Immunogenicity of multiple-epitope antigen gene of HCV carried by novel biodegradable polymers     

Yuan Yang  Yu KuangYu Liu  Wanyi Li  Zhonghua JiangLiying Xiao  Mingyuan Li 《Comparative immunology, microbiology and infectious diseases》2011,34(1):65-72

In order to develop a promising vaccine candidate utilizing a combined approach to induce both antibody production and T-cell activity, the DNA fragment containing MA of HCV with five conserved epitopes was synthesized. Two types of HCV vaccine candidates (the DNA type and DNA/polymers) were constructed using MA. PLA-PEG-PLA and PLGA-PEG-PLGA were synthesized and used as micelles with encapsulated plasmid pcDNA3.1(+)-MA. The preparation of copolymers, the cloning and analysis of recombinant plasmid DNA, in vitro expression, and immunogenicity in transgenic mice were evaluated in detail. The results indicated that even single immunization and oral immunization with DNA/polymers achieved satisfying immune responses in vivo tests. As biodegradable and nontoxic triblock copolymers, the novel copolymers demonstrated a great advantage, as they made long-term and single-immunizing vaccines possible; in addition, the copolymers showed a better adjuvant effect and scarcely any side effects.  相似文献   

利用 HPLC 分析菠萝愈伤组织 DNA 甲基化水平     

林文秋  肖熙鸥  张红娜刘胜辉  孙伟生  李运合  吴青松 《热带作物学报》2018,39(11):2220-2224

建立菠萝 DNA 甲基化水平的 HPLC 测定方法，分析菠萝愈伤组织 DNA 甲基化水平变化，为进一步研究菠萝 体细胞无性系变异机理奠定基础。通过对流动相和水解温度等条件的优化，建立菠萝 DNA 甲基化水平的检测方法。结 果表明，分离 C 和 5m-C 的最佳流动相为甲醇∶磷酸二氢钾∶三乙胺为 10∶90∶0.2（V/V），pH 3.0，DNA 的最佳水解 温度为 90 ℃。利用此体系分析菠萝愈伤组织和胚性愈伤组织的 DNA 甲基化变化，结果表明，菠萝愈伤组织在分化过 程中 DNA 总甲基化水平呈动态变化，变化范围为 5.14%~96.86%。此外，胚性愈伤组织甲基化水平低于非胚性愈伤组 织。推测 DNA 甲基化影响菠萝愈伤组织的分化及胚性愈伤组织的形成。  相似文献   

利用基因组信息提高畜禽生产性能研究进展     

周喜荣  于丽娟  张玉华  玛尔孜亚·亚森  蒋晓梅  拉扎特·艾尼瓦尔  张艳花 《中国畜牧兽医》2020,47(1):156-163

为了满足人们对畜产品需求的快速增长，必须在加快畜禽产业发展的同时把对环境的影响降到最低，提高畜禽遗传特性有望促进这一问题的解决。进入21世纪以来，以基因组选择为核心的分子育种技术迎来了发展机遇，利用该技术可实现早期准确选择，从而大幅度缩短世代间隔，加快群体遗传进展，并显著降低育种成本。虽然在某些畜种中（如奶牛），基因组选择取得了成功，群体也获得较大遗传进展，但仍无法满足快速增长的需求。因此，亟需寻找能够进一步加快遗传进展的方法。研究表明，在SNP标记数据中加入目标性状的已知功能基因信息，可以提高基因组育种值预测的准确性，进而加快遗传进展。而挖掘更多基因组信息的同时，开发更优化的分析方法可以更有助于目标的实现。文章总结了主要畜禽物种的可用基因组数据，包括牛、绵羊、山羊、猪和鸡以及这些数据是如何有助于鉴定影响重要性状的遗传标记和基因，从而进一步提高基因组选择的准确性。  相似文献   

