Marker Database Research Articles

Genome-wide development of transposable elements-based markers in foxtail millet and construction of an integrated database.

Transposable elements (TEs) are major components of plant genome and are reported to play significant roles in functional genome diversity and phenotypic variations. Several TEs are highly polymorphic for insert location in the genome and this facilitates development of TE-based markers for various genotyping purposes. Considering this, a genome-wide analysis was performed in the model plant foxtail millet. A total of 30,706 TEs were identified and classified as DNA transposons (24,386), full-length Copia type (1,038), partial or solo Copia type (10,118), full-length Gypsy type (1,570), partial or solo Gypsy type (23,293) and Long- and Short-Interspersed Nuclear Elements (3,659 and 53, respectively). Further, 20,278 TE-based markers were developed, namely Retrotransposon-Based Insertion Polymorphisms (4,801, ∼24%), Inter-Retrotransposon Amplified Polymorphisms (3,239, ∼16%), Repeat Junction Markers (4,451, ∼22%), Repeat Junction-Junction Markers (329, ∼2%), Insertion-Site-Based Polymorphisms (7,401, ∼36%) and Retrotransposon-Microsatellite Amplified Polymorphisms (57, 0.2%). A total of 134 Repeat Junction Markers were screened in 96 accessions of Setaria italica and 3 wild Setaria accessions of which 30 showed polymorphism. Moreover, an open access database for these developed resources was constructed (Foxtail millet Transposable Elements-based Marker Database; http://59.163.192.83/ltrdb/index.html). Taken together, this study would serve as a valuable resource for large-scale genotyping applications in foxtail millet and related grass species.

Molecular marker databases.

The detection and analysis of genetic variation plays an important role in plant breeding and this role is increasing with the continued development of genome sequencing technologies. Molecular genetic markers are important tools to characterize genetic variation and assist with genomic breeding. Processing and storing the growing abundance of molecular marker data being produced requires the development of specific bioinformatics tools and advanced databases. Molecular marker databases range from species specific through to organism wide and often host a variety of additional related genetic, genomic, or phenotypic information. In this chapter, we will present some of the features of plant molecular genetic marker databases, highlight the various types of marker resources, and predict the potential future direction of crop marker databases.

Fast and sensitive alignment of microbial whole genome sequencing reads to large sequence datasets on a desktop PC: application to metagenomic datasets and pathogen identification.

Next generation sequencing (NGS) of metagenomic samples is becoming a standard approach to detect individual species or pathogenic strains of microorganisms. Computer programs used in the NGS community have to balance between speed and sensitivity and as a result, species or strain level identification is often inaccurate and low abundance pathogens can sometimes be missed. We have developed Taxoner, an open source, taxon assignment pipeline that includes a fast aligner (e.g. Bowtie2) and a comprehensive DNA sequence database. We tested the program on simulated datasets as well as experimental data from Illumina, IonTorrent, and Roche 454 sequencing platforms. We found that Taxoner performs as well as, and often better than BLAST, but requires two orders of magnitude less running time meaning that it can be run on desktop or laptop computers. Taxoner is slower than the approaches that use small marker databases but is more sensitive due the comprehensive reference database. In addition, it can be easily tuned to specific applications using small tailored databases. When applied to metagenomic datasets, Taxoner can provide a functional summary of the genes mapped and can provide strain level identification. Taxoner is written in C for Linux operating systems. The code and documentation are available for research applications at http://code.google.com/p/taxoner.

SMDB: SOYBEAN MARKER DATABASE

Soybean Marker Database (SMDB) is a repository of important genomic information for soybean. At present several genomic databases are available for plants. Some of the important oilseeds plant databases are ATPID database, Castor Bean Genome Database, CGPDB, SoyBase, Legume Information System (LIS), Brassica database, Sinbase, etc. To gain comprehensive information from varied amount of resources, we developed this database which provides general as well as specific information at universal level. Along with this it also furnishes gene level information for various functional categories such as transcription factor, disease resistant varieties, heat shock protein, genetically modified strain of soybean. The bunch of information available to researchers today increases in tremendous manner. Hence understanding the plant genome specific databases for acquiring specific information is the demand of time for crop improvement and research programmes. SMDB is designed for the purpose of exploring potential gene differences in different plant genotypes, including genetically modified and disease resistant crops beneficial to the farmer who cultivate this crop. SMDB is publicly accessible for academic and research purpose at: http://www.bioinfoindia.org/smdb/ .

