粪产碱杆菌DN25基因组分析与功能挖掘

产碱杆菌属(Alcaligenes)是一类在环境污染修复领域应用较广泛的革兰氏染色阴性细菌。本研究以1株由课题组筛选获得的能降解氰化物、苯酚的粪产碱杆菌(A.faecalis)DN25为研究对象,通过全基因组测序分析,探讨该菌株的潜在功能。结果表明：DN25基因组大小为4 143 808 bp, GC占比为56.51%。通过COG、 GO和KEGG数据库对DN25基因组进行功能注释,共注释3 805个蛋白编码基因,发现DN25基因组以代谢功能基因为主,同时还拥有较多表达外界防御系统和自我调节系统的基因。通过与其他菌株基因组的比较,发现DN25与A.faecalis MUB14、A.faecalis P156、A.faecalis SCSIO.B001和A.faecalis ZD02都具有良好的共线性。本研究工作为后续深入开展产碱杆菌DN25生物催化功能研究提供了基因组信息和基因资源。     

基于简化基因组的花生InDel标记开发和功能解析

InDel在基因组中的分布密度仅次于SNP,可作为动植物群体遗传分析、分子辅助育种等研究领域的有效分子标记。花生是世界范围内重要的油料作物之一。目前,花生栽培种全基因组已经公布,为准确挖掘花生基因组信息提供了重要参考。本研究通过169份花生核心种质的GBS(Genotyping-by-sequencing)测序和比对,共获得大小分布在1～14 bp范围内的10401个InDels。染色体Arahy.16上分布的InDels最多,达741个;而在染色体Arahy.08上分布的最少,有263个。参考基因组注释信息,仅有1167个InDels分布在功能基因相关区域。经GO注释,InDel分子功能主要包括催化活性(catalytic activity)和结合(binding);生物过程主要涉及代谢过程(metabolic process)、单组织过程(single-organism process)和细胞过程(cellular process)。经KEGG通路分析发现,InDels所在的基因区域的功能主要与代谢相关。本研究开发出全基因组水平的InDel标记,并做了相应功能分类和注释,为进一步分子验证和利用提供丰富的基因资源。     

喜温嗜酸硫杆菌SM-1的ROS防护机制

【目的】从基因组水平探讨生物冶金微生物——喜温嗜酸硫杆菌(Acidithiobacillus caldus)的活性氧类物质(Reactive oxygen species,ROS)防护机制。【方法】采用罗氏454 GS FLX测序平台对喜温嗜酸硫杆菌SM-1进行全基因组测序,利用NCBI非冗余蛋白数据库、Uniport蛋白数据库对全基因组序列进行功能注释,并采用基因组百科全书数据库(KEGG)进行基因组代谢途径重构,通过比较基因组学方法分析SM-1基因组中参与ROS防护相关的基因及可能的分子机制。【结果】SM-1细胞内的酶促抗氧化系统可用于清除细胞内产生的ROS物质,而非酶促抗氧化系统可用于维持细胞内的还原性内环境;细胞内的DNA损伤修复系统可用于修复DNA的氧化损伤从而保持个体遗传物质的稳定性。此外,SM-1基因组中大量的转座元件可能会增加基因组的可塑性以适应极端冶金环境。【结论】SM-1基因组序列的获得为从整体水平揭示喜温嗜酸硫杆菌适应生物冶金环境ROS氧化损伤的防护机制提供了帮助,对于SM-1的ROS防护机制的认知也为进一步通过遗传改造、提升其在高浓度重金属离子冶金环境中的抗性、提高冶金效率提供了理论指导。     