Soil biodiversity and DNA barcodes: opportunities and challenges     

《Soil biology & biochemistry》2015

Soils encompass a huge diversity of organisms which mostly remains to be characterized due to a number of methodological and logistical issues. Nonetheless, remarkable progress has been made in recent years toward developing strategies to characterize and describe soil biodiversity, especially thanks to the development of molecular approaches relying on direct DNA extraction from the soil matrix.Metabarcoding can be applied to DNA from any environment or organism, and is gaining increasing prominence in biodiversity studies. This approach is already commonly used to characterize soil microbial communities and its application is now being extended to other soil organisms, i.e. meso- and macro-fauna.These developments offer unprecedented scientific and operational opportunities in order to better understand soil biodiversity distribution and dynamics, and to propose tools and strategies for biodiversity diagnosis. However, these opportunities also come with challenges that the scientific community must face. Such challenges are related to i) clarification of terminology, (ii) standardisation of methods and further methodological development for additional taxonomic groups, (iii) development of a common database, and (iv) ways to avoid waste of information and data derived from metabarcoding. In order to facilitate common application of metabarcoding in soil biodiversity assessment, we discuss these opportunities and challenges and propose solutions towards a more homogeneous framework.  相似文献   

Selecting the hologenome to breed for an improved feed efficiency in pigs—A novel selection index     

Ramona Weishaar  Robin Wellmann  Amelia Camarinha-Silva  Markus Rodehutscord  Jörn Bennewitz 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(1):14-22

Most traits in animal breeding, including feed efficiency traits in pigs, are affected by many genes with small effect and have a moderately high heritability between 0.1 and 0.5, which enables efficient selection. Since the microbiota composition in the gastrointestinal tract is also partly heritable and was shown to have a substantial effect on feed efficiency, the host genes affect the phenotype not only directly by altering metabolic pathways, but also indirectly by changing the microbiota composition. The effect of the microbiota composition on the breeding value of an animal is the conditional expectation of its breeding value, given the vector with microbiota frequencies, that is The breeding value of an animal can therefore be decomposed into a heritable contribution that arises from an altered microbiota composition and a heritable contribution that arises from altered metabolic pathways within the animal, so Instead of selecting for breeding value , an index comprising the two components and with appropriate weights, that is , can be used. The present study shows how this breeding strategy can be applied in pig genomic selection breeding scheme for two feed efficiency traits and daily gain.  相似文献   

Immunotherapy in Veterinary Oncology     

Philip J. Bergman 《Veterinary Clinics of North America: Small Animal Practice》2014

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Characterization of Genomic Integration and Transgene Organization in Six Transgenic Rapeseed Events     

WU Yu-hua  ;ZHANG Li  ;WU Gang  ;NIE Shu-jing  ;LU Chang-ming 《中国农业科学(英文版)》2014,(9):1865-1876

To characterize the DNA rearrangement of both the T-DNA region and the genomic insertion site during T-DNA insertion, the Genomewalker strategy was used to isolate the junctions between the inserted DNA and the plant genomic DNA in six rapeseed events as well as the genomic DNA at the sites before integration. During transformation in each of the six events, portions of both the right border（RB） and left border（LB） regions of the T-DNA were deleted, ranging from a 7 nucleotide deletion of the LB repeats in event RF1 to a 207 bp deletion of the LB region in event RF2. For the six events, T-DNA integration resulted in a deletion at the target site spanning less than 100 bp. Sequence analysis indicated that the T-DNA was integrated into the coding region of various native rapeseed genes in events RF1 and RF2. Duplications of the genomic DNA target site were observed in events RF2, RF3 and Topas 19/2. And multimerization of transgenes was found in event Topas 19/2, in which, the T-DNA was integrated as a head-to-head（RB-to-RB） concatemer into the recipient genome. In event MS1, chromosomal translocation or a large target-site deletion may have occurred during T-DNA integration, which was identified due to a failure to amplify the presumptive insertion site based on the flanking rapeseed DNA sequences. Our results provide comprehensive data concerning transgene organization and the genomic context of the T-DNA in six rapeseed events, which can aid in the developing of insert fingerprinting and the monitoring of long-term genetic stability and potential unintended effects of transgenic events.  相似文献   

