832 research outputs found

    Dramatic expansion of the black widow toxin arsenal uncovered by multi-tissue transcriptomics and venom proteomics.

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    BackgroundAnimal venoms attract enormous interest given their potential for pharmacological discovery and understanding the evolution of natural chemistries. Next-generation transcriptomics and proteomics provide unparalleled, but underexploited, capabilities for venom characterization. We combined multi-tissue RNA-Seq with mass spectrometry and bioinformatic analyses to determine venom gland specific transcripts and venom proteins from the Western black widow spider (Latrodectus hesperus) and investigated their evolution.ResultsWe estimated expression of 97,217 L. hesperus transcripts in venom glands relative to silk and cephalothorax tissues. We identified 695 venom gland specific transcripts (VSTs), many of which BLAST and GO term analyses indicate may function as toxins or their delivery agents. ~38% of VSTs had BLAST hits, including latrotoxins, inhibitor cystine knot toxins, CRISPs, hyaluronidases, chitinase, and proteases, and 59% of VSTs had predicted protein domains. Latrotoxins are venom toxins that cause massive neurotransmitter release from vertebrate or invertebrate neurons. We discovered ≥ 20 divergent latrotoxin paralogs expressed in L. hesperus venom glands, significantly increasing this biomedically important family. Mass spectrometry of L. hesperus venom identified 49 proteins from VSTs, 24 of which BLAST to toxins. Phylogenetic analyses showed venom gland specific gene family expansions and shifts in tissue expression.ConclusionsQuantitative expression analyses comparing multiple tissues are necessary to identify venom gland specific transcripts. We present a black widow venom specific exome that uncovers a trove of diverse toxins and associated proteins, suggesting a dynamic evolutionary history. This justifies a reevaluation of the functional activities of black widow venom in light of its emerging complexity

    Report from the Cochairs

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    It has been a busy but exceedingly productive year for this CLAGS Board. Along with the creative series of public conferences, panels, and monthly colloquia mounted by the Program Committee, we have taken on the new challenges of a Fellowship Program generously funded by the Rockefeller Foundation, as well as cosponsorship of the Stonewall History Project. Indeed, as CLAGS continues to develop and expand, we are working overtime to keep up with our success

    Antiracist School Counselor Preparation: Expanding on the Five Tenets of the Transforming School Counseling Initiative

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    As a profession, school counseling must serve as an active force against systemic racism, and school counselor preparation must equip future professionals as antiracist agents of change. This article expands the original Transforming School Counseling Initiative (TSCI) tenets that sought to re-envision school counselor preparation in the late 1990s with language that explicitly supports antiracism. The authors offer a definition of antiracist school counseling and sample assignments and experiences that align with the revised tenets

    Evaluation of an Interprofessional Poverty Simulation Experience

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    Presented, 119th Annual Meeting of the American Association of Colleges of Pharmacy, Boston, Massachusetts, July 21-25, 2018Objectives: To evaluate the results of poverty simulation exercises when conducted as an interprofessional education (IPE) activity. Objectives were to determine if participating students demonstrated changes in 1) Attitude toward poverty and 2) Perceptions of interprofessional teamwork. Method: Two Missouri Association for Community Action Poverty Simulation exercises were conducted for an interprofessional student mix including Doctor of Pharmacy, Doctorate of Occupational Therapy, and Bachelor of Science in Nursing students. Students were randomly assigned to simulated family units with various life circumstances, while ensuring a mix of healthcare professional students per family. The families simulated typical daily living activities during 4 periods designated as weeks. Following the simulations, students participated in debriefing sessions to discuss their experience, including questions specific to interprofessionalism. Prior to and following the simulations, students completed two surveys: Attitude Toward Poverty Short Form (ATP-SF) and Refinement of the Interprofessional Socialization and Valuing Scale (ISVS-9). Paired-samples t-tests were used to determine the results. Results: Statistically significant improvements in attitude toward poverty were noted in 14 items on the 21-item ATP-SF. The domains of stigma and structural perspective showed statistically significant improvement while the personal deficiency domain did not. Statistically significant improvements in student perceptions related to interprofessional teamwork were not found using the ISVS-9 scale. Implications: An improved attitude toward poverty was measured for the domains of stigma and structural perspective following participation in a poverty simulation. An improvement in interprofessional teamwork was not found. The ISVS-9 may not have been an appropriate tool for this purpose

    Resistance to gemcitabine in a human follicular lymphoma cell line is due to partial deletion of the deoxycytidine kinase gene

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    BACKGROUND: Gemcitabine is an analogue of deoxycytidine with activity against several solid tumors. In order to elucidate the mechanisms by which tumor cells become resistant to gemcitabine, we developed the resistant subline RL-G from the human follicular lymphoma cell line RL-7 by prolonged exposure of parental cells to increasing concentrations of gemcitabine. RESULTS: In vitro, the IC(50 )increased from 0.015 μM in parental RL-7 cells to 25 μM in the resistant variant, RL-G. Xenografts of both cell lines developed in nude mice were treated with repeated injections of gemcitabine. Under conditions of gemcitabine treatment which totally inhibited the development of RL-7 tumors, RL-G derived tumors grew similarly to those of untreated animals, demonstrating the in vivo resistance of RL-G cells to gemcitabine. HPLC experiments showed that RL-G cells accumulated and incorporated less gemcitabine metabolites into DNA and RNA than RL-7 cells. Gemcitabine induced an S-phase arrest in RL-7 cells but not in RL-G cells. Exposure to gemcitabine induced a higher degree of apoptosis in RL-7 than in RL-G cells, with poly-(ADP-ribose) polymerase cleavage in RL-7 cells. No modifications of Bcl-2 nor of Bax expression were observed in RL-7 or RL-G cells exposed to gemcitabine. These alterations were associated with the absence of the deoxycytidine kinase mRNA expression observed by quantitative RT-PCR in RL-G cells. PCR amplification of désoxycytidine kinase gene exons showed a partial deletion of the dCK gene in RL-G cells. CONCLUSIONS: These results suggest that partial deletion of the dCK gene observed after selection in the presence of gemcitabine is involved with resistance to this agent both in vitro and in vivo

    Multi-tissue transcriptomics of the black widow spider reveals expansions, co-options, and functional processes of the silk gland gene toolkit

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    Background: Spiders (Order Araneae) are essential predators in every terrestrial ecosystem largely because they have evolved potent arsenals of silk and venom. Spider silks are high performance materials made almost entirely of proteins, and thus represent an ideal system for investigating genome level evolution of novel protein functions. However, genomic level resources remain limited for spiders. Results: We de novo assembled a transcriptome for the Western black widow (Latrodectus hesperus) from deeply sequenced cDNAs of three tissue types. Our multi-tissue assembly contained ~100,000 unique transcripts, of which > 27,000 were annotated by homology. Comparing transcript abundance among the different tissues, we identified 647 silk gland-specific transcripts, including the few known silk fiber components (e.g. six spider fibroins, spidroins). Silk gland specific transcripts are enriched compared to the entire transcriptome in several functions, including protein degradation, inhibition of protein degradation, and oxidation-reduction. Phylogenetic analyses of 37 gene families containing silk gland specific transcripts demonstrated novel gene expansions within silk glands, and multiple co-options of silk specific expression from paralogs expressed in other tissues. Conclusions: We propose a transcriptional program for the silk glands that involves regulating gland specific synthesis of silk fiber and glue components followed by protecting and processing these components into functional fibers and glues. Our black widow silk gland gene repertoire provides extensive expansion of resources for biomimetic applications of silk in industry and medicine. Furthermore, our multi-tissue transcriptome facilitates evolutionary analysis of arachnid genomes and adaptive protein systems. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-365) contains supplementary material, which is available to authorized users

    Climate Change and invasibility of the Antarctic benthos

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    Benthic communities living in shallow-shelf habitats in Antarctica (<100-m depth) are archaic in their structure and function. Modern predators, including fast-moving, durophagous (skeleton-crushing) bony fish, sharks, and crabs, are rare or absent; slow-moving invertebrates are the top predators; and epifaunal suspension feeders dominate many soft substratum communities. Cooling temperatures beginning in the late Eocene excluded durophagous predators, ultimately resulting in the endemic living fauna and its unique food-web structure. Although the Southern Ocean is oceanographically isolated, the barriers to biological invasion are primarily physiological rather than geographic. Cold temperatures impose limits to performance that exclude modern predators. Global warming is now removing those physiological barriers, and crabs are reinvading Antarctica. As sea temperatures continue to rise, the invasion of durophagous predators will modernize the shelf benthos and erode the indigenous character of marine life in Antarctica
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