桑氏链霉菌KJ40全基因组测序及分析

【背景】桑氏链霉菌(Streptomyces sampsonii)KJ40是一株具有防病、促生多重功能的放线菌,有作为生物农药的潜力。目前还没有相关研究报道S.sampsonii全基因组序列,这限制了其功能基因、代谢产物合成途径及比较基因组学等研究。【目的】解析S.sampsonii KJ40的基因组序列信息,以深入研究该菌株防病促生机制及挖掘次级代谢产物基因资源。【方法】利用Illumina HiSeq高通量测序平台对KJ40菌株进行全基因组测序,使用相关软件对测序数据进行基因组组装、基因预测和功能注释、预测次级代谢产物合成基因簇、共线性分析等。【结果】基因组最后得到9个Scaffolds和578个Contigs,总长度为7 261 502 bp,G+C%含量平均为73.41%,预测到6 605个基因、1 260个串联重复序列、804个小卫星序列、67个微卫星序列、90个tRNA、9个rRNA和19个sRNA。其中,2 429、3 765、2 890、6 063和1 911个基因分别能够在COG、GO、KEGG、NR和Swiss-Prot数据库提取到注释信息。同时,还预测得到21个次级代谢产物合成基因簇。基因组测序数据提交至NCBI获得Gen Bank登录号:LORI00000000。S.sampsonii KJ40与Streptomyces coelicolor A3(2)、Streptomyces griseus subsp.griseus NBRC 13350三株链霉菌基因组存在翻转、易位等基因组重排,3个基因组共有1 711个蛋白聚类簇。【结论】研究为从基因组层面上解析KJ40菌株具有良好促生防病效果的内在原因提供基础数据,为深入了解链霉菌次级代谢合成途径提供参考信息,对S.sampsonii后续相关研究具有重要意义。     

榆树叶片形成虫瘿过程中转录组学分析

榆瘿蚜取食侵染榆树叶片形成了榆树虫瘿,本研究采用新一代的高通量Illumina Hi Seq^TM 2000技术测序平台对榆瘿蚜取食刺激的榆树叶片进行转录组测序和功能注释,利用生物学方法对基因表达和功能进行研究。测序获得23.19 Gb碱基序列信息,通过对测序数据进行序列过滤、拼接和去冗余,共获得102 017个Unigenes,通过NR与BLAST等数据库比对,其中有37 899个(37.15%) Unigense被注释。利用KOG、GO、KEGG等数据库对榆树虫瘿叶片的Unigense进行比对,按功其能将匹配的Unigenes基因划分25大类;GO注释将信息归纳为基因的3大主类,57个亚类;以KEGG数据库为参考,将Unigene定位到110个不同的代谢通路,包括氧化应激防御、植物激素信号转导、碳水化合物以及次生物代谢等代谢相关的Unigenes通路。本研究通过二代高通量转录组测序技术研究榆瘿蚜侵染下榆树虫瘿的相关基因,为今后研究榆瘿蚜侵染榆树叶片形成虫瘿的分子机理提供了基础资料。     

基于网络药理学的杜仲-山茱萸配伍治疗糖尿病的作用机制

为探讨杜仲-山茱萸治疗糖尿病的作用机制。研究利用网络药理学的方法,首先通过中药系统药理学数据库筛选出杜仲和山茱萸的活性成分和相关靶点,再利用DisGeNET、DrugBank等数据库筛选出糖尿病的潜在靶点。以STRING数据库对活性靶点构建蛋白互作网络(PPI)分析,采用Cytoscape3.7.0软件绘制其“成分-靶点-通路”的相互作用网络,通过CludterProfiler对靶蛋白进行生物过程、细胞组分及分子功能分析;京都基因与基因组(KEGG)的代谢通路分析。实验结果筛选得到杜仲-山茱萸有效成分30个,其中槲皮素、山奈酚、β-谷甾醇等成分对PTGS2、DPP4、ADRB2、PPARG等相关靶点通过IL-17信号通路、钙信号通路、脂肪细胞脂解的调控等参与氮化合物代谢过程、血液循环、脂肪细胞分化和血压调节等过程。综上,杜仲-山茱萸配伍治疗糖尿病存在多成分和多重药理作用机制,为进一步研究其治疗糖尿病药理实验提供了参考,也为其他中药的相关研究提供借鉴和参考。     

栽培种西番莲基因组序列及比较基因组分析

栽培种西番莲是中国南方广泛种植的果树,但是其基因组信息尚不清楚,严重制约了西番莲分子遗传学研究。本研究利用高通量测序得到的14.1 Gb原始数据及165.7 Mb组装到Scaffold水平、代表栽培种西番莲基因组的序列进行生物信息学分析。结果表明,西番莲基因组中含有大量的简单序列重复(simple sequence repeats, SSR)。通过与木薯和桃树基因组比对,西番莲基因组有23 053个预测基因。利用NR、Swiss Port、KEGG、InterPro、Pfam和GO数据库,西番莲预测基因能比对到282个植物基因组上。利用GO数据对注释基因的功能进行归类,即Biological process、Cellular component和Molecular function,再细化为41个二级功能,大部分基因与碳水化合物、有机酸、脂等代谢途径相关。KEGG通路富集将基因功能分为5大类19个二级功能,众多基因与新陈代谢通路相关,其中最大一类是碳水化合物代谢相关基因。通过基因家族的聚类分析,栽培种西番莲12 767个基因可以聚类到9 868个基因家族中,平均每个家族包含有1.29个基因,同时有291个特有基因家族。在进化关系中,栽培种西番莲与毛果杨和蓖麻的亲缘关系较近。本研究为西番莲的基因功能研究和分子育种奠定基础。     

