Non-redundant Protein Database Research Articles

Genes regulating lipid and protein metabolism are highly expressed in mammary gland of lactating dairy goats.

Dairy goats serve as an important source of milk and also fulfill agricultural and economic roles in developing countries. Understanding the genetic background of goat mammary gland is important for research on the regulatory mechanisms controlling tissue function and the synthesis of milk components. We collected tissue at four different stages of goat mammary gland development and generated approximately 25 GB of data from Illumina de novo RNA sequencing. The combined reads were assembled into 51,361 unigenes, and approximately 60.07 % of the unigenes had homology to other proteins in the NCBI non-redundant protein database (NR). Functional classification through eukaryotic Ortholog Groups of Protein (KOG), gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that the unigenes from goat mammary glands are involved in a wide range of biological processes and metabolic pathways, including lipid metabolism and lactose metabolism. The results of qPCR revealed that genes encoding FABP3, FASN, SCD, PLIN2, whey proteins (LALBA and BLG), and caseins (CSN1S1, CSN1S2, CSN2 and CSN3) at 100 and 310 days postpartum increased significantly compared with the non-lactating period. In addition to their role in lipid and protein synthesis, the higher expression at 310 days postpartum could contribute to mammary cell turnover during pregnancy. In conclusion, this is the first study to characterize the complete transcriptome of goat mammary glands and constitutes a comprehensive genomic resource available for further studies of ruminant lactation.

De novo assembly and characterization of the transcriptome of seagrass Zostera marina using Illumina paired-end sequencing.

BackgroundThe seagrass Zostera marina is a monocotyledonous angiosperm belonging to a polyphyletic group of plants that can live submerged in marine habitats. Zostera marina L. is one of the most common seagrasses and is considered a cornerstone of marine plant molecular ecology research and comparative studies. However, the mechanisms underlying its adaptation to the marine environment still remain poorly understood due to limited transcriptomic and genomic data.Principal FindingsHere we explored the transcriptome of Z. marina leaves under different environmental conditions using Illumina paired-end sequencing. Approximately 55 million sequencing reads were obtained, representing 58,457 transcripts that correspond to 24,216 unigenes. A total of 14,389 (59.41%) unigenes were annotated by blast searches against the NCBI non-redundant protein database. 45.18% and 46.91% of the unigenes had significant similarity with proteins in the Swiss-Prot database and Pfam database, respectively. Among these, 13,897 unigenes were assigned to 57 Gene Ontology (GO) terms and 4,745 unigenes were identified and mapped to 233 pathways via functional annotation against the Kyoto Encyclopedia of Genes and Genomes pathway database (KEGG). We compared the orthologous gene family of the Z. marina transcriptome to Oryza sativa and Pyropia yezoensis and 11,667 orthologous gene families are specific to Z. marina. Furthermore, we identified the photoreceptors sensing red/far-red light and blue light. Also, we identified a large number of genes that are involved in ion transporters and channels including Na+ efflux, K+ uptake, Cl− channels, and H+ pumping.ConclusionsOur study contains an extensive sequencing and gene-annotation analysis of Z. marina. This information represents a genetic resource for the discovery of genes related to light sensing and salt tolerance in this species. Our transcriptome can be further utilized in future studies on molecular adaptation to abiotic stress in Z. marina.

De novo Assembly of the Grass Carp Ctenopharyngodon idella Transcriptome to Identify miRNA Targets Associated with Motile Aeromonad Septicemia

Background De novo transcriptome sequencing is a robust method of predicting miRNA target genes, especially for organisms without reference genomes. Differentially expressed miRNAs had been identified previously in kidney samples collected from susceptible and resistant grass carp (Ctenopharyngodon idella) affected by Aeromonas hydrophila. Target identification for these differentially expressed miRNAs poses a major challenge in this non-model organism.ResultsTwo cDNA libraries constructed from mRNAs of susceptible and resistant C. idella were sequenced by Illumina Hiseq 2000 technology. A total of more than 100 million reads were generated and de novo assembled into 199,593 transcripts which were further extensively annotated by comparing their sequences to different protein databases. Biochemical pathways were predicted from these transcript sequences. A BLASTx analysis against a non-redundant protein database revealed that 61,373 unigenes coded for 28,311 annotated proteins. Two cDNA libraries from susceptible and resistant samples showed that 721 unigenes were expressed at significantly different levels; 475 were significantly up-regulated and 246 were significantly down-regulated in the SG samples compared to the RG samples. The computational prediction of miRNA targets from these differentially expressed genes identified 188 unigenes as the targets of 5 conserved and 4 putative novel miRNA families.ConclusionThis study demonstrates the feasibility of identifying miRNA targets by transcriptome analysis. The transcriptome assembly data represent a substantial increase in the genomic resources available for C. idella and will provide insights into the gene expression profile analysis and the miRNA function annotations in further studies.

A comprehensive transcriptome provides candidate genes for sex determination/differentiation and SSR/SNP markers in yellow catfish.

Sex dimorphic growth pattern has significant theory and application implications in fish. Recently, a Y- and X-specific allele marker-assisted sex control technique has been developed for mass production of all-male population in yellow catfish (Pelteobagrus fulvidraco), but the genetic information for sex determination and sex control breeding has remained unclear. Here, we attempted to provide the first insight into a comprehensive transcriptome covering multiple tissues from XX females, XY males, and YY super-males of yellow catfish by using 454 GS-FLX platform, for a better assembly and gene coverage. A total of 1,202,933 high quality reads (about 540Mbp) were obtained and assembled into 28,297 contigs and 141,951 singletons. BLASTX searches against the NCBI non-redundant protein database (nr) led a total of 52,564 unique sequences including 18,748 contigs and 33,816 singletons to match 25,669 known or predicted unique proteins. All of them with annotated function were categorized by gene ontology (GO) analysis, and 712 were assigned to reproduction and reproductive process. Some potential genes relevant to reproductive system including steroid hormone biosynthesis and GnRH (gonadotropin-releasing hormone) signaling pathway were further identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis; and at least 21 sex determination and differentiation-related genes, such as Dmrt1, Sox9a/b, Cyp19b, WT1, and AMH were identified and characterized. Additionally, a total of 82,794 simple sequence repeats (SSRs), 26,450 single nucleotide polymorphisms (SNPs), and 4,145 insertions and deletions (INDELs) were revealed from the transcriptome data. Therefore, the current transcriptome resources highlight further studies on sex-control breeding in yellow catfish and will benefit future studies on reproduction and sex determination in teleost fish.

Estrogen alters the profile of the transcriptome in river snail Bellamya aeruginosa.

We evaluated the transcriptome dynamics of the freshwater river snail Bellamya aeruginosa exposed to 17β-estradiol (E2) using the Roche/454 GS-FLX platform. In total, 41,869 unigenes, with an average length of 586bp, representing 36,181 contigs and 5,688 singlets were obtained. Among them, 18.08, 36.85, and 25.47% matched sequences in the GenBank non-redundant nucleic acid database, non-redundant protein database, and Swiss protein database, respectively. Annotation of the unigenes with gene ontology, and then mapping them to biological pathways, revealed large groups of genes related to growth, development, reproduction, signal transduction, and defense mechanisms. Significant differences were found in gene expression in both liver and testicular tissues between control and E2-exposed organisms. These changes in gene expression will help in understanding the molecular mechanisms of the response to physiological stress in the river snail exposed to estrogen, and will facilitate research into biological processes and underlying physiological adaptations to xenoestrogen exposure in gastropods.

Transcriptomic response to estrogen exposure in the male Zhikong scallop, Chlamys farreri

The transcriptomes of Zhikong scallop exposed to 17β-estradiol were determined using the Roche/454. A total of 51,997 unigenes, representing 45,030 contigs and 6967 singlets were obtained. And 14,028, 19,798 and 14,981 of these unigenes were annotated from the non-redundant nucleic acid database, non-redundant protein database and Swiss protein database, respectively. A total of 10,699 unigenes were further annotated to biological processes (9080), molecular functions (8692) and cellular components (7829) using the GO, and 8945 unigenes were mapped to biological pathways including the metabolism (2862) and genetic information processing (2263). Most importantly, 16,692 unigenes and 18,686 unigenes in testis, and 10,492 unigenes and 13,186 unigenes in digestive gland were up-regulated significantly after exposure to 50 and 500ngE2/L; while 10,212 unigenes and 9409 unigenes in testis and 10,629 unigenes and 9463 unigenes in digestive gland were down-regulated. These valuable information provides insights into the mechanisms in invertebrate exposure to EDCs.

A taxonomy of bacterial microcompartment loci constructed by a novel scoring method.

Bacterial microcompartments (BMCs) are proteinaceous organelles involved in both autotrophic and heterotrophic metabolism. All BMCs share homologous shell proteins but differ in their complement of enzymes; these are typically encoded adjacent to shell protein genes in genetic loci, or operons. To enable the identification and prediction of functional (sub)types of BMCs, we developed LoClass, an algorithm that finds putative BMC loci and inventories, weights, and compares their constituent pfam domains to construct a locus similarity network and predict locus (sub)types. In addition to using LoClass to analyze sequences in the Non-redundant Protein Database, we compared predicted BMC loci found in seven candidate bacterial phyla (six from single-cell genomic studies) to the LoClass taxonomy. Together, these analyses resulted in the identification of 23 different types of BMCs encoded in 30 distinct locus (sub)types found in 23 bacterial phyla. These include the two carboxysome types and a divergent set of metabolosomes, BMCs that share a common catalytic core and process distinct substrates via specific signature enzymes. Furthermore, many Candidate BMCs were found that lack one or more core metabolosome components, including one that is predicted to represent an entirely new paradigm for BMC-associated metabolism, joining the carboxysome and metabolosome. By placing these results in a phylogenetic context, we provide a framework for understanding the horizontal transfer of these loci, a starting point for studies aimed at understanding the evolution of BMCs. This comprehensive taxonomy of BMC loci, based on their constituent protein domains, foregrounds the functional diversity of BMCs and provides a reference for interpreting the role of BMC gene clusters encoded in isolate, single cell, and metagenomic data. Many loci encode ancillary functions such as transporters or genes for cofactor assembly; this expanded vocabulary of BMC-related functions should be useful for design of genetic modules for introducing BMCs in bioengineering applications.

De novo assembly of Eugenia uniflora L. transcriptome and identification of genes from the terpenoid biosynthesis pathway

Pitanga (Eugenia uniflora L.) is a member of the Myrtaceae family and is of particular interest due to its medicinal properties that are attributed to specialized metabolites with known biological activities. Among these molecules, terpenoids are the most abundant in essential oils that are found in the leaves and represent compounds with potential pharmacological benefits. The terpene diversity observed in Myrtaceae is determined by the activity of different members of the terpene synthase and oxidosqualene cyclase families. Therefore, the aim of this study was to perform a de novo assembly of transcripts from E. uniflora leaves and to annotation to identify the genes potentially involved in the terpenoid biosynthesis pathway and terpene diversity. In total, 72,742 unigenes with a mean length of 1048bp were identified. Of these, 43,631 and 36,289 were annotated with the NCBI non-redundant protein and Swiss-Prot databases, respectively. The gene ontology categorized the sequences into 53 functional groups. A metabolic pathway analysis with KEGG revealed 8,625 unigenes assigned to 141 metabolic pathways and 40 unigenes predicted to be associated with the biosynthesis of terpenoids. Furthermore, we identified four putative full-length terpene synthase genes involved in sesquiterpenes and monoterpenes biosynthesis, and three putative full-length oxidosqualene cyclase genes involved in the triterpenes biosynthesis. The expression of these genes was validated in different E. uniflora tissues.

Characterization of the global transcriptome using Illumina sequencing and novel microsatellite marker information in seashore paspalum

Seashore paspalum (Paspalum vaginatum O. Swartz) is a halophytic warm-season perennial grass, which plays an important role in protection of environment. However, very limited transcriptomic and genomic information are currently available for seashore paspalum. In this study, the seashore paspalum transcriptome were sequenced using Illumina paired-end sequencing technology. In total, 32,603 unigenes with an average length of 970 bp were obtained by de novo assembly. Of the unigenes, 25,411 unigenes (77.94 %) had significant similarity with known proteins in the NCBI non-redundant protein and Swiss-Prot databases. Of these annotated unigenes, 20,962 and 10,620 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. A total of 4,699 unigenes were mapped into 118 Kyoto Encyclopedia of Genes and Genomes pathways. In addition, 3,010 potential simple sequence repeats (SSRs) were predicted for microsatellite analyse. Tri-nucleotide was the dominant repeat (1,583, 52.58 %), followed by di-nucleotide (975, 32.39 %) and tetra-nucleotide (217, 7.21 %). Fifty SSR sites were randomly selected for validation and development of EST–SSR markers. This study provided the global sequence data for seashore paspalum and demonstrated that the Illumina paired-end sequencing is a fast and cost-effective approach to gene discovery and molecular marker development.

Transcriptome sequencing and identification of cold tolerance genes in hardy Corylus species (C. heterophylla Fisch) floral buds.

BackgroundThe genus Corylus is an important woody species in Northeast China. Its products, hazelnuts, constitute one of the most important raw materials for the pastry and chocolate industry. However, limited genetic research has focused on Corylus because of the lack of genomic resources. The advent of high-throughput sequencing technologies provides a turning point for Corylus research. In the present study, we performed de novo transcriptome sequencing for the first time to produce a comprehensive database for the Corylus heterophylla Fisch floral buds.ResultsThe C. heterophylla Fisch floral buds transcriptome was sequenced using the Illumina paired-end sequencing technology. We produced 28,930,890 raw reads and assembled them into 82,684 contigs. A total of 40,941 unigenes were identified, among which 30,549 were annotated in the NCBI Non-redundant (Nr) protein database and 18,581 were annotated in the Swiss-Prot database. Of these annotated unigenes, 25,311 and 10,514 unigenes were assigned to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. We could map 17,207 unigenes onto 128 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) database. Additionally, based on the transcriptome, we constructed a candidate cold tolerance gene set of C. heterophylla Fisch floral buds. The expression patterns of selected genes during four stages of cold acclimation suggested that these genes might be involved in different cold responsive stages in C. heterophylla Fisch floral buds.ConclusionThe transcriptome of C. heterophylla Fisch floral buds was deep sequenced, de novo assembled, and annotated, providing abundant data to better understand the C. heterophylla Fisch floral buds transcriptome. Candidate genes potentially involved in cold tolerance were identified, providing a material basis for future molecular mechanism analysis of C. heterophylla Fisch floral buds tolerant to cold stress.

De novo transcriptome assembly for rudimentary leaves in Litchi chinesis Sonn. and identification of differentially expressed genes in response to reactive oxygen species.

BackgroundLitchi is an evergreen woody tree widely cultivated in subtropical and tropical regions. Defective flowering is a major challenge for litchi production in time of climate change and global warming. Previous studies have shown that high temperature conditions encourage the growth of rudimentary leaves in panicles and suppress litchi flowering, while reactive oxygen species (ROS) generated by methyl viologen dichloride hydrate (MV) promote flowering and abortion of rudimentary leaves. To understand the molecular function of the ROS-induced abortion of rudimentary leaves in litchi, we sequenced and de novo assembled the litchi transcriptome.ResultsOur assembly encompassed 82,036 unigenes with a mean size of 710 bp, and over 58% (47,596) of unigenes showed significant similarities to known sequences in GenBank non-redundant (nr) protein database. 5,865 unigenes were found to be differentially expressed between ROS-treated and un-treated rudimentary leaves, and genes encoding signaling components of plant hormones such as ABA and ethylene were significantly enriched.ConclusionOur transcriptome data represents the comprehensive collection of expressed sequence tags (ESTs) of litchi leaves, which is a vital resource for future studies on the genomics of litchi and other closely related species. The identified differentially expressed genes also provided potential candidates for functional analysis of genes involved in litchi flowering underlying the control of rudimentary leaves in the panicles.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-805) contains supplementary material, which is available to authorized users.

ESTs analysis of putative genes engaged in Polyporus umbellatus sclerotial development.

Polyporus umbellatus is one of the most widely used and precious medicinal fungi and the underground sclerotia are known to be with great medicinal value. However, the molecular mechanisms involved in sclerotial development are poorly understood. In the present study, we constructed a forward suppression subtractive hybridization (SSH) cDNA library of Polyporus umbellatus to identify genes expressing differently between mycelium and sclerotia. In this library, a total of 1202 clones were sequenced, assembled into 222 contigs and 524 singletons which were further searched against the NCBI nonredundant (NR) protein database (E-value cutoff, 10−5). Based on sequence similarity with known proteins, 378 sequences between mycelium and sclerotial were identified and classified into different functional categories through Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs). We have finally identified a majority of differentially expressed genes (constituting 5.6% of the present library) between the two different periods. An expression level of 32 selected expressed sequence tags (ESTs) generated from the above SSH cDNA library was studied through RT-PCR. This study provides the first global overview of genes putatively involved in Polyporus umbellatus sclerotial development and provides a preliminary basis for further functional research in terms of regulated gene expression in sclerotial production.

Microbial community diversity and physical-chemical features of the Southwestern Atlantic Ocean.

Microbial oceanography studies have demonstrated the central role of microbes in functioning and nutrient cycling of the global ocean. Most of these former studies including at Southwestern Atlantic Ocean (SAO) focused on surface seawater and benthic organisms (e.g., coral reefs and sponges). This is the first metagenomic study of the SAO. The SAO harbors a great microbial diversity and marine life (e.g., coral reefs and rhodolith beds). The aim of this study was to characterize the microbial community diversity of the SAO along the depth continuum and different water masses by means of metagenomic, physical-chemical and biological analyses. The microbial community abundance and diversity appear to be strongly influenced by the temperature, dissolved organic carbon, and depth, and three groups were defined [1. surface waters; 2. sub-superficial chlorophyll maximum (SCM) (48-82 m) and 3. deep waters (236-1,200 m)] according to the microbial composition. The microbial communities of deep water masses [South Atlantic Central water, Antarctic Intermediate water and Upper Circumpolar Deep water] are highly similar. Of the 421,418 predicted genes for SAO metagenomes, 36.7 % had no homologous hits against 17,451,486 sequences from the North Atlantic, South Atlantic, North Pacific, South Pacific and Indian Oceans. From these unique genes from the SAO, only 6.64 % had hits against the NCBI non-redundant protein database. SAO microbial communities share genes with the global ocean in at least 70 cellular functions; however, more than a third of predicted SAO genes represent a unique gene pool in global ocean. This study was the first attempt to characterize the taxonomic and functional community diversity of different water masses at SAO and compare it with the microbial community diversity of the global ocean, and SAO had a significant portion of endemic gene diversity. Microbial communities of deep water masses (236-1,200 m) are highly similar, suggesting that these water masses have very similar microbiological attributes, despite the common knowledge that water masses determine prokaryotic community and are barriers to microbial dispersal. The present study also shows that SCM is a clearly differentiated layer within Tropical waters with higher abundance of phototrophic microbes and microbial diversity.

Transcriptome analysis of the mud crab (Scylla paramamosain) by 454 deep sequencing: assembly, annotation, and marker discovery.

In this study, we reported the characterization of the first transcriptome of the mud crab (Scylla paramamosain). Pooled cDNAs of four tissue types from twelve wild individuals were sequenced using the Roche 454 FLX platform. Analysis performed included de novo assembly of transcriptome sequences, functional annotation, and molecular marker discovery. A total of 1,314,101 high quality reads with an average length of 411 bp were generated by 454 sequencing on a mixed cDNA library. De novo assembly of these 1,314,101 reads produced 76,778 contigs (consisting of 818,154 reads) with 5.4-fold average sequencing coverage. The remaining 495,947 reads were singletons. A total of 78,268 unigenes were identified based on sequence similarity with known proteins (E≤0.00001) in UniProt and non-redundant protein databases. Meanwhile, 44,433 sequences were identified (E≤0.00001) using a BLASTN search against the NCBI nucleotide database. Gene Ontology (GO) analysis indicated that biosynthetic process, cell part, and ion binding were the most abundant terms in biological process, cellular component, and molecular function categories, respectively. Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis revealed that 4,878 unigenes distributed in 281 different pathways. In addition, 19,011 microsatellites and 37,063 potential single nucleotide polymorphisms were detected from the transcriptome of S. paramamosain. Finally, thirty polymorphic microsatellite markers were developed and used to assess genetic diversity of a wild population of S. paramamosain. So far, existing sequence resources for S. paramamosain are extremely limited. The present study provides a characterization of transcriptome from multiple tissues and individuals, as well as an assessment of genetic diversity of a wild population. These sequence resources will facilitate the investigation of population genetic diversity, the development of genetic maps, and the conduct of molecular marker-assisted breeding in S. paramamosain and related crab species.

De novo assembly and transcriptome analysis of the rubber tree (Hevea brasiliensis) and SNP markers development for rubber biosynthesis pathways.

Hevea brasiliensis (Willd. Ex Adr. Juss.) Muell.-Arg. is the primary source of natural rubber that is native to the Amazon rainforest. The singular properties of natural rubber make it superior to and competitive with synthetic rubber for use in several applications. Here, we performed RNA sequencing (RNA-seq) of H. brasiliensis bark on the Illumina GAIIx platform, which generated 179,326,804 raw reads on the Illumina GAIIx platform. A total of 50,384 contigs that were over 400 bp in size were obtained and subjected to further analyses. A similarity search against the non-redundant (nr) protein database returned 32,018 (63%) positive BLASTx hits. The transcriptome analysis was annotated using the clusters of orthologous groups (COG), gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Pfam databases. A search for putative molecular marker was performed to identify simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). In total, 17,927 SSRs and 404,114 SNPs were detected. Finally, we selected sequences that were identified as belonging to the mevalonate (MVA) and 2-C-methyl-D-erythritol 4-phosphate (MEP) pathways, which are involved in rubber biosynthesis, to validate the SNP markers. A total of 78 SNPs were validated in 36 genotypes of H. brasiliensis. This new dataset represents a powerful information source for rubber tree bark genes and will be an important tool for the development of microsatellites and SNP markers for use in future genetic analyses such as genetic linkage mapping, quantitative trait loci identification, investigations of linkage disequilibrium and marker-assisted selection.

De novo transcriptome assembly from inflorescence of Orchis italica: analysis of coding and non-coding transcripts.

The floral transcriptome of Orchis italica, a wild orchid species, was obtained using Illumina RNA-seq technology and specific de novo assembly and analysis tools. More than 100 million raw reads were processed resulting in 132,565 assembled transcripts and 86,079 unigenes with an average length of 606 bp and N50 of 956 bp. Functional annotation assigned 38,984 of the unigenes to records present in the NCBI non-redundant protein database, 32,161 of them to Gene Ontology terms, 15,775 of them to Eukaryotic Orthologous Groups (KOG) and 7,143 of them to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The in silico expression analysis based on the Fragments Per Kilobase of transcript per Million mapped reads (FPKM) was confirmed by real-time RT-PCR experiments on 10 selected unigenes, which showed high and statistically significant positive correlation with the RNA-seq based expression data. The prediction of putative long non-coding RNAs was assessed using two different software packages, CPC and Portrait, resulting in 7,779 unannotated unigenes that matched the threshold values for both of the analyses. Among the predicted long non-coding RNAs, one is the homologue of TAS3, a long non-coding RNA precursor of trans-acting small interfering RNAs (ta-siRNAs). The differential expression pattern observed for the selected putative long non-coding RNAs suggests their possible functional role in different floral tissues.

Transcriptome of tung tree mature seeds with an emphasis on lipid metabolism genes

Tung oil, the major product of tung tree (Vernicia fordii) seeds, is one of the highest quality oils for industrial applications and has been considered for the production of biodiesel. Considering the poor agronomical traits of this crop, efforts have been made to breed tung trees for a higher fruit yield and oil property modification for biodiesel use or to engineer plants to produce a higher tung oil yield. However, these efforts have been hampered by a lack of molecular information, as there is no available genome and identified and characterized transcripts of this tree are scarce. Furthermore, there are still many knowledge gaps regarding tung oil biosynthesis. To provide a comprehensive and accurate foundation for molecular studies of tung tree, we present here a reference transcriptome dataset of mature tung seeds. A set of 43,081,927 reads were assembled into 47,585 unigenes. A homology search using blastx against the GenBank nonredundant protein database and the Swiss-Prot database resulted in the annotation of 96 and 81 % of these unigenes, respectively. We also systematically arranged a series of unigenes potentially associated with oil biosynthesis and degradation and examined the expression profile of a subset of those genes in samples from five different stages of seed development, providing a valuable source of genes and transcriptional information related to these pathways. This study represents the first large-scale transcriptome annotation of tung tree and will be useful in tung breeding for oil properties and other agronomical traits.

De novo sequencing-based transcriptome and digital gene expression analysis reveals insecticide resistance-relevant genes in Propylaea japonica (Thunberg) (Coleoptea: Coccinellidae).

The ladybird Propylaea japonica (Thunberg) is one of most important natural enemies of aphids in China. This species is threatened by the extensive use of insecticides but genomics-based information on the molecular mechanisms underlying insecticide resistance is limited. Hence, we analyzed the transcriptome and expression profile data of P. japonica in order to gain a deeper understanding of insecticide resistance in ladybirds. We performed de novo assembly of a transcriptome using Illumina's Solexa sequencing technology and short reads. A total of 27,243,552 reads were generated. These were assembled into 81,458 contigs and 33,647 unigenes (6,862 clusters and 26,785 singletons). Of the unigenes, 23,965 (71.22%) have putative homologues in the non-redundant (nr) protein database from NCBI, using BLASTX, with a cut-off E-value of 10−5. We examined COG, GO and KEGG annotations to better understand the functions of these unigenes. Digital gene expression (DGE) libraries showed differences in gene expression profiles between two insecticide resistant strains. When compared with an insecticide susceptible profile, a total of 4,692 genes were significantly up- or down- regulated in a moderately resistant strain. Among these genes, 125 putative insecticide resistance genes were identified. To confirm the DGE results, 16 selected genes were validated using quantitative real time PCR (qRT-PCR). This study is the first to report genetic information on P. japonica and has greatly enriched the sequence data for ladybirds. The large number of gene sequences produced from the transcriptome and DGE sequencing will greatly improve our understanding of this important insect, at the molecular level, and could contribute to the in-depth research into insecticide resistance mechanisms.

Priming of protein expression in the defence response of Zantedeschia aethiopica to Pectobacterium carotovorum.

The defence response of Zantedeschia aethiopica, a natural rhizomatous host of the soft rot bacterium Pectobacterium carotovorum, was studied following the activation of common induced resistance pathways—systemic acquired resistance and induced systemic resistance. Proteomic tools were used, together with in vitro quantification and in situ localization of selected oxidizing enzymes. In total, 527 proteins were analysed by label-free mass spectrometry (MS) and annotated against the National Center for Biotechnology Information (NCBI) nonredundant (nr) protein database of rice (Oryza sativa). Of these, the fore most differentially expressed group comprised 215 proteins that were primed following application of methyl jasmonate (MJ) and subsequent infection with the pathogen. Sixty-five proteins were down-regulated following MJ treatments. The application of benzothiadiazole (BTH) increased the expression of 23 proteins; however, subsequent infection with the pathogen repressed their expression and did not induce priming. The sorting of primed proteins by Gene Ontology protein function category revealed that the primed proteins included nucleic acid-binding proteins, cofactor-binding proteins, ion-binding proteins, transferases, hydrolases and oxidoreductases. In line with the highlighted involvement of oxidoreductases in the defence response, we determined their activities, priming pattern and localization in planta. Increased activities were confined to the area surrounding the pathogen penetration site, associating these enzymes with the induced systemic resistance afforded by the jasmonic acid signalling pathway. The results presented here demonstrate the concerted priming of protein expression following MJ treatment, making it a prominent part of the defence response of Z. aethiopica to P. carotovorum.

Transcriptome sequencing and De Novo analysis of Youngia japonica using the illumina platform.

Youngia japonica, a weed species distributed worldwide, has been widely used in traditional Chinese medicine. It is an ideal plant for studying the evolution of Asteraceae plants because of its short life history and abundant source. However, little is known about its evolution and genetic diversity. In this study, de novo transcriptome sequencing was conducted for the first time for the comprehensive analysis of the genetic diversity of Y. japonica. The Y. japonica transcriptome was sequenced using Illumina paired-end sequencing technology. We produced 21,847,909 high-quality reads for Y. japonica and assembled them into contigs. A total of 51,850 unigenes were identified, among which 46,087 were annotated in the NCBI non-redundant protein database and 41,752 were annotated in the Swiss-Prot database. We mapped 9,125 unigenes onto 163 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database. In addition, 3,648 simple sequence repeats (SSRs) were detected. Our data provide the most comprehensive transcriptome resource currently available for Y. japonica. C4 photosynthesis unigenes were found in the biological process of Y. japonica. There were 5596 unigenes related to defense response and 1344 ungienes related to signal transduction mechanisms (10.95%). These data provide insights into the genetic diversity of Y. japonica. Numerous SSRs contributed to the development of novel markers. These data may serve as a new valuable resource for genomic studies on Youngia and, more generally, Cichoraceae.