Directed differentiation of human hindbrain neuroepithelial stem cells recapitulates cerebellar granule neurogenesis.

Cerebellar granule neurons (CGNs) are the most abundant neurons in the human brain. Dysregulation of their development underlies movement disorders and medulloblastomas. It is suspected that these disorders arise in progenitor states of the CGN lineage, for which human models are lacking. Here, we have differentiated human hindbrain neuroepithelial stem (hbNES) cells to CGNs in vitro using soluble growth factors, recapitulating key progenitor states in the lineage. We show that hbNES cells are not lineage committed and retain rhombomere 1 regional identity. Upon differentiation, hbNES cells transit through a rhombic lip (RL) progenitor state at day 7, demonstrating human specific sub-ventricular cell identities. This RL state is followed by an ATOH1+ CGN progenitor state at day 14. By the end of a 56-day differentiation procedure, we obtain functional neurons expressing CGN markers GABAARα6 and vGLUT2. We show that sonic hedgehog promotes GABAergic lineage specification and CGN progenitor proliferation. Our work presents a new model with which to study development and diseases of the CGN lineage in a human context.

iPSC-derived healthy human astrocytes selectively load miRNAs targeting neuronal genes into extracellular vesicles.

Astrocytes are in constant communication with neurons during the establishment and maturation of functional networks in the developing brain. Astrocytes release extracellular vesicles (EVs) containing microRNA (miRNA) cargo that regulates transcript stability in recipient cells. Astrocyte released factors are thought to be involved in neurodevelopmental disorders. Healthy astrocytes partially rescue Rett Syndrome (RTT) neuron function. EVs isolated from stem cell progeny also correct aspects of RTT. EVs cross the blood-brain barrier (BBB) and their cargo is found in peripheral blood which may allow non-invasive detection of EV cargo as biomarkers produced by healthy astrocytes. Here we characterize miRNA cargo and sequence motifs in healthy human astrocyte derived EVs (ADEVs). First, human induced Pluripotent Stem Cells (iPSC) were differentiated into Neural Progenitor Cells (NPCs) and subsequently into astrocytes using a rapid differentiation protocol. iPSC derived astrocytes expressed specific markers, displayed intracellular calcium transients and secreted ADEVs. miRNAs were identified by RNA-Seq on astrocytes and ADEVs and target gene pathway analysis detected brain and immune related terms. The miRNA profile was consistent with astrocyte identity, and included approximately 80 miRNAs found in astrocytes that were relatively depleted in ADEVs suggestive of passive loading. About 120 miRNAs were relatively enriched in ADEVs and motif analysis discovered binding sites for RNA binding proteins FUS, SRSF7 and CELF5. miR-483-5p was the most significantly enriched in ADEVs. This miRNA regulates MECP2 expression in neurons and has been found differentially expressed in blood samples from RTT patients. Our results identify potential miRNA biomarkers selectively sorted into ADEVs and implicate RNA binding protein sequence dependent mechanisms for miRNA cargo loading.

A vertebrate Polycomb response element governs segmentation of the posterior hindbrain.

Chromatin remodeling by Polycomb group (PcG) and trithorax group (trxG) proteins regulates gene expression in all metazoans. Two major complexes, Polycomb repressive complexes 1 and 2 (PRC1 and PRC2), are thought to mediate PcG-dependent repression in flies and mammals. In Drosophila, PcG/trxG protein complexes are recruited by PcG/trxG response elements (PREs). However, it has been unclear how PcG/trxG are recruited in vertebrates. Here we have identified a vertebrate PRE, PRE-kr, that regulates expression of the mouse MafB/Kreisler gene. PRE-kr recruits PcG proteins in flies and mouse F9 cells and represses gene expression in a PcG/trxG-dependent manner. PRC1 and 2 bind to a minimal PRE-kr region, which can recruit stable PRC1 binding but only weak PRC2 binding when introduced ectopically, suggesting that PRC1 and 2 have different binding requirements. Thus, we provide evidence that similar to invertebrates, PREs act as entry sites for PcG/trxG chromatin remodeling in vertebrates.

Evaluating the seasonal efficacy of commonly used chemical treatments on Varroa destructor (Mesostigmata: Varroidae) population resurgence in honey bee colonies.

The purpose of this research was to determine how common chemical treatments influence Varroa destructor (Anderson and Trueman) population resurgence rates (defined as time posttreatment for mite populations to reach 3 mites/100 adult bees) in managed honey bee (Apis mellifera L.) colonies seasonally. We conducted 2 experiments that followed the same basic protocol to address this purpose. We established 6 treatment groups in Experiment 1 in the fall of 2014: untreated control, Apivar, Apistan, CheckMite+, ApiLifeVar, and Mite Away II applied to 10 colonies per treatment. In Experiment 2, we applied 8 chemical treatments to each of 4 seasonal (spring, summer, fall, and winter) cohorts of honey bee colonies to determine how mite populations are influenced by the treatments. The treatments/formulations tested were Apivar, Apistan, Apiguard, MAQS, CheckMite+, oxalic acid (dribble), oxalic acid (shop towels), and amitraz (shop towels soaked in Bovitraz). In Experiment 1, Apivar and Mite Away II were able to delay V. destructor resurgence for 2 and 6 months, respectively. In Experiment 2, Apiguard, MAQS, oxalic acid (dribble), and Bovitraz treatments were effective at delaying V. destructor resurgence for at least 2 months during winter and spring. Only the Bovitraz and MAQS treatments were effective at controlling V. destructor in the summer and fall. Of the 2 amitraz-based treatments, the off-label Bovitraz treatment was the only treatment to reduce V. destructor populations in every season. The data gathered through this study allow for the refinement of treatment recommendations for V. destructor, especially regarding the seasonal efficacy of each miticide and the temporal efficacy posttreatment.

The pluripotency factor Nanog regulates pericentromeric heterochromatin organization in mouse embryonic stem cells.

An open and decondensed chromatin organization is a defining property of pluripotency. Several epigenetic regulators have been implicated in maintaining an open chromatin organization, but how these processes are connected to the pluripotency network is unknown. Here, we identified a new role for the transcription factor NANOG as a key regulator connecting the pluripotency network with constitutive heterochromatin organization in mouse embryonic stem cells. Deletion of Nanog leads to chromatin compaction and the remodeling of heterochromatin domains. Forced expression of NANOG in epiblast stem cells is sufficient to decompact chromatin. NANOG associates with satellite repeats within heterochromatin domains, contributing to an architecture characterized by highly dispersed chromatin fibers, low levels of H3K9me3, and high major satellite transcription, and the strong transactivation domain of NANOG is required for this organization. The heterochromatin-associated protein SALL1 is a direct cofactor for NANOG, and loss of Sall1 recapitulates the Nanog-null phenotype, but the loss of Sall1 can be circumvented through direct recruitment of the NANOG transactivation domain to major satellites. These results establish a direct connection between the pluripotency network and chromatin organization and emphasize that maintaining an open heterochromatin architecture is a highly regulated process in embryonic stem cells.

Developing a method to rear Varroa destructor in vitro.

Varroa destructor is a significant mite pest of western honey bees (Apis mellifera). Developing a method to rear and maintain populations of V. destructor in vitro would provide year-round access to the mites, allowing scientists to study their biology, behavior, and control more rapidly. In this study, we determined the impact of various rearing parameters on V. destructor survival and reproduction in vitro. This was done by collecting V. destructor from colonies, placing them in gelatin capsules containing honey bee larvae, and manipulating the following conditions experimentally: rearing temperature, colony source of honey bee larva, behavioral/developmental stages of V. destructor and honey bee larva, and mite:bee larva ratio. Varroa destructor survival was significantly impacted by temperature, colony source of larvae and mite behavioral stage. In addition, V. destructor reproduction was significantly impacted by mite: larva ratio, larval developmental stage, colony source of larva, and temperature. The following conditions optimized mite survival and reproduction in vitro: using a 4:1 mite:larva ratio, beginning the study with late stage uncapped larvae, using mites collected from adult bees, maintaining the rearing temperature at 34.5° C, and screening larval colony source. Ultimately, this research can be used to improve V. destructor in vitro rearing programs.

miR-22-enriched breast cancer cells display repressed glycolytic metabolism, increased glycogen synthesis, and reduced survival in low glucose conditions.

BACKGROUND: Breast cancer (BC) is the second leading cause of cancer-related mortality among women. Beyond the established tumourigenic role of genetic mutations, metabolic reprogramming is another key cancer hallmark. Glucose metabolism in particular is known to be prominently altered in tumours, in order to support biomass accumulation and cancer cell survival. The tumor suppressor microRNA (miRNA) miR-22 has been previously associated with a plethora of BC phenotypes such as growth, invasion-metastasis, and regulation of metabolic phenotypes such as lipid and folate metabolism. In this study, we aimed to investigate the role of miR-22 in the regulation of glucose metabolism in BC cells. METHODS AND RESULTS: Here we examined how miR-22 affects glucose metabolism in the MCF-7 BC cells. We found that over-expression of miR-22 caused a reduced glycolytic rate in these cells. Moreover, the miRNA also rendered MCF-7 cells more sensitive to lower glucose levels. We next unbiasedly screened the transcript levels of 84 genes relevant to glucose metabolism using the Human Glucose RT2 Profiler PCR Array. Interestingly, the strongest effect identified by this screen was the upregulation of genes involved in glycogen synthesis and the repression of gene involved in glycogen catabolism. Examination of publicly available transcriptomic datasets confirmed the correlations between expression of miR-22 and these glycogen metabolism genes in BC cells. CONCLUSION: This study has generated evidence for a regulatory role of miR-22 in glucose and glycogen metabolism, expanding the involvement of this miRNA in BC metabolic reprogramming.

Report of amoebic disease in a colony of Western honey bees (Apis mellifera).

The amoeba Malpighamoeba mellificae is the etiologic agent of amoebic (amoeba) disease of Western honey bees (Apis mellifera). M. mellificae damages the Malpighian tubules, which is believed to weaken and kill the host bee. Here, the authors describe the detection of this organism in a honey bee colony in the Yukon Territory, Canada. The Malpighian tubules of 14% (7/50) of the adult worker bees were discolored dark brown. Fifteen bees screened using conventional polymerase chain reaction for the 18S gene of M. mellificae were positive for the pathogen. Histologically, the lumens of Malpighian tubules were packed with amoebae, causing dilation of the tubules and attenuation and loss of the tubular epithelium. This phylogenetic analysis places M. mellificae in a new clade, a sister group to the Entamoebidae. This work provides a foundation for further investigation into the distribution, prevalence, and pathology associated with M. mellificae infection.

Widespread distribution of honey bee-associated pathogens in native bees and wasps: Trends in pathogen prevalence and co-occurrence.

Pollinators have experienced significant declines in the past decade, in part due to emerging infectious diseases. Historically, studies have primarily focused on pathogens in the Western honey bee, Apis mellifera. However, recent work has demonstrated that these pathogens are shared by other pollinators and can negatively affect their health. Here, we surveyed honey bees and 15 native bee and wasp species for 13 pathogens traditionally associated with honey bees. The native bee and wasp species included 11 species not previously screened for pathogens. We found at least one honey bee-associated pathogen in 53% of native bee and wasp samples. The most widely distributed and commonly detected pathogens were the microsporidian Nosema ceranae, the bacterium Melissococcus plutonius, and the viruses deformed wing virus and black queen cell virus. The prevalence of viruses was generally higher in honey bees than in native bees and wasps. However, the prevalence of M. plutonius and the brood fungus Ascosphaera apis was significantly higher in some native bee species than in honey bees. The data also reveal novel trends in the association between co-occurring pathogens in honey bees and native bees and wasps at the pathogen community level. These results can inform the assessment of risks that native pollinator species face from pathogen stress, and indicate that many non-viral pathogens, notably M. plutonius and N. ceranae, are far more widely distributed and commonly found in native bees and wasps than previously thought.

Oxalic acid application method and treatment intervals for reduction of Varroa destructor (Mesostigmata: Varroