遗传改造细菌基因组的策略:基因定点突变、基因失活和基因过表达（英文）

该综述较为全面地概述了当前针对大肠杆菌和谷氨酸棒杆菌基因组遗传改造的各个方法的具体流程、应用范围、注意事项以及其新颖之处,比较了针对基因定点突变、基因失活和基因过表达的各个方法所存在的优缺点,同时简单地介绍了利用质粒介导基因过表达所存在的问题。此外,还介绍了四种引物设计软件,并简单分析了它们的应用范围。为拟计划开展分子生物学实验的新手对关于细菌基因组遗传改造方法做了可靠的介绍,同时也为已进行相关实验的实验员提供关于基因定点突变、基因失活和基因过表达的最新信息。     

策略和表达：群文阅读教学的核心

提升学生的语文核心素养是语文教学的主要目标。提升学生的语文核心素养,离不开阅读策略的指导和表达能力的训练。群文阅读教学应以策略和表达为双翼,直接指向学生阅读素养和表达能力的提高。在群文阅读教学中,教师应因文而异、因材施教,策略、表达或同时并进,或交替进行,目的是促进学生的发展。     

生物遗传教学不再纸上谈兵——《遗传的物质基础：染色体、DNA和基因》教学设计

本节课的教学设计紧扣我国生物课程改革所重新确立的生物学课程标准和课程理念：面向全体学生,提高生物科学素养,倡导自主学习、探究学习、合作学习。用新的理念、新的思想指导教学实践,探索生物学学科教学与信息技术整合的教学方式。借助网络、多媒体技术优化教学过程,扩大信息量,充分激活学生的思维,引导学生自主地学、主动地学、     

“生殖、发育、遗传和变异“专题的复习策略

1生殖和发育的复习策略--突出知识之间的比较与辨析　　1.1无性生殖　　①类型:分裂生殖、出芽生殖、孢子生殖、营养生殖.　　②特点:子代保持母体的一切性状,因为新个体遗传物质与母体相同.　　③应用:扦插,嫁接、组织培养.　　组织培养过程:组织块(→脱分化)愈伤组织(→再分化)组织器官→完整植株.　　理论基础:细胞的全能性.　　培养基:必须含有植物生长发育所需要的全部营养物质.一般由五大类物质组成:无机盐(必须含有一定量的大量元素和微量元素)、碳源(如蔗糖等)、维生素(如维生素C、维生素B1等)、生长调节物质(如吲哚乙酸、萘乙酸、2,4-D等)、氮源(主要是氨基酸等)和水.……     

创造性表达教学的意义、着力点和实践策略

创造性表达是义务教育语文“新课标”强调的内容,进行创造性表达教学是语文教学的应有之义。创造性表达教学对学生想象能力的发展、创造性思维水平的提高、个性化的发展等都具有重要的意义。促进学生的创造性表达,可以从激发学生创造性表达的动机、丰富学生创造性表达的知识储备、培养学生创造性思维技能上着力。在实践中,教师需要将创造性表达纳入作文教学目标,依托语文教材展开创意练习和习作,创设基于情境的表达活动,并制定创造性表达的具体评价标准。     

赤眼鳟Myf5基因的克隆、序列和表达分析

生肌调节因子（MRF）基因家族的表达决定着肌细胞的命运,并控制其增殖和分化．Myf5是生肌调节因子MRF基因家族中的一个成员．本文提取赤眼鳟肌肉总RNA,采用RT—PCR技术获得赤眼鳟Myf5基因的部分cDNA序列,共338bp,编码112个氨基酸,含有部分bHLH结构．通过同源性分析发现赤眼鳟Myf5基因编码区与草鱼的同源性高达97．34％．半定量RT—PCR分析表明赤眼鳟Myf5基因在心脏和肾脏中表达量较高,鳃和肌肉中表达量次之,肝脏、脑和肠中表达量较弱．本结果为进一步研究该基因对肌肉生长发育的作用机理奠定了基础．     

聆听、回望和反思：关注孩子的情感表达

聆听 今天爸爸接我 三年的幼师学习生涯快结束时．我被分在省城一所一类幼儿园实习。通过一周的相处,孩子们与我差不多都熟识了。那天放学的时候,还没被接走的孩子有看图书的,有做游戏的,有的干脆眨巴着眼四处张望。主班老师在和一位家长交谈,而我在活动区整理东西。     

Microcalorimetry studies on the antibacterial effect of crude monkshood polysaccharide

In this paper, crude monkshood polysaccharide was isolated from Radix Aconiti Lateralis Preparata. The effects of crude monkshood polysaccharide on Escherichia coli and Staphylococcus aureus were investigated by microcalorimetry. The power-time curves of the bacterial growth at various concentrations (c) of crude monkshood polysaccharide were plotted with a TAM air isothermal microcalorimeter at 37 °C. The growth rate constant (μ), inhibitory ratio (I), peak-height (P _m), and peak-time (t _m) were calculated. From the data, the relationship between μ and c also was established. The growth rate constant μ decreased with the increasing concentrations of crude monkshood polysaccharide. Moreover, P _m reduced and t _m increased with increasing concentrations. The experimental results revealed that crude monkshood polysaccharide had inhibitory activity towards S. aureus and E. coli. Results obtained from our study strongly suggest that microcalorimetry is a fast, simple, and more sensitive technology that can be easily performed to study the effect of drugs on bacteria.     

