Ara h 6 Complements Ara h 2 as an Important Marker for IgE Reactivity to Peanut

The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. SDS-PAGE of the highly purified allergen (\u3c0.01% Ara h 2) revealed a single 14.5kD band and the identity of Ara h 6 was confirmed by LC-MS/MS. Ara h 6 showed a higher seroprevalence in chimeric-IgE ELISA (n=54), but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays, as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy

Ara h 6 Complements Ara h 2 as an Important Marker for IgE Reactivity to Peanut

The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. SDS-PAGE of the highly purified allergen (\u3c0.01% Ara h 2) revealed a single 14.5kD band and the identity of Ara h 6 was confirmed by LC-MS/MS. Ara h 6 showed a higher seroprevalence in chimeric-IgE ELISA (n=54), but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays, as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy

Changes in gene expression of Prymnesium parvum due to nitrogen and phosphorus limitation.

Prymnesium parvum is a globally distributed prymnesiophyte alga commonly found in brackish water marine ecosystems and lakes. It possesses a suite of toxins with ichthyotoxic, cytotoxic and hemolytic effects which, along with its mixotrophic nutritional capabilities, allows it to form massive Ecosystem Disruptive Algal Blooms (EDABs). While blooms of high abundance coincide with high levels of nitrogen (N) and phosphorus (P), reports of field and laboratory studies have noted that P. parvum toxicity appears to be augmented at high N:P ratios or P-limiting conditions. Here we present the results of a comparative analysis of P. parvum RNA-Seq transcriptomes under nutrient replete conditions, and N or P deficiency to understand how this organism responds at the transcriptional level to varying nutrient conditions. In nutrient limited conditions we found diverse transcriptional responses for genes involved in nutrient uptake, protein synthesis and degradation, photosynthesis, and toxin production. As anticipated, when either N or P was limiting, transcription levels of genes encoding transporters for the respective nutrient were higher than those under replete condition. Ribosomal and lysosomal protein genes were expressed at higher levels under either nutrient-limited condition compared to the replete condition. Photosynthesis genes and polyketide synthase genes were more highly expressed under P-limitation but not under N-limitation. These results highlight the ability of P. parvum to mount a coordinated and varied cellular and physiological response to nutrient limitation. Results also provide potential marker genes for further evaluating the physiological response and toxin production of P. parvum populations during bloom formation or to changing environmental conditions

Comparative Transcriptome Analysis of Four Prymnesiophyte Algae

<div><p>Genomic studies of bacteria, archaea and viruses have provided insights into the microbial world by unveiling potential functional capabilities and molecular pathways. However, the rate of discovery has been slower among microbial eukaryotes, whose genomes are larger and more complex. Transcriptomic approaches provide a cost-effective alternative for examining genetic potential and physiological responses of microbial eukaryotes to environmental stimuli. In this study, we generated and compared the transcriptomes of four globally-distributed, bloom-forming prymnesiophyte algae: <i>Prymnesium parvum</i>, <i>Chrysochromulina brevifilum</i>, <i>Chrysochromulina ericina</i> and <i>Phaeocystis antarctica</i>. Our results revealed that the four transcriptomes possess a set of core genes that are similar in number and shared across all four organisms. The functional classifications of these core genes using the euKaryotic Orthologous Genes (KOG) database were also similar among the four study organisms. More broadly, when the frequencies of different cellular and physiological functions were compared with other protists, the species clustered by both phylogeny and nutritional modes. Thus, these clustering patterns provide insight into genomic factors relating to both evolutionary relationships as well as trophic ecology. This paper provides a novel comparative analysis of the transcriptomes of ecologically important and closely related prymnesiophyte protists and advances an emerging field of study that uses transcriptomics to reveal ecology and function in protists.</p></div

Polyketide synthase maximum likelihood tree with 100 iterated bootstraps using only the keto-synthase (KS) domain.

<p>The tree was inferred using MEGA5 (Tamura et al. 2011) with maximum likelihood method based on Jones-Taylor-Thornton model. The analysis involved 78 amino acid sequences. All positions with less than 95% site coverage were eliminated. There were 181 total sites in the final dataset. Bootstrap support values, if greater than 50%, are shown as the percentages of 100 trees inferred in the analysis. The scale bar represents the number of substitutions per site. The tree is rooted with <i>Aspergillus nidulans</i> polyketide synthase. Sequences from our dataset are shown in bold. Multiple branches have the same identifying ORFs,GI or accession numbers due to multiple KS domains on the same gene.</p

Core, shared and unique transcriptome genes in four prymnesiophyte species: <i>Prymnesium parvum</i>, <i>Chrysochromulina brevifilum</i>, <i>Chrysochromulina ericina and Phaeocystis antarctica</i>.

<p>A) Venn diagram showing the number of shared or unique genes (in italics) and gene clusters (in bold) among the four prymnesiophytes as classified by the orthomcl program. Among the genes unique to each of the four prymnesiophytes, multi-copy genes refer to genes that were present in gene clusters, single-copy genes refer to genes that did not cluster with any other gene. Pp: <i>Prymnesium parvum</i>, Cb: <i>Chrysochromulina brevifilum</i>, Ce: <i>Chrysochromulina ericina</i>, Pa: <i>Phaeocystis antarctica</i>. B) Proportion of annotated and unannotated genes in the “core” gene set, <i>i.e.</i> genes shared by all four species, and in the gene set unique to each species. C) Proportion of the transcripts that comprised core, shared and unique genes. Shared genes are genes present in two or three of the four species. Unique genes are genes that are only present in one species.</p

Principal component analysis (PCA) plot of the KOG distributions of the four prymnesiophytes in this study and of other protistan genomes and transcriptomes.

<p>The same dataset from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0097801#pone-0097801-g005" target="_blank">Fig. 5</a> was used to generate this figure. The color scheme and species identification by numbering also correspond to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0097801#pone-0097801-g005" target="_blank">Fig. 5</a>. Explained cumulative variability for this plot was 54.2%, with eigenvalues of 8.5 (F1) and 4.5 (F2). Only top variables for F1 and F2 are plotted in the graph.</p

Basic statistics for the four transcriptomes sequenced in this study.

<p>Basic statistics for the four transcriptomes sequenced in this study.</p

KOG function distribution of the peptides for the four target species in this study.

<p>The KOG functions are as follows: A: RNA processing and modification; B: chromatin structure and dynamics; C: Energy production and conversion; D: Cell cycle control, cell division, chromosome partitioning; E: Amino acid transport and metabolism; F: Nucleotide transport and metabolism; G: Carbohydrate transport and metabolism; H: Coenzyme transport and metabolism; I: Lipid transport and metabolism; J: Translation, ribosomal structure and biogenesis; K: Transcription; L: Replication, recombination and repair; M: Cell wall/membrane/envelope biogenesis; N: Cell motility; O: Posttranslational modification, protein turnover, chaperones; P: Inorganic ion transport and metabolism; Q: Secondary metabolites biosynthesis, transport and catabolism; R: General function prediction only; S: Function unknown; T: Signal transduction mechanisms; U: Intracellular trafficking, secretion and vesicular transport; V: Defense mechanisms; W: Extracellular structures; Y: Nuclear structure; Z: Cytoskeleton.</p