Next-generation transcriptome characterization in three Nacella species (Patellogastropoda: Nacellidae) from South America and Antarctica

The southern tip of South America and Antarctica are particularly interesting due to many genera and also species currently sharing between both areas. The genus Nacella (Patellogastropoda: Nacellidae) is distributed in different regions of South America and Antarctica living preferentially on rocks and boulders and grazing on algae, diatoms and bacterial films. We described the transcriptomes of three Nacella species, Nacella concinna (Strebel, 1908), inhabiting the Antarctic Peninsula; Nacella magallanica (Gmelin, 1791), from Patagonia and Nacella clypeater (Lesson, 1831), from central Chile. In total, we obtained over 20,000 contigs with an average length of 583bp. Homologous protein coding genes (PCGs) for mitochondrial genome of the three species were characterized and a database of molecular markers was also generated. This study represents the first publicly available report on pyrosequencing data for patellogastropod species, and provides an important comparative resource for studies in ecophysiology and evolutionary adaptation in marine invertebrate species.

Exploration of presence/absence variation and corresponding polymorphic markers in soybean genome.

This study was designed to reveal the genome-wide distribution of presence/absence variation (PAV) and to establish a database of polymorphic PAV markers in soybean. The 33 soybean whole-genome sequences were compared to each other with that of Williams 82 as a reference genome. A total of 33,127 PAVs were detected and 28,912 PAV markers with their primer sequences were designed as the database NJAUSoyPAV_1.0. The PAVs scattered on whole genome while only 518 (1.8%) overlapped with simple sequence repeats (SSRs) in BARCSOYSSR_1.0 database. In a random sample of 800 PAVs, 713 (89.13%) showed polymorphism among the 12 differential genotypes. Using 126 PAVs and 108 SSRs to test a Chinese soybean germplasm collection composed of 828 Glycine soja Sieb. et Zucc. and Glycine max (L.) Merr. accessions, the per locus allele number and its variation appeared less in PAVs than in SSRs. The distinctness among alleles/bands of PCR (polymerase chain reaction) products showed better in PAVs than in SSRs, potential in accurate marker-assisted allele selection. The association mapping results showed SSR + PAV was more powerful than any single marker systems. The NJAUSoyPAV_1.0 database has enriched the source of PCR markers, and may fit the materials with a range of per locus allele numbers, if jointly used with SSR markers.

OrthoMaM v8: a database of orthologous exons and coding sequences for comparative genomics in mammals.

Comparative genomic studies extensively rely on alignments of orthologous sequences. Yet, selecting, gathering, and aligning orthologous exons and protein-coding sequences (CDS) that are relevant for a given evolutionary analysis can be a difficult and time-consuming task. In this context, we developed OrthoMaM, a database of ORTHOlogous MAmmalian Markers describing the evolutionary dynamics of orthologous genes in mammalian genomes using a phylogenetic framework. Since its first release in 2007, OrthoMaM has regularly evolved, not only to include newly available genomes but also to incorporate up-to-date software in its analytic pipeline. This eighth release integrates the 40 complete mammalian genomes available in Ensembl v73 and provides alignments, phylogenies, evolutionary descriptor information, and functional annotations for 13,404 single-copy orthologous CDS and 6,953 long exons. The graphical interface allows to easily explore OrthoMaM to identify markers with specific characteristics (e.g., taxa availability, alignment size, %G+C, evolutionary rate, chromosome location). It hence provides an efficient solution to sample preprocessed markers adapted to user-specific needs. OrthoMaM has proven to be a valuable resource for researchers interested in mammalian phylogenomics, evolutionary genomics, and has served as a source of benchmark empirical data sets in several methodological studies. OrthoMaM is available for browsing, query and complete or filtered downloads at http://www.orthomam.univ-montp2.fr/.

