Advances in Trehalose Biosynthesis Pathways and Application of Molecular Biology Technique

This paper aims to provide better guidance for construction of trehalose-producing recombinant strains to further improve the yield of trehalose. The research progress on trehalose biosynthesis pathways and the application of molecular biology technique in trehalose study in recent 30 years, especially the last 10 years are reviewed. Results show that there are 5 pathways of trehalose synthesis. Although enzymes and genes of trehalose synthesis have been isolated and genetic engineering strains have increased gradually, the improvement of trehalose yield is still inadequate because most recombinant strains are limited to study the physicochemical properties of single enzyme. With the development of modern biological technology, especially the rapid development of DNA recombinant technology, metagenomics and synthetic biology, high expression of heterologous trehalose in recombinant strains would become a hot research topic in the future.

New developments in Biotechnology-an overview

人类运用生物技术已经几千年了。直到上个世纪,发酵方法生产啤酒、白酒、面包、酱油以及其它食品都是在农产品领域的主要应用。自从50年前DNA和RNA结构和作用被揭示以来,一场生物技术的革命便产生了,并导致了两项关键技术的发展:1）通过基因技术进行遣传因素的修改;2）新型快速多样分析工具;最新的发展都基于遗传学。这篇文章我将探讨以下问题:遗传因子修改的进展和公众认可的争论;基因学技术在农产品领域的应用;我的TNO研究所与中国伙伴联合的生物技术项目的例子;谷物科技方面的生物技术。

RNAi,a new therapeutic strategy against viral infection

RNA interference (RNAi) is an adaptive defense mechanism triggered by double-stranded RNA (dsRNA). It is a powerful reverse genetic tool that has been widely employed to silence gene expression in mammalian and human cells.RNAi-based gene therapies, especially in viral diseases have become more and more interesting and promising. Recently,small interfering RNA (siRNA) can be used to protect host from viral infection, inhibit the expression of viral antigen and accessory genes, control the transcription and replication of viral genome, hinder the assembly of viral particles, and display influences in virus-host interactions. In this review, we attempt to present recent progresses of this breakthrough technology in the above fields and summarize the possibilities of siRNA-based drugs.

Functional genomic approach to the study of biodiversitywithin Trichoderma

Trichoderma is a fungal genus of great and demonstrable biotechnological value, but its genome is poorly surveyed compared with other model microorganisms. Due to their ubiquity and rapid substrate colonization, Trichoderma species have been widely used as biocontrol organisms for agriculture, and their enzyme systems are widely used in industry. Therefore, there is a clear interest to explore beyond the phenotype to exploit the underlying genetic systems using functional genomics tools. The great diversity of species within the Trichoderma genus, the absence of optimized systems for its exploration, and the great variety of genes expressed under a wide range of ambient conditions are the main challenges to consider when starting a comprehensive functional genomics study. An initial project started by three Spanish groups has been extended into the project TRICHOEST, funded by the EU (FP5, QLRT-2001-02032) to target the transcriptome analysis of selected Trichoderma strains with biocontrol potential, in conditions related to antagonism, nutrient stress and plant interactions. Once specific conditions were defined, cDNA libraries were produced and used for EST sequencing. Nine strains from seven Trichoderma species have been considered in this study and an important amount of gene sequence data has been generated, analyzed and used to compare the gene expression in different strains. In parallel to sequencing, genomic expression studies were carried out by means of macro-arrays to identify genes expressed in specific conditions. In silico analysis of DNA sequencing data together with macro-array expression results have lead to a selection based on the potential use of the gene sequences. The selected clone sequences were completed and cloned in appropriate vectors to initiate functional analysis by means of expression studies in homologous and heterologous systems.

Sequences and Phylogeny Analysis of rbcL Gene in Marine Chlorophyta

The rbcL gene of Ulva pertusa,Enteromorpha prolifera and Monostroma grevillei was amplified,sequenced and analyzed.By comparing the rbcL sequences with seven other Ulvales species retrieved from GenBank,the sequence divergences and thephyletic evolution were analyzed and the phylogenetic tree was constructed.From the phylogenetic tree,it can be found that U.per-tusa,E.prolifera and U.californica group in one branch,while E.compressa,U.rigida and U.fenestrata cluster in another clade.Obviously,unlike the Enteomorpha species,the Ulva species do not gather in one branch.Therefore Ulva and Enteomorpha might beaffiliates of one genus.E.compressa and E.intestinalis gathered together,which coincided with the morphological characters.However,the thallus of U.pertusa is thick and with many holes,which is different from E.prolifera in morphology.They cluster togetherin the phylogenetic tree with a genetic distance of 0.005.The results indicate that Ulva and Enteromorpha are not distinguishedstrictly.

High-efficiency 18S microalgae barcoding by coalescent,distance and character-based approaches: a test in Chlorella and Scenedesmus

The relatively conserved 18S is often used in the phylogenetic analysis of microalgae. However, whether it can really help in barcoding microalgae needs to be evaluated. In this study the multiple approaches of coalescent, distance and character-based barcoding are first employed in C hlorella and Scenedesmus to test the efficiency of 18S sequences for barcoding green microalgae. We show that most Chlorella and Scenedesmus species, including the cryptic species, can be distinguished by 18S sequences with all coalescent General Mixed Yule-coalescent(GMYC), poisson tree process(PTP), and P ID, distance(ABGD) and character-based approaches. Both GMYC and PTP analyses produce more genetic groups. The P ID and ABGD analyses only cluster some species. All species(apart from a few of lineages) can be separated in character-based barcoding analysis with more than three character attributes. In comparison with previous barcoding results with r bcL, tufA, ITS and 16 S, 18S produces good resolution in identifying Chlorella and Scenedesmus. Our results reveal that 18S is highly efficient in identifying taxa of green microalgae at species level, based on a combination of multiple barcoding approaches. Combining 18S with other gene markers may be useful in barcoding microalgae.

Systems perspectives on mRNA processing

The application of genomic technologies to the study of mRNA processing is increasingly conducted in metazoan organisms in order to understand the complex events that occur during and after transcription. Large-scale systems analyses ofmRNA-protein interactions and mRNA dynamics have revealed specificity in mRNA transcription, splicing, transport, translation, and turnover, and have begun to make connections between the different layers ofmRNA processing. Here, we review global studies of post-transcriptional processes and discuss the challenges facing our understanding of mRNA regulation in metazoan organisms. In parallel, we examine genome-scale investigations that have expanded our knowledge of RNA-binding proteins and the networks of mRNAs that they regulate.

Characteristics of Antisense Non-coding RNA in the INK4 Locus and Its Roles in Disease

Abstract With the development of genome-wide sequencing technology, 195 types of functional long non-coding RNAs （lncRNAs） have so far been found, and their cellular roles are gradually being revealed. Now lncRNAs have become a hotspot in the life science. These small molecules exist in almost all higher eukaryotes, and have very important regulatory roles in these organisms. This review briefly summarizes recent progress in researches on antisense non-coding RNA in the INK4 locus.

Awareness and Perception of Genetic Modification among Science and Technical Vocational Teachers in Guyana： Focusing on Genetically Modified Foods

A study was conducted to determine the awareness and perception of biotechnology focusing on genetically modified foods among public secondary school science and technical vocational teachers in Guyana. A questionnaire was administered to 228 randomly selected teachers of 42 schools in six administrative regions of Guyana, representing about 90% of the population. The results revealed that there was a low level of awareness among the teachers： those who were knowledgeable about the subject were mainly Biology, Agricultural Science and Integrated Science teachers. Most teachers （almost 90%） indicated that the public is not receiving adequate information about genetically-modified foods and opined that the television should be the main medium to provide information. The study also revealed that teachers felt that ethical, religious and social issues should be considered when applying the technology. This view did not vary based on qualifications, years in the profession or subjects taught. Genetic modification was more acceptable to plant-based than animal-based foods, although they seemed ambivalent as to whether genetically modified foods can be harmful to their health. The implications of these findings are that more teachers in various subject areas should be informed about emerging issues in sciences to enable them to better analyze the subject matter, transfer information to the students, and form attitudes and opinions based on facts.

Synthetic aperture radar imaging based on attributed scatter model using sparse recovery techniques

The sparse recovery algorithms formulate synthetic aperture radar （SAR） imaging problem in terms of sparse representation （SR） of a small number of strong scatters＇ positions among a much large number of potential scatters＇ positions, and provide an effective approach to improve the SAR image resolution. Based on the attributed scatter center model, several experiments were performed with different practical considerations to evaluate the performance of five representative SR techniques, namely, sparse Bayesian learning （SBL）, fast Bayesian matching pursuit （FBMP）, smoothed 10 norm method （SL0）, sparse reconstruction by separable approximation （SpaRSA）, fast iterative shrinkage-thresholding algorithm （FISTA）, and the parameter settings in five SR algorithms were discussed. In different situations, the performances of these algorithms were also discussed. Through the comparison of MSE and failure rate in each algorithm simulation, FBMP and SpaRSA are found suitable for dealing with problems in the SAR imaging based on attributed scattering center model. Although the SBL is time-consuming, it always get better performance when related to failure rate and high SNR.

The Change-Over of Yin-yang and Gene Regulation in Kidney Deficiency Syndromes

The present paper studies gene regulation in kidney deficiency syndromes from the simple Nephrotic Syndrome and with the principle of positive-negative regulation to control the change-over ofyin-yang, the modem molecular biological techniques can be used, such as gene chip, representational difference analysis （RDA） and gene sequence analysis, so as to investigate the inner relationship between the genes and kidney deficiency syndromes and prove the effect given by these genes on the pathophysiological status of change-over ofyin-yang in kidney deficiency syndromes. This philosophical approach and method can also be adopted for studies of the related genes in other TCM syndromes.

Assessing protein-DNA interactions: Pros and cons of classic and emerging techniques

Investigation of protein-DNA interactions provides important information for understanding gene function and regulation, but identification and validation of specific interactions remain major challenges in the post-genomics era. Therefore, effective and economical methods to assess protein-DNA interactions are highly sought-after by molec- ular biologists.

Genomes and evolutionary genomics of animals

Alongside recent advances and booming applications of DNA sequencing technologies, a great number of complete genome sequences for animal species are available to researchers. Hundreds of animals have been involved in whole genome se- quencing, and at least 87 non-human animal species＇ complete or draft genome sequences have been published since 1998. Based on these technological advances and the subsequent accumulation of large quantity of genomic data, evolutionary genomics has become one of the most rapidly advancing disciplines in biology. Scientists now can perform a number of comparative and evolu- tionary genomic studies for animals, to identify conserved genes or other functional elements among species, genomic elements that confer animals their own specific characteristics and new phenotypes for adaptation. This review deals with the current ge- nomic and evolutionary research on non-human animals, and displays a comprehensive landscape of genomes and the evolution- ary genomics of non-human animals. It is very helpful to a better understanding of the biology and evolution of the myriad forms within the animal kingdom [Current Zoology 59 （1）： 87-98, 2013].