长为C20:1n-9。 展开更多
关键词 中华绒螯蟹 长链脂肪酸延长酶7 基因克隆 组织表达 酵母异源表达
在线阅读 下载PDF
长白落叶松无性系枝、叶性状分析与耐旱性评价
20
作者 张曦文 陈廷廷 +4 位作者 王福德 郭琪 杨伟财 卫星 谷加存 《植物研究》 北大核心 2026年第1期145-157,共13页
为揭示长白落叶松(Larix olgensis)无性系在水分利用特征上的遗传变异规律,并筛选出耐旱性优良的无性系,该研究以25个37年生长白落叶松优良无性系为对象,测定9项与耐旱相关的枝、叶性状并分析其相关性,采用隶属函数法和聚类分析法对无... 为揭示长白落叶松(Larix olgensis)无性系在水分利用特征上的遗传变异规律,并筛选出耐旱性优良的无性系,该研究以25个37年生长白落叶松优良无性系为对象,测定9项与耐旱相关的枝、叶性状并分析其相关性,采用隶属函数法和聚类分析法对无性系耐旱性进行综合评价。结果表明:长白落叶松针叶性状在无性系之间均存在极显著差异(P<0.01),其中解剖和形态性状变异系数较小(11.06%~11.83%),而生理性状变异系数较大(22.15%~39.24%);枝条性状在无性系之间均无显著差异,其中水力直径变异系数最小(6.15%),细胞壁加固指数变异系数最大(25.26%)。枝、叶性状在各自器官内均呈较强的相关性:叶片表皮厚度与皮层厚度呈显著正相关(P<0.05),且二者与水分利用效率均呈显著负相关(P<0.01;P<0.05);气孔蒸腾指数与残余蒸腾指数呈显著负相关(P<0.01),与比叶面积呈显著正相关(P<0.05)。枝性状水力直径、理论导水率与细胞壁加固指数呈显著负相关(P<0.01)。然而,器官间仅针叶气孔蒸腾指数与枝条细胞壁加固指数呈显著负相关(P<0.05)。主成分分析显示,9个枝、叶性状组成2个相对独立的性状轴,枝性状构成的轴1反映水力效率与安全的权衡;叶性状构成的轴2反映水分策略从保守型到高效型的权衡。基于综合耐旱性评价结果,可将25个长白落叶松无性系分为综合强耐旱型、中等耐旱型和不耐旱型3类,其中无性系338、774、128、125、214和565表现出较强的耐旱性。研究结果为不同类型干旱地区筛选适宜的优良耐旱无性系造林材料提供理论依据和实践参考。 展开更多
关键词 长白落叶松 无性系 水力性状 水分利用效率 隶属函数 耐旱性
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部