OHP-027 Defining an integration process of personalised genomic medicine in clinic

BackgroundPersonalised medicine is based on availability of diagnostic biomarkers, but its future is strongly based on genomics. Genome sequencing may offer all this information but contests with properly analysed data....

Kazusa Marker DataBase: a database for genomics, genetics, and molecular breeding in plants.

In order to provide useful genomic information for agronomical plants, we have established a database, the Kazusa Marker DataBase (http://marker.kazusa.or.jp). This database includes information on DNA markers, e.g., SSR and SNP markers, genetic linkage maps, and physical maps, that were developed at the Kazusa DNA Research Institute. Keyword searches for the markers, sequence data used for marker development, and experimental conditions are also available through this database. Currently, 10 plant species have been targeted: tomato (Solanum lycopersicum), pepper (Capsicum annuum), strawberry (Fragaria × ananassa), radish (Raphanus sativus), Lotus japonicus, soybean (Glycine max), peanut (Arachis hypogaea), red clover (Trifolium pratense), white clover (Trifolium repens), and eucalyptus (Eucalyptus camaldulensis). In addition, the number of plant species registered in this database will be increased as our research progresses. The Kazusa Marker DataBase will be a useful tool for both basic and applied sciences, such as genomics, genetics, and molecular breeding in crops.

Identification and early diagnosis for traditional Chinese medicine-induced liver injury based on translational toxicology

Recently traditional Chinese medicine (TCM)-induced liver injury has been an unresolved critical issue which impacts TCM clinical safety. The premise and key step to reduce or avoid drug-induced liver injury (DILI) is to identify the drug source of liver injury in early stage. Then the timely withdrawal of drug and treatment can be done. However, the current diagnosis of DILI is primarily governed by exclusive method relying on administering history supplied by patients and experience judgment from doctors, which lacks objective and reliable diagnostic indices. It is obvious that diagnosis of TCM-induced liver injury is especially difficult due to the complicated composition of TCM medication, as well the frequent combination of Chinese and Western drugs in clinic. In this paper, we proposed construction of research pattern and method for objective identification of TCM-related DILI based on translational toxicology, which utilizes clinical specimen to find specific biomarkers and characteristic blood-entering constituents, as well the clinical biochemistry and liver biopsy. With integration of diagnosis marker database, bibliographic database, medical record database and clinical specimen database, an integrative diagnosis database for TCM-related DILI can be established, which would make a transformation of clinical identification pattern for TCM-induced liver injury from subjective and exclusive to objective and index-supporting mode. This would be helpful to improve rational uses of TCM and promote sustainable development of TCM industry.

First whole genome based microsatellite DNA marker database of tomato for mapping and variety identification

BackgroundThe cultivated tomato is second most consumed vegetable of the world and is an important part of a diverse and balanced diet as a rich source of vitamins, minerals, phenolic antioxidants and antioxidant lycopene having anti-cancer properties. To reap benefit of genomics of the domestic tomato (Solanum lycopersicum L.) unravelled by Tomato Genome Consortium (The Tomato Genome Consortium, 2012), the bulk mining of its markers in totality is imperative and critically required. The solgenomics has limited number of microsatellite DNA markers (2867) pertaining to solanaceae family. As these markers are of linkage map having relative distance, the choice of selected markers based on absolute distance as of physical map is missing. Only limited microsatellite markers with limitations are reported for variety identification thus there is a need for more markers supplementing DUS test and also for traceability of product in global market.DescriptionWe present here the first whole genome based microsatellite DNA marker database of tomato, TomSatDB (Tomato MicroSatellite Database) with more than 1.4 million markers mined in-silico, using MIcroSAtellite (MISA) tool. To cater the customized needs of wet lab, features with a novelty of an automated primer designing tool is added. TomSatDB (http://cabindb.iasri.res.in/tomsatdb), a user-friendly and freely accessible tool offers chromosome wise as well as location wise search of primers. It is an online relational database based on “three-tier architecture” that catalogues information of microsatellites in MySQL and user-friendly interface developed using PHP (Hypertext Pre Processor).ConclusionBesides abiotic stress, tomato is known to have biotic stress due to its susceptibility over 200 diseases caused by pathogenic fungi, bacteria, viruses and nematodes. These markers are expected to pave the way of germplasm management over abiotic and biotic stress as well as improvement through molecular breeding, leading to increased tomato productivity in India as well as other parts of the world. In era of IPR the new variety can be identified based on allelic variation among varieties supplementing DUS test and product traceability.