Microcalorimetry studies of the antimicrobial actions of Aconitum alkaloids

The metabolic activity of organisms can be measured by recording the heat output using microcalorimetry. In this paper, the total alkaloids in the traditional Chinese medicine Radix Aconiti Lateralis were extracted and applied to Escherichia coli and Staphylococcus aureus. The effect of alkaloids on bacteria growth was studied by microcalorimetry. The power-time curves were plotted with a thermal activity monitor (TAM) air isothermal microcalorimeter and parameters such as growth rate constant (μ), peak-time (T_m), inhibitory ratio (I), and enhancement ratio (E) were calculated. The relationships between the concentration of Aconitum alkaloids and μ of E. coli or S. aureus were discussed. The results showed that Aconitum alkaloids had little effect on E. coli and had a potentially inhibitory effect on the growth of S. aureus.     

Improvement of a gene targeting system for genetic manipulation in Penicillium digitatumQian XU,Cong-yi ZHU,Ming-shang WANG,Xue-peng SUN,Hong-ye LI简

Penicillium digitatum is the most important pathogen of postharvest citrus. Gene targeting can be done in P. digitatum using homologous recombination via Agrobacterium tumefaciens mediated transformation (ATMT), but the frequencies are often very low. In the present study, we replaced the Ku80 homolog (a gene of the non-homologous end-joining (NHEJ) pathway) with the hygromycin resistance cassette (hph) by ATMT. No significant change in vegetative growth, conidiation, or pathogenicity was observed in Ku80-deficient strain (ΔPdKu80) of P. digitatum. However, using ΔPdKu80 as a targeting strain, the gene-targeting frequencies for both genes PdbrlA and PdmpkA were significantly increased. These results suggest that Ku80 plays an important role in homologous integration and the created ΔPdKu80 strain would be a good candidate for rapid gene function analysis in P. digitatum.     

Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants

The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation. However, the effects of Alternaria toxins on insects have just begun to be investigated. Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study. At a concentration of 50.0 μg/ml, the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P≥0.079), and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P≤0.001). However, this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml (P≥0.096). Therefore, the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids, demonstrating that the resistance mechanism triggered by the Alternaria toxin in the rose plant may also be used by the plant to defend itself against insects. Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants. The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P≤0.014). This result showed that the toxin-induced resistance related to the volatile changes of host plants.     

Family-based association study of ZNF533, DOCK4 and IMMP2L gene polymorphisms linked to autism in a northeastern Chinese Han population简

Objective

A study in a Caucasian population has identified two single-nucleotide polymorphisms (SNPs) in ZNF533, one in DOCK4, and two in IMMP2L, which were all significantly associated with autism. They are located in AUTS1 and AUTS5, which have been identified as autism susceptibility loci in several genome-wide screens. The present study aimed to investigate whether ZNF533, DOCK4, and IMMP2L genes are also associated with autism in a northeastern Chinese Han population.

Methods

We performed a similar association study using families with three individuals (one autistic child and two unaffected parents). A family-based transmission disequilibrium test (TDT) was used to analyze the results.

Results

There were significant associations between autism and the two SNPs of ZNF533 gene (rs11885327: χ ²=4.5200, P=0.0335; rs1964081: χ ²=4.2610, P=0.0390) and the SNP of DOCK4 gene (rs2217262: χ ²=5.3430, P=0.0208).

Conclusions

Our data suggest that ZNF533 and DOCK4 genes are linked to a predisposition to autism in the northeastern Chinese Han population.     

Inhibitory activities of microalgal extracts against Epstein-Barr virus DNA release from lymphoblastoid cells

This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus, Synechococcus elongatus, and Spirulina platensis against Epstein-Barr virus (EBV) in three Burkitt's lymphoma (BL) cell lines, namely Akata, B95-8, and P3HR-1. The antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction (PCR) technique. The methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in reducing cell-free EBV DNA (EC(50)<0.01 μg/ml) with a high therapeutic index (>28000). After fractionation by column chromatography, the fraction from Synechococcus elongatus (SEF1) reduced the cell-free EBV DNA most effectively (EC(50)=2.9 μg/ml, therapeutic index>69). Upon further fractionation by high performance liquid chromatography (HPLC), the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA (EC(50)=1.38 μg/ml, therapeutic index>14.5). This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.