Infection Dynamics of ATG8 in Leishmania: Balancing Autophagy for Therapeutics

In many regions of the world, Leishmaniasis is a cause of substantial mortality and ailment. Due to impediment in available treatment, development of novel and effective treatments is indispensable. Significance of autophagy has been accentuated in infectious disease as well as in Leishmaniasis, and it is having capability to be manifested as a therapeutic target. By evincing autophagy as a novel therapeutic regime, this study emphasized on the critical role of ATG4.1-ATG8 and ATG5-ATG12 complexes in Leishmania species. The objective here was to identify ATG8 as a potential therapeutic target in Leishmania. R71T, P56E, R18P are the significant mutations which shows detrimental effect on ATG8 while Arg276, Arg73, Cys75 of ATG4.1 and Val88, Pro89, Glu116, Asn117, and Gly120 are interacting residues of ATG8. Along with this, we also bring into spotlight an enticing role of Thiabendazole derivatives that interferes with the survival mechanisms by targeting ATG8. Further, the study claims that thiabendazole can be a potential drug candidate to target autophagy process in the infectious disease Leishmaniasis.     

石珊瑚演化的18S rDNA分子生物学和形态学研究

用分子生物学方法测定石珊瑚目一些现代种类的18S rDNA,构建石珊瑚的系统发生树,并且对石珊瑚目中一些亚目和科属的演化关系进行分子生物学和传统的比较形态学的对照研究,以期为石珊瑚起源和演化提供新的证据。研究表明： 1） 石珊瑚的早期演化至少有两个主要演化分支,这支持以前的形态分类研究和分子生物学研究的结果。尽管这两方面研究所得出的分支不尽相同,但都说明石珊瑚目的亚目一级有强烈分化; 2） 石珊瑚目的5个亚目不全是单系发生的,对Wells的传统分类提出了质疑。此项分子生物研究虽与大部分种的属和科级根据形态生物学的归属相符合,但还有些科的归属还有分歧,如Faviina亚目中的Rhizangiidae科和Faviina亚目中的Dendrophylliidae科等。     

Reappraisal of phylogenetic status and genetic diversity analysis of Asian population of Lentinula edodes

Phylogenetic relationship within the Lentinula genus is constructed based on the sequenced ITS fragments of the 60 Chinese wild L. edodes isolates and the sequence data of 48 isolates of different species from other districts downloaded from the GenBank. The 108 isolates of Lentinula genus are divided into two branches and seven groups, one branch and two groups in the New World, and the other branch and five groups in the Old World, and the isolates clustering of different groups corresponds obviously with the classification of the morphological species. Asian isolates are partitioned in group Ⅰ and Ⅴ, two of the five groups of the Old World, by which the germplasm resources status represented is of great importance shown by the phylogenetic analysis. Group Ⅴ which fills up the blank of geographic distribution has become one of the mainstream groups with an increased isolate number, while group Ⅰ has a tendency to dissimilate into two subgroups (Ia and Ib) with a huge isolate quantity and a coverage of most tested districts, suggesting that China (or Asia) is an important genetic diversity center of the natural population of Lentinula genus. Genetic analysis of Asian isolates based on groups Ia, Ib and group Ⅴ indicates that the diversity of the east coastal-land, northwestern highland and southwestern China and Himalayas districts is the most plentiful, which is the three priorities in diversity protection of Asian Lentinula population.     

A complete sequence and comparative analysis of a SARS-associated virus （Isolate BJO1）

The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-assoclated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs.We report the complete genome sequence and comparative analysis of an isolate (B J01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 20RFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS-associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to be involved in the immunoreactions between the virus and its host.Two amino acid changes have been detected in the M protein,which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides no evidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of other possible SARS-related pathogen(s).     

一株聚丙烯酰胺降解菌的分离鉴定及其生物降解

应用厌氧Hungate技术,从大庆油田常规污水回注工艺采油的采出液中分离到一株聚丙烯酰胺降解菌株A9。对该菌株进行形态、生理生化、分子生物学鉴定结果表明:菌株为革兰氏阳性(G ),短杆状,具有硫酸盐还原功能,产H2S,兼性厌氧,通过核糖体16S rDNA基因序列鉴定,菌株与Anaerofilum pentosovorans(AP716816S)的相似性为98%,暂时命名为Anaerofilum pen-tosovoransA9。扫描电镜和红外光谱分析结果表明:菌株以聚丙烯酰胺为唯一碳源,菌株作用前后表面结构发生变化,分子链上的酰胺基水解成羧基,侧链降解,部分官能团发生改变,浓度为500mg/L时,20 d菌株生物降解率为61.2%,其溶液粘度下降显著。气质联机(GC-MS)初步分析表明:聚合物发生断链生成的低分子量化合物除含双键、环氧和羰基的聚丙烯酰胺碎片外,大多属于一般丙烯酰胺低聚体的衍生物。     

Molecular phylogeny of coronaviruses including human SARS-CoV

The outbreak of SARS sets an urgent task to reveal the origin of human SARS-CoV, i.e. its relation to other known species of coronavirus, and to trace the genetic variation in the spreading process of SARS. Partial answer to the problem may be obtained from phylogenetic analy-sis of available genomes. We call a phylogenetic tree of different species of coronavirus including the human SARS-Cov a CoV Tree and that of different isolates of SARS-CoV a SARS Tree. CoV trees have been c…     

标本组学——树木学研究的新方法

树木学是一门不断发展、高度综合的学科。系统发生是树木学的基础,研究材料和序列数据一直是限制系统发生重建的重要因素。新技术的发展和应用通过拓展材料利用、改进和提升系统发生树的分辨率而将树木学的研究推向新的高度。标本馆不仅是树木物种凭证标本的保存地,保存了物种的形态、地理分布、生态、物候等信息,而且是重要的材料库。标本材料因制作和保存过程中高温和氧化导致基因组DNA降解和破碎化,一代测序技术由于技术限制而无法充分利用馆藏标本开展生命之树重建研究。新兴的标本组学是近年来基于二代测序技术发展起来的获取标本材料中基因组DNA的技术,这种技术通过对短片段测序和生物信息学方法拼接获得基因组DNA序列,因此可以充分利用馆藏标本材料,结合浅层测序和靶序列捕获能获得包括nrITS、叶绿体基因组、线粒体基因组以及单拷贝核基因等序列,从而满足系统发生重建的需要,且有着经济、省时、高效、准确的优势。新兴标本组学的应用将加速生命之树重建、DNA条形码、物种保护和资源可持续利用等方面的研究。