A comprehensive meta QTL analysis for fiber quality, yield, yield related and morphological traits, drought tolerance, and disease resistance in tetraploid cotton

BackgroundThe study of quantitative trait loci (QTL) in cotton (Gossypium spp.) is focused on traits of agricultural significance. Previous studies have identified a plethora of QTL attributed to fiber quality, disease and pest resistance, branch number, seed quality and yield and yield related traits, drought tolerance, and morphological traits. However, results among these studies differed due to the use of different genetic populations, markers and marker densities, and testing environments. Since two previous meta-QTL analyses were performed on fiber traits, a number of papers on QTL mapping of fiber quality, yield traits, morphological traits, and disease resistance have been published. To obtain a better insight into the genome-wide distribution of QTL and to identify consistent QTL for marker assisted breeding in cotton, an updated comparative QTL analysis is needed.ResultsIn this study, a total of 1,223 QTL from 42 different QTL studies in Gossypium were surveyed and mapped using Biomercator V3 based on the Gossypium consensus map from the Cotton Marker Database. A meta-analysis was first performed using manual inference and confirmed by Biomercator V3 to identify possible QTL clusters and hotspots. QTL clusters are composed of QTL of various traits which are concentrated in a specific region on a chromosome, whereas hotspots are composed of only one trait type. QTL were not evenly distributed along the cotton genome and were concentrated in specific regions on each chromosome. QTL hotspots for fiber quality traits were found in the same regions as the clusters, indicating that clusters may also form hotspots.ConclusionsPutative QTL clusters were identified via meta-analysis and will be useful for breeding programs and future studies involving Gossypium QTL. The presence of QTL clusters and hotspots indicates consensus regions across cultivated tetraploid Gossypium species, environments, and populations which contain large numbers of QTL, and in some cases multiple QTL associated with the same trait termed a hotspot. This study combines two previous meta-analysis studies and adds all other currently available QTL studies, making it the most comprehensive meta-analysis study in cotton to date.

Zebrafish midbrain slow-amplifying progenitors exhibit high levels of transcripts for nucleotide and ribosome biogenesis

Investigating neural stem cell (NSC) behaviour in vivo, which is a major area of research, requires NSC models to be developed. We carried out a multilevel characterisation of the zebrafish embryo peripheral midbrain layer (PML) and identified a unique vertebrate progenitor population. Located dorsally in the transparent embryo midbrain, these large slow-amplifying progenitors (SAPs) are accessible for long-term in vivo imaging. They form a neuroepithelial layer adjacent to the optic tectum, which has transitory fast-amplifying progenitors (FAPs) at its margin. The presence of these SAPs and FAPs in separate domains provided the opportunity to data mine the ZFIN expression pattern database for SAP markers, which are co-expressed in the retina. Most of them are involved in nucleotide synthesis, or encode nucleolar and ribosomal proteins. A mutant for the cad gene, which is strongly expressed in the PML, reveals severe midbrain defects with massive apoptosis and sustained proliferation. We discuss how fish midbrain and retina progenitors might derive from ancient sister cell types and have specific features that are not shared with other SAPs.

CottonGen: a genomics, genetics and breeding database for cotton research

CottonGen (http://www.cottongen.org) is a curated and integrated web-based relational database providing access to publicly available genomic, genetic and breeding data for cotton. CottonGen supercedes CottonDB and the Cotton Marker Database, with enhanced tools for easier data sharing, mining, visualization and data retrieval of cotton research data. CottonGen contains annotated whole genome sequences, unigenes from expressed sequence tags (ESTs), markers, trait loci, genetic maps, genes, taxonomy, germplasm, publications and communication resources for the cotton community. Annotated whole genome sequences of Gossypium raimondii are available with aligned genetic markers and transcripts. These whole genome data can be accessed through genome pages, search tools and GBrowse, a popular genome browser. Most of the published cotton genetic maps can be viewed and compared using CMap, a comparative map viewer, and are searchable via map search tools. Search tools also exist for markers, quantitative trait loci (QTLs), germplasm, publications and trait evaluation data. CottonGen also provides online analysis tools such as NCBI BLAST and Batch BLAST.

Tantulocarida versus Thecostraca: inside or outside? First attempts to resolve phylogenetic position of Tantulocarida using gene sequences

Complete 18S rDNA sequences of two species of the Tantulocarida Arcticotantulus pertzovi (Basipodellidae) and Microdajus tchesunovi (Microdajidae) were obtained and used for estimating the relationship of the class with other Crustacea. This constitutes the first use of tantulocaridan gene sequences, and we conclude that the Tantulocarida are very close relatives of the class Thecostraca, which comprise cirripedes, ascothoracidans and the enigmatic facetotectans. With much lower confidence, the Tantulocarida are also indicated as nested within the Thecostraca, being sister group to the Cirripedia. We therefore discuss morphological similarities and differences between tantulocaridans and the thecostracans in search of potential synapomorphies, including a possible relation to the parasitic barnacles (Rhizocephala). We conclude that the cement gland of the tantulus larva and the cirripede cyprid might be homologous structures, but that similarities in host infection and root systems between the Tantulocarida and the Rhizocephala are, on present evidence, likely to be homoplasies evolved by convergent evolution into advanced parasitism. The precise position of the Tantulocarida in relation to or within the Thecostraca must be pursued by a more extensive database of genetic markers.

Improving pasture intake predictions by variable weighting of plant marker concentrations

It is difficult to measure pasture feed intake. A common method is based on naturally occurring, indigestible plant markers, such as long chain alkanes. Least-squares procedures are used to estimate diet composition and intake. If actual intake of a supplement is known, then total intake and the intake of all dietary components can be estimated. This ‘labelled-supplement’ approach requires an estimate of the faecal recoveries of the markers. The accuracy and precision of intake solutions for each animal is also affected by the sampling and measurement precision of the plant and faecal marker concentrations. This work was conducted to study whether weighting each marker's sums of squares in the least-squares procedure could be used to provide a more robust solution.Cluster and discriminant analyses of a plant marker database determined the contribution of each marker to discrimination between categories of plants. The markers’ cluster or discriminant weights were used to weight the sums of squares in the least squares procedures. The actual individual dry matter intakes (DMI) of 20 cattle were arbitrarily assigned for three different diets. Measurement and sampling variations in marker concentrations and/or faecal recoveries were simulated to generate predicted total pasture intakes around the actual values.Six marker weighting methods were compared for their DMI prediction error values and correlations between predicted and actual DMI: (A) all markers weighted by one; (B) separate cluster analyses of z scores for alkanes and alcohols; (C) combined cluster analyses for alkanes and alcohols; (D) discriminant analyses of z score marker data for plants categorized into grasses, legumes, shrubs and trees; (E) discriminant analyses of plants categorized on origin and plant, photosynthesis and reproduction type; and (F) discriminant analyses of plants categorized on plant, photosynthesis and reproduction type.The standard approach of weighting all markers by one (A) was satisfactory when marker concentration error was set at zero, however intake predictions were poor when the error was non-zero, which is likely. The weighted least-squares intake solutions that were more robust to variance in measured marker concentrations or in assumed faecal recovery rates were those using weights derived by methods D and F. Marker weights from Methods D, E and F resulted in similar intake prediction error variances and correlations. Methods E and F required more botanical information about plant species and method D was simpler, so method D is recommended rather than other methods studied here, including the standard method A. There are problems with using weights derived from an analysis of all published marker data, so better weighting methods may still be found for specific plant and marker datasets.

NABIC marker database: A molecular markers information network of agricultural crops.

In 2013, National Agricultural Biotechnology Information Center (NABIC) reconstructs a molecular marker database for useful genetic resources. The web-based marker database consists of three major functional categories: map viewer, RSN marker and gene annotation. It provides 7250 marker locations, 3301 RSN marker property, 3280 molecular marker annotation information in agricultural plants. The individual molecular marker provides information such as marker name, expressed sequence tag number, gene definition and general marker information. This updated marker-based database provides useful information through a user-friendly web interface that assisted in tracing any new structures of the chromosomes and gene positional functions using specific molecular markers.AvailabilityThe database is available for free at http://nabic.rda.go.kr/gere/rice/molecularMarkers/

FmMDb: A Versatile Database of Foxtail Millet Markers for Millets and Bioenergy Grasses Research

The prominent attributes of foxtail millet (Setaria italica L.) including its small genome size, short life cycle, inbreeding nature, and phylogenetic proximity to various biofuel crops have made this crop an excellent model system to investigate various aspects of architectural, evolutionary and physiological significances in Panicoid bioenergy grasses. After release of its whole genome sequence, large-scale genomic resources in terms of molecular markers were generated for the improvement of both foxtail millet and its related species. Hence it is now essential to congregate, curate and make available these genomic resources for the benefit of researchers and breeders working towards crop improvement. In view of this, we have constructed the Foxtail millet Marker Database (FmMDb; http://www.nipgr.res.in/foxtail.html), a comprehensive online database for information retrieval, visualization and management of large-scale marker datasets with unrestricted public access. FmMDb is the first database which provides complete marker information to the plant science community attempting to produce elite cultivars of millet and bioenergy grass species, thus addressing global food insecurity.

Expression profiling of Aldh1l1‐precursors in the developing spinal cord reveals glial lineage‐specific genes and direct Sox9‐Nfe2l1 interactions

Developmental regulation of gliogenesis in the mammalian CNS is incompletely understood, in part due to a limited repertoire of lineage-specific genes. We used Aldh1l1-GFP as a marker for gliogenic radial glia and later-stage precursors of developing astrocytes and performed gene expression profiling of these cells. We then used this dataset to identify candidate transcription factors that may serve as glial markers or regulators of glial fate. Our analysis generated a database of developmental stage-related markers of Aldh1l1+ cells between murine embryonic day 13.5-18.5. Using these data we identify the bZIP transcription factor Nfe2l1 and demonstrate that it promotes glial fate under direct Sox9 regulatory control. Thus, this dataset represents a resource for identifying novel regulators of glial development.

A Phylum-Level Bacterial Phylogenetic Marker Database

Large-scale, genome-level molecular phylogenetic analyses present both opportunities and challenges for bacterial evolutionary and ecological studies. We constructed a phylum-level bacterial phylogenetic marker database by surveying all complete bacterial genomes and identifying single-copy genes that were widely distributed in each of the 20 bacterial phyla. We showed that phylum trees made using these markers were highly resolved and were more robust than the bacterial genome tree based on 31 universal bacterial marker genes. In addition, using the Global Ocean Sampling data set as an example, we demonstrated that the expanded marker database greatly increased the power of metagenomic phylotyping. We incorporated the database into an automated phylogenomic inference application (Phyla-AMPHORA) and made it publicly available. We believe that this centralized resource should have broad applicability in bacterial systematics, phylogenetics, and metagenomic studies.