Controlling sprouting in potato tubers using ultraviolet-C irradiance     

《Postharvest Biology and Technology》2014

Legislation limiting the use of chlorpropham (CIPC), the major potato sprout suppressant, has led to a need for new technologies to extend storage life of tubers. Ultra violet C (UV-C) has been used postharvest to reduce disease incidence on many crops, yet its use and efficacy as a sprout suppressant has not been investigated. The aim of this project was to identify the optimum dose and treatment timing of UV-C treatment on potato tubers as an alternative method of sprout suppression to reduce the dependence on chemical sprout suppressants. Up to six potato cultivars over two seasons were treated with varying doses of UV-C ranging from 0 to 30 kJ m⁻² either at harvest or at first indication of dormancy break. The tubers were stored at 9 °C and sprout growth and incidence assessed. Treatment with moderate UV-C doses (5–20 kJ m⁻²) suppressed sprout length and sprout incidence in a range of cultivars. Periderm DNA damage and programmed cell death were not detected in response to any of the UV-C doses. The inactive ABA metabolite, ABA-GE, increased in response to 10 or 20 kJ m⁻² within 72 h of treatment. Multivariate analysis showed a negative relationship between ABA metabolites and sprout growth/incidence during storage. This study found that UV-C reduced sprout growth in potato with no deleterious effects on tuber quality. This suggests potential for further development as an alternative or supplement to conventional sprout suppressant technologies.  相似文献   

高含固率木质纤维素厌氧发酵物总DNA的4种提取方法比较     

马旭光  刘素君  江滔  常佳丽  唐琼 《中国沼气》2020,(2):28-35

不同的样本特性和提取方法对获得微生物总DNA的质量有重要影响。文章基于高含固率木质纤维素厌氧发酵物腐殖酸、酚类物质含量高、质地均一性差、微生物浓度低的特点,研究了4种方法提取不同高含固率粪秸厌氧发酵物中微生物总DNA的效果。结果表明,常规的十二烷基磺酸钠法(sodium dodecyl sulfate,SDS)、十二烷基磺酸钠和溴化十六烷基三甲铵结合法(sodium dodecyl sulfate and cetyltrimethyl ammonium bromide,SDS-CTAB)和商业的粪便试剂盒法提取的DNA质量均较差,SDS法和试剂盒法未能获得聚合酶链式反应(polymerase chain reaction,PCR)扩增目的条带,SDS-CTAB法得到的条带较模糊;改进SDS-CTAB法获得的DNA杂质少、纯度高,具有较好的稳定性,A260/A280和A260/A230值分别为1.74~1.86和1.65~1.86,每克样品的DNA浓度在50 ng·μL^-1以上,电泳条带单一齐整、清晰明亮,PCR扩增的目的条带清晰度高,适宜后续分子生物学技术的分析。林格氏液洗脱、聚乙烯吡咯烷酮-40(Polyvinyl Pyrrolidone-40,PVP-40)洗涤液除杂以及裂解液和多种酶联合破壁是改进SDS-CTAB法获得该类专一性样本高质量微生物总DNA的关键步骤。  相似文献   

Response of the soil fungal community to multi-factor environmental changes in a temperate forest     

《Applied soil ecology》2014

Both environmental and climatic changes are known to influence soil microbial biomes in terrestrial ecosystems. However, there are limited data defining the interactive effects of multi-factor environmental disturbances, including N-deposition, precipitation, and air temperature, on soil fungal communities in temperate forests. A 3-year outdoor pot experiment was conducted to examine the temporal shifts of soil fungal communities in a temperate forest following N-addition, precipitation and air temperature changes. The shifts in the structure and composition of soil fungal communities were characterized by denaturing gradient gel electrophoresis and DNA sequencing. N-addition regimen induced significant alterations in the composition of soil fungal communities, and this effect was different at both higher and lower altitudes. The response of the soil fungal community to N-addition was much stronger in precipitation-reduced soils compared to soils experiencing enhanced precipitation. The combined treatment of N-addition and reduced precipitation caused more pronounced changes in the lower altitude versus those in the higher one. Certain fungal species in the subphylum Pezizomycotina and Saccharomycotina distinctively responded to N fertilization and soil water control at both altitudes. Redundancy discrimination analysis showed that changes in environmental factors and soil physicochemical properties explained 43.7% of the total variability in the soil fungal community at this forest ecosystem. Variations in the soil fungal community were significantly related to the altitude, soil temperature, total soil N content (TN) and pH value (P < 0.05). We present evidence for the interactive effects of N-addition, water manipulation and air temperature to reshape soil fungal communities in the temperate forest. Our data could provide new insights into predicting the response of soil micro-ecosystem to climatic changes.  相似文献