乳腺癌特异性拷贝数变异致DNA修复失衡

该研究通过整合4个功能诠释数据库(KEGG、GO、WIKI和PC)共发现56条DNA修复相关通路,确定了725个功能基因;并在筛查CCLE肿瘤细胞系和TCGA乳腺癌基因组数据的基础上,发现了89个乳腺癌特异性的拷贝数变异基因,其中包含了4个DNA修复相关的基因[BRCA1(breast cancer 1,early onset)、ERBB2(erb-b2 receptor tyrosine kinase 2)、G6PC(glucose-6-phosphatase,catalytic subunit)和PSME3(proteasome(prosome,macropain)activator subunit 3(PA28 gamma;Ki))]。进一步生物信息分析表明,乳腺癌基因组中17q21.31区域的拷贝数变异可通过改变BRCA1和PSME3基因的表达,从而影响DNA修复功能(如双链的断裂修复和DNA损伤相关检测点)。     

产甲烷常温古细菌和嗜热古细菌代谢网络拓扑结构与功能间的关联性研究

根据从KEGG数据库获得的产甲烷的常温古细菌Methanosarcina acetivorans(MAC)和嗜热古细菌Methanopyrus kandleri(MKA)的代谢网络,通过不同的网络属性特征的比较,发现常温古细菌MAC的代谢网络比嗜热古细菌MKA有更长的平均路径长度,更大的直径,这表明常温古细菌MAC的总体结构是相对低密度、松散的网络结构.同时为了从系统水平上分析这些特征蕴含的功能意义,采用了Grivan和Newman提出的模块算法(简称GN算法)分析这两个生物体的功能模块,并将所得的结果与KEGG数据库中的途径信息进行比较研究,发现大部分模块对应2~4个KEGG途径,表明这些网络模块均具有一定功能意义.     

白芷全基因组测序分析及BGLU基因家族分析

白芷为常用的药食同源物种,既是临床常用中药,又是香料,用途十分广泛。为获取白芷全基因组序列信息,该研究首次以杭白芷叶片DNA为材料,采用Nanopore测序技术构建杭白芷全基因组数据库,并利用生物信息学方法对获得的核苷酸序列进行组装、功能注释以及进化分析研究。结果表明：(1)原始测序数据过滤后获得662 Gb三代数据,Read N50约为32 932 bp,经过组装得到杭白芷基因组大小为5.6 Gb, Contig N50约为806 638 bp。(2)组装后的序列通过与KOG、GO、KEGG等功能数据库比对,得到了功能注释的基因占66.47%,KOG功能注释结果表明杭白芷的蛋白功能主要集中在一般功能预测、翻译后修饰、蛋白质转换、伴侣以及信号转导机制;GO功能分类表明杭白芷的基因集中在生物学过程及细胞组分;KEGG通路注释表明参与代谢途径的基因占主要地位。(3)杭白芷中鉴定到45个BGLU家族基因。该研究首次利用第三代测序技术对杭白芷全基因组进行解析,为杭白芷的系统生物学研究和BGLU在杭白芷生长发育中的后续功能研究提供了重要的理论参考。     

The KEGG databases at GenomeNet

The Kyoto Encyclopedia of Genes and Genomes (KEGG) is the primary database resource of the Japanese GenomeNet service (http://www.genome.ad.jp/) for understanding higher order functional meanings and utilities of the cell or the organism from its genome information. KEGG consists of the PATHWAY database for the computerized knowledge on molecular interaction networks such as pathways and complexes, the GENES database for the information about genes and proteins generated by genome sequencing projects, and the LIGAND database for the information about chemical compounds and chemical reactions that are relevant to cellular processes. In addition to these three main databases, limited amounts of experimental data for microarray gene expression profiles and yeast two-hybrid systems are stored in the EXPRESSION and BRITE databases, respectively. Furthermore, a new database, named SSDB, is available for exploring the universe of all protein coding genes in the complete genomes and for identifying functional links and ortholog groups. The data objects in the KEGG databases are all represented as graphs and various computational methods are developed to detect graph features that can be related to biological functions. For example, the correlated clusters are graph similarities which can be used to predict a set of genes coding for a pathway or a complex, as summarized in the ortholog group tables, and the cliques in the SSDB graph are used to annotate genes. The KEGG databases are updated daily and made freely available (http://www.genome.ad.jp/kegg/).     

KEGG: kyoto encyclopedia of genes and genomes

KEGG (Kyoto Encyclopedia of Genes and Genomes) is a knowledge base for systematic analysis of gene functions, linking genomic information with higher order functional information. The genomic information is stored in the GENES database, which is a collection of gene catalogs for all the completely sequenced genomes and some partial genomes with up-to-date annotation of gene functions. The higher order functional information is stored in the PATHWAY database, which contains graphical representations of cellular processes, such as metabolism, membrane transport, signal transduction and cell cycle. The PATHWAY database is supplemented by a set of ortholog group tables for the information about conserved subpathways (pathway motifs), which are often encoded by positionally coupled genes on the chromosome and which are especially useful in predicting gene functions. A third database in KEGG is LIGAND for the information about chemical compounds, enzyme molecules and enzymatic reactions. KEGG provides Java graphics tools for browsing genome maps, comparing two genome maps and manipulating expression maps, as well as computational tools for sequence comparison, graph comparison and path computation. The KEGG databases are daily updated and made freely available (http://www. genome.ad.jp/kegg/).     

KEGG: Kyoto Encyclopedia of Genes and Genomes.

Kyoto Encyclopedia of Genes and Genomes (KEGG) is a knowledge base for systematic analysis of gene functions in terms of the networks of genes and molecules. The major component of KEGG is the PATHWAY database that consists of graphical diagrams of biochemical pathways including most of the known metabolic pathways and some of the known regulatory pathways. The pathway information is also represented by the ortholog group tables summarizing orthologous and paralogous gene groups among different organisms. KEGG maintains the GENES database for the gene catalogs of all organisms with complete genomes and selected organisms with partial genomes, which are continuously re-annotated, as well as the LIGAND database for chemical compounds and enzymes. Each gene catalog is associated with the graphical genome map for chromosomal locations that is represented by Java applet. In addition to the data collection efforts, KEGG develops and provides various computational tools, such as for reconstructing biochemical pathways from the complete genome sequence and for predicting gene regulatory networks from the gene expression profiles. The KEGG databases are daily updated and made freely available (http://www.genome.ad.jp/kegg/).     

Automated interpretation of metabolic capacity from genome and metagenome sequences

The KEGG pathway maps are widely used as a reference data set for inferring high-level functions of the organism or the ecosystem from its genome or metagenome sequence data. The KEGG modules, which are tighter functional units often corresponding to subpathways in the KEGG pathway maps, are designed for better automation of genome interpretation. Each KEGG module is represented by a simple Boolean expression of KEGG Orthology (KO) identifiers (K numbers), enabling automatic evaluation of the completeness of genes in the genome. Here we focus on metabolic functions and introduce reaction modules for improving annotation and signature modules for inferring metabolic capacity. We also describe how genome annotation is performed in KEGG using the manually created KO database and the computationally generated SSDB database. The resulting KEGG GENES database with KO (K number) annotation is a reference sequence database to be compared for automated annotation and interpretation of newly determined genomes.     

KEGG Mapper for inferring cellular functions from protein sequences

KEGG is a reference knowledge base for biological interpretation of large‐scale molecular datasets, such as genome and metagenome sequences. It accumulates experimental knowledge about high‐level functions of the cell and the organism represented in terms of KEGG molecular networks, including KEGG pathway maps, BRITE hierarchies, and KEGG modules. By the process called KEGG mapping, a set of protein coding genes in the genome, for example, can be converted to KEGG molecular networks enabling interpretation of cellular functions and other high‐level features. Here we report a new version of KEGG Mapper, a suite of KEGG mapping tools available at the KEGG website ( https://www.kegg.jp/ or https://www.genome.jp/kegg/ ), together with the KOALA family tools for automatic assignment of KO (KEGG Orthology) identifiers used in the mapping.     

Validation of metabolic pathway databases based on chemical substructure search

Metabolic pathway databases such as KEGG contain information on thousands of biochemical reactions drawn from the biomedical literature. Ensuring consistency of such large metabolic pathways is essential to their proper use. In this paper, we present a new method to determine consistency of an important class of biochemical reactions. Our method exploits the knowledge of the atomic rearrangement pattern in biochemical reactions, to reduce the automatic atom mapping problem to a series of chemical substructure searches between the substrate and the product of a biochemical reaction. As an illustrative application, we describe the exhaustive validation of a substantial portion from the latest release of the KEGG LIGAND database.     

Cold-induced activation of brown adipose tissue and adipose angiogenesis in mice

Exposure of humans and rodents to cold activates thermogenic activity in brown adipose tissue (BAT). This protocol describes a mouse model to study the activation of BAT and angiogenesis in adipose tissues by cold acclimation. After a 1-week exposure to 4 °C, adult C57BL/6 mice show an obvious transition from subcutaneous white adipose tissue (WAT) into brown-like adipose tissue (BRITE). The BRITE phenotype persists after continuous cold exposure, and by the end of week 5 BRITE contains a high number of uncoupling protein-1-positive mitochondria, a characteristic feature of BAT. During the transition from WAT into BRITE, the vascular density is markedly increased owing to the activation of angiogenesis. In BAT, cold exposure stimulates thermogenesis by increasing the mitochondrial content and metabolic rate. BAT and the increased metabolic rate result in a lean phenotype. This protocol provides an outstanding opportunity to study the molecular mechanisms that control adipose mass.     

Intrinsic differences in BRITE adipogenesis of primary adipocytes from two different mouse strains

BRITE (brown-in-white) cells are brown adipocyte-like cells found in white adipose tissue (WAT) of rodents and/or humans. The recruitment of BRITE adipocytes, referred to as the browning of WAT, is hallmarked by the expression of UCP1 and exerts beneficial metabolic effects. Here we address whether beyond systemic cues depot- and strain-specific variation in BRITE recruitment is determined by a cellular program intrinsic to progenitors. Therefore we compared the browning capacity of serum and investigated brown and BRITE adipogenesis in primary cultures of stromal-vascular cells isolated from interscapular brown adipose tissue (iBAT), inguinal white adipose tissue (iWAT) and epididymal white adipose tissue (eWAT) in two inbred mouse strains C57BL/6J (B6, a strain with low browning propensity) and 129/S6SvEv (129, a strain with high browning propensity). Paradoxically, serum collected from B6 mice was more potent in the promotion of browning than serum collected from 129 mice. Nevertheless, we demonstrate that depot- and strain-specific differences observed in vivo are pheno-copied in primary cultures in vitro, as judged by UCP1 expression and by functional analysis. Notably, primary adipocytes from 129 mice had a higher capacity for isoproterenol-induced uncoupled respiration than B6. We conclude that cues intrinsic to the progenitor cells contribute to differential BRITE adipogenesis. Further analyses demonstrate that these cues are independent of autocrine/paracrine mechanisms, BRITE progenitor abundance and genetic variation in the gene regulatory region of Ucp1 but rather depend on trans-acting factors. These results provide new insights on the molecular basis of strain and depot-specific differences in BRITE adipogenesis.     

Testing the performance of automated annotation of ESTs with the Kegg Orthology (KO) database demonstrates lack of completeness of clusters

The KEGG Orthology (KO) database was tested as a source for automated annotation of expressed sequence tags (ESTs). We used a control experiment where every EST was assigned to its cognate protein, and an annotation experiment where the ESTs were annotated by proteins from other organisms. Analyzing the results, we could assign classes to the annotation: correct, changed and speculated. The correct annotation ranged from 57 (Caenorhabditis elegans) to 81% (Homo sapiens). In spite of the changed annotation being low (1 in H. sapiens to 9% in Arabidopsis thaliana), the speculation was very high (18 in H. sapiens to 38% in C. elegans). We propose eliminating part of the speculated annotation using the KEGG Genes database to enrich KO clusters, decreasing the speculation from 38 to 2% in C. elegans. Thus, the KO database still demands some effort for moving sequences from Kegg GENES to KO, to complement the annotation performance.