A retrospective analysis of honey bee (Apis mellifera) pesticide toxicity data.

Current USEPA ecological risk assessments for pesticide registration include a determination of potential risks to bees. Toxicity data are submitted to support these assessments and the USEPA maintains a large database containing acute and chronic toxicity data on adult and larval honey bees (Apis mellifera), which USEPA considers a surrogate for Apis and non-Apis bees. We compared these toxicity data to explore possible trends.

Drone honey bees are disproportionately sensitive to abiotic stressors despite expressing high levels of stress response proteins.

Drone honey bees (Apis mellifera) are the obligate sexual partners of queens, and the availability of healthy, high-quality drones directly affects a queen's fertility and productivity. Yet, our understanding of how stressors affect adult drone fertility, survival, and physiology is presently limited. Here, we investigated sex biases in susceptibility to abiotic stressors (cold stress, topical imidacloprid exposure, and topical exposure to a realistic cocktail of pesticides).

Honey bee queen health is unaffected by contact exposure to pesticides commonly found in beeswax.

Honey bee queen health is crucial for colony health and productivity, and pesticides have been previously associated with queen loss and premature supersedure. Prior research has investigated the effects of indirect pesticide exposure on queens via workers, as well as direct effects on queens during development. However, as adults, queens are in constant contact with wax as they walk on comb and lay eggs; therefore, direct pesticide contact with adult queens is a relevant but seldom investigated exposure route.

Effects of developmental exposure to pesticides in wax and pollen on honey bee (Apis mellifera) queen reproductive phenotypes.

Stressful conditions during development can have sub-lethal consequences on organisms aside from mortality. Using previously reported in-hive residues from commercial colonies, we examined how multi-pesticide exposure can influence honey bee (Apis mellifera) queen health. We reared queens in beeswax cups with or without a pesticide treatment within colonies exposed to treated or untreated pollen supplement.

Colony-level pesticide exposure affects honey bee (Apis mellifera L.) royal jelly production and nutritional composition.

Honey bees provision glandular secretions in the form of royal jelly as larval nourishment to developing queens. Exposure to chemicals and nutritional conditions can influence queen development and thus impact colony fitness. Previous research reports that royal jelly remains pesticide-free during colony-level exposure and that chemical residues are buffered by the nurse bees.

Differences in larval pesticide tolerance and esterase activity across honey bee (Apis mellifera) stocks.

Honey bee populations in North America are an amalgamation of diverse progenitor ecotypes experiencing varying levels of artificial selection. Genetic differences between populations can result in variable susceptibility towards environmental stressors, and here we compared pesticide tolerances across breeding stocks using a mixture of seven pesticides frequently found in colonies providing pollination services. We administered the pesticide mixture chronically to in vitro reared larvae at four concentrations of increasing Hazard Quotient (HQ, or cumulative toxicity) and measured mortality during larval development.

Candidate stress biomarkers for queen failure diagnostics.

Background: Queen failure is a persistent problem in beekeeping operations, but in the absence of overt symptoms it is often difficult, if not impossible, to ascertain the root cause. Stressors like heat-shock, cold-shock, and sublethal pesticide exposure can reduce stored sperm viability and lead to cryptic queen failure. Previously, we suggested candidate protein markers indicating heat-shock in queens.

Continuing to strengthen FDA's science approach to emerging technologies.

Emerging technologies result when advances and innovation in technology lead to discoveries. Often emerging technologies stimulate novel research in medical product development that contribute to new approaches to manufacturing and can improve the quality of products. By supporting investments in agency coordination, staff training and professional development, regulatory science research, stakeholder engagement, and enhancing opportunities for expert input, the U.

PolyA-specific ribonuclease (PARN-1) function in stage-specific mRNA turnover in Trypanosoma brucei.

Deadenylation is often the rate-limiting event in regulating the turnover of cellular mRNAs in eukaryotes. Removal of the poly(A) tail initiates mRNA degradation by one of several decay pathways, including deadenylation-dependent decapping, followed by 5' to 3' exonuclease decay or 3' to 5' exosome-mediated decay. In trypanosomatids, mRNA degradation is important in controlling the expression of differentially expressed genes.

Characterization of deadenylation in trypanosome extracts and its inhibition by poly(A)-binding protein Pab1p.

The stability of mRNAs is an important point in the regulation of gene expression in eukaryotes. The mRNA turnover pathways have been identified in yeast and mammals. However, mRNA turnover pathways in trypanosomes have not been widely studied.

Assessing messenger RNA decapping in cellular extracts.

Removal of the 5' cap from a messenger RNA (mRNA) is an integral part of all mRNA decay pathways and can be a highly regulated event. Assays designed to assess decapping in vitro need to effectively resolve four products of mRNA decay: 7meGpppG produced by 3'-5' shortening of the transcript by the exosome, 7meGMP produced by the scavenger decapping enzyme DcpS acting on the product of exosomal decay, 7meGDP produced by the Dcp1/2 decapping enzyme, and free phosphate, which can be generated by phosphatases in the extract acting upon either of the two products of decapping noted above. We have outlined both thin-layer chromatography and acrylamide-gel based approaches that can be used to assess decapping activities.

Identification of mRNA decapping activities and an ARE-regulated 3' to 5' exonuclease activity in trypanosome extracts.

mRNA turnover is a regulated process that contributes to the steady state level of cytoplasmic mRNA. The amount of each mRNA determines, to a large extent, the amount of protein produced by that particular transcript. In trypanosomes, there is little transcriptional regulation; therefore, differential mRNA stability significantly contributes to mRNA levels in each stage of the parasite life cycle.