Palytoxin Found in Palythoa sp. Zoanthids (Anthozoa, Hexacorallia) Sold in the Home Aquarium Trade

Zoanthids (Anthozoa, Hexacorallia) are colonial anemones that contain one of the deadliest toxins ever discovered, palytoxin (LD50 in mice 300 ng/kg), but it is generally believed that highly toxic species are not sold in the home aquarium trade. We previously showed that an unintentionally introduced zoanthid in a home aquarium contained high concentrations of palytoxin and was likely responsible for a severe respiratory reaction when an individual attempted to eliminate the contaminant colonies using boiling water. To assess the availability and potential exposure of palytoxin to marine aquarium hobbyists, we analyzed zoanthid samples collected from local aquarium stores for palytoxin using liquid chromatography and high resolution mass spectrometry and attempted to identify the specimens through genetic analysis of 16S and cytochrome c oxidase 1 (COI) markers. We found four specimens of the same apparent species of zoanthid, that we described previously to be responsible for a severe respiratory reaction in a home aquarium, to be available in three aquarium stores in the Washington D.C. area. We found all of these specimens (n = 4) to be highly toxic with palytoxin or palytoxin-like compounds (range 0.5–3.5 mg crude toxin/g zoanthid). One of the most potent non-protein compounds ever discovered is present in dangerous quantities in a select species of zoanthid commonly sold in the home aquarium trade

Screening the PRISM Library against Staphylococcus aureus Reveals a Sesquiterpene Lactone from Liriodendron tulipifera with Inhibitory Activity

Infections caused by the bacterium Staphylococcus aureus continue to pose threats to human health and put a financial burden on the healthcare system. The overuse of antibiotics has contributed to mutations leading to the emergence of methicillin-resistant S. aureus, and there is a critical need for the discovery and development of new antibiotics to evade drug-resistant bacteria. Medicinal plants have shown promise as sources of new small-molecule therapeutics with potential uses against pathogenic infections. The principal Rhode Island secondary metabolite (PRISM) library is a botanical extract library generated from specimens in the URI Youngken Medicinal Garden by upper-division undergraduate students. PRISM extracts were screened for activity against strains of methicillin-susceptible S. aureus (MSSA). An extract generated from the tulip tree (Liriodendron tulipifera) demonstrated growth inhibition against MSSA, and a bioassay-guided approach identified a sesquiterpene lactone, laurenobiolide, as the active constituent. Intriguingly, its isomers, tulipinolide and epi-tulipinolide, lacked potent activity against MSSA. Laurenobiolide also proved to be more potent against MSSA than the structurally similar sesquiterpene lactones, costunolide and dehydrocostus lactone. Laurenobiolide was the most abundant in the twig bark of the tulip tree, supporting the twig bark’s historical and cultural usage in poultices and teas

Controlling silver nanoparticle exposure in algal toxicity testing - A matter of timing

The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing. The freshwater green algae Pseudokirchneriella subcapitata were exposed to AgNO(3), NM-300 K (a representative AgNP) and citrate stabilized AgNPs from two different manufacturers (AgNP1 and AgNP2) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) (14)C-assimilation test. For AgNO(3), similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h test was found applicable for dissolved silver, but yielded non-monotonous concentration–response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration–response patterns emerged and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment AgNPs are added to the test medium. This time-dependency should be considered when nanomaterial dispersion protocols for ecotoxicity testing are developed

Tracking Changes in Bioavailable Fe Within High-Nitrate Low-Chlorophyll Oceanic Waters: A First Estimate Using a Heterotrophic Bacterial Bioreporter

It is conventional knowledge that heterotrophic bacteria play a key role in the biogeochemical cycling of oceanic carbon. However, only recently has their role in marine iron ( Fe) biogeochemical cycles been examined. Research during this past decade has demonstrated an inextricable link between Fe chemistry and the biota, as \u3e99% of Fe in marine systems is complexed to organic chelates of unknown but obviously biotic origin. Here we present a novel approach to assess and compare Fe bioavailability in low Fe HNLC waters using a bioluminescent bacterial reporter that quantitatively responds to the concentration of bioavailable Fe by producing light. Originally tested in freshwater environments, this study presents the first characterization of this halotolerant reporter organism in a defined seawater medium and then subsequently in marine surface waters. Laboratory characterizations demonstrate that this reporter displays a dose-dependent response to Fe availability in our defined marine medium. Field tests were performed during the 10-day mesoscale FeCycle experiment ( February 2003) in the Pacific sub-Antarctic high-nitrate low-chlorophyll region. Data from both biogeochemical measures and bioreporter assays are provided which describe how the bioreporter detected changes in Fe bioavailability that occurred during a natural shift in ambient dissolved Fe concentrations (similar to 40 pM). Our data explore the use of heterotrophic bioluminescent reporters as a comparable tool for marine ecosystems and demonstrate the potential utility of this tool in elucidating the relationship between Fe bioavailability and Fe chemistry in complex marine systems

Physiological Correlates of Volunteering

We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

Utilizing Big Data to Identify Tiny Toxic Components: Digitalis

The botanical genus Digitalis is equal parts colorful, toxic, and medicinal, and its bioactive compounds have a long history of therapeutic use. However, with an extremely narrow therapeutic range, even trace amounts of Digitalis can cause adverse effects. Using chemical methods, the United States Food and Drug Administration traced a 1997 case of Digitalis toxicity to a shipment of Plantago (a common ingredient in dietary supplements marketed to improve digestion) contaminated with Digitalis lanata. With increased accessibility to next generation sequencing technology, here we ask whether this case could have been cracked rapidly using shallow genome sequencing strategies (e.g., genome skims). Using a modified implementation of the Site Identification from Short Read Sequences (SISRS) bioinformatics pipeline with whole-genome sequence data, we generated over 2 M genus-level single nucleotide polymorphisms in addition to species-informative single nucleotide polymorphisms. We simulated dietary supplement contamination by spiking low quantities (0–10%) of Digitalis whole-genome sequence data into a background of commonly used ingredients in products marketed for “digestive cleansing” and reliably detected Digitalis at the genus level while also discriminating between Digitalis species. This work serves as a roadmap for the development of novel DNA-based assays to quickly and reliably detect the presence of toxic species such as Digitalis in food products or dietary supplements using genomic methods and highlights the power of harnessing the entire genome to identify botanical species

A DNA Mini-Barcoding System for Authentication of Processed Fish Products

Species substitution is a form of seafood fraud for the purpose of economic gain. DNA barcoding utilizes species-specific DNA sequence information for specimen identification. Previous work has established the usability of short DNA sequences—mini-barcodes—for identification of specimens harboring degraded DNA. This study aims at establishing a DNA mini-barcoding system for all fish species commonly used in processed fish products in North America. Six mini-barcode primer pairs targeting short (127–314 bp) fragments of the cytochrome c oxidase I (CO1) DNA barcode region were developed by examining over 8,000 DNA barcodes from species in the U.S. Food and Drug Administration (FDA) Seafood List. The mini-barcode primer pairs were then tested against 44 processed fish products representing a range of species and product types. Of the 44 products, 41 (93.2%) could be identified at the species or genus level. The greatest mini-barcoding success rate found with an individual primer pair was 88.6% compared to 20.5% success rate achieved by the full-length DNA barcode primers. Overall, this study presents a mini-barcoding system that can be used to identify a wide range of fish species in commercial products and may be utilized in high throughput DNA sequencing for authentication of heavily processed fish products

Fish Hybridization Leads to Uncertainty Regarding Ciguatera Fish Poisoning Risk; Confirmation of Hybridization and Ciguatoxin Accumulation with Implications for Stakeholders

Globally, ciguatera fish poisoning (CFP) avoidance efforts rely primarily on local knowledge of the fish being consumed, its collection location, and association with illnesses. In 2016, several fish that appeared to be hybrids between a local commercially prized species, Ocyurus chrysurus, and a regionally prohibited species Lutjanus apodus (due to CFP concerns), were caught nearshore in United States Virgin Islands waters, leading to confusion regarding the safety of consuming the fish. The hybrid status of the fish was verified as O. chrysurus (male) x L. apodus (female) by comparing two sets of gene sequences (mitochondrial CO1 and nuclear S7). Using an in vitro mouse neuroblastoma (N2a) assay, one of the hybrid fish exhibited a composite cytotoxicity of 0.038 ppb Caribbean ciguatoxin-1 (C-CTX-1) equivalents (Eq.); a concentration below the US Food and Drug Administration (FDA) guidance level for safety in fish products for CFP (0.1 ppb C-CTX-1 Eq.) but approximately 2x above the maximum described in the commercially prized parent species (0.019 ppb C-CTX-1 Eq./g). C-CTX-1 was confirmed in the hybrid sample by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The second hybrid fish tested negative for CTXs. This research confirms hybridization between two species with contrasting commercial statuses, discusses CTX accumulation implications for hybridization, and provides a methodology for future studies into novel CFP vectors, with the goal of providing critical information for fishermen and consumers regarding CFP risk management

Molecular phylogeny of ocelloid-bearing dinoflagellates (Warnowiaceae) as inferred from SSU and LSU rDNA sequences

Background: Dinoflagellates represent a major lineage of unicellular eukaryotes with unparalleled diversity and complexity in morphological features. The monophyly of dinoflagellates has been convincingly demonstrated, but the interrelationships among dinoflagellate lineages still remain largely unresolved. Warnowiid dinoflagellates are among the most remarkable eukaryotes known because of their possession of highly elaborate ultrastructural systems: pistons, nematocysts, and ocelloids. Complex organelles like these are evolutionary innovations found only in a few athecate dinoflagellates. Moreover, the taxonomy of warnowiids is extremely confusing and inferences about the evolutionary history of this lineage are mired by the absence of molecular phylogenetic data from any member of the group. In this study, we provide the first molecular phylogenetic data for warnowiids and couple them with a review of warnowiid morphological features in order to formulate a hypothetical framework for understanding character evolution within the group. These data also enabled us to evaluate the evolutionary relationship(s) between warnowiids and the other group of dinoflagellates with complex organelles: polykrikoids. Results: Molecular phylogenetic analyses of SSU and LSU rDNA sequences demonstrated that warnowiids form a well-supported clade that falls within the more inclusive Gymnodinium sensu stricto clade. These data also confirmed that polykrikoids are members of the Gymnodinium sensu stricto clade as well; however, a specific sister relationship between the warnowiid clade and the polykrikoid clade was unresolved in all of our analyses. Nonetheless, the new DNA sequences from different isolates of warnowiids provided organismal anchors for several previously unidentified sequences derived from environmental DNA surveys of marine biodiversity. Conclusion: Comparative morphological data and molecular phylogenetic data demonstrate that the polykrikoid and the warnowiid clade are closely related to each other, but the precise branching order within the Gymnodinium sensu stricto clade remains unresolved. We regard the ocelloid as the best synapomorphy for warnowiids and infer that the most recent common ancestor of polykrikoids and warnowiids possessed both nematocysts and photosynthetic plastids that were subsequently lost during the early evolution of warnowiids. Our summary of species and genus concepts in warnowiids demonstrate that the systematics of this poorly understood group is highly problematic and a comprehensive revision is needed.Botany, Department ofScience, Faculty ofZoology, Department ofNon UBCReviewedFacult

Reference-free discovery of nuclear SNPs permits accurate, sensitive identification of Carya (hickory) species and hybrids

Premise: DNA-based species identification is critical when morphological identification is restricted, but DNA-based identification pipelines typically rely on the ability to compare homologous sequence data across species. Because many clades lack robust genomic resources, we present here a bioinformatics pipeline capable of generating genome-wide single-nucleotide polymorphism (SNP) data while circumventing the need for any reference genome or annotation data. Methods: Using the SISRS bioinformatics pipeline, we generated de novo ortholog data for the genus Carya, isolating sites where genetic variation was restricted to a single Carya species (i.e., species-informative SNPs). We leveraged these SNPs to identify both full-species and hybrid Carya specimens, even at very low sequencing depths. Results: We identified between 46,000 and 476,000 species-identifying SNPs for each of eight diploid Carya species, and all species identifications were concordant with the species of record. For all putative F1 hybrid specimens, both parental species were correctly identified in all cases, and more punctate patterns of introgression were detectable in more cryptic crosses. Discussion: Bioinformatics pipelines that use only short-read sequencing data provide vital new tools enabling rapid expansion of DNA identification assays for model and non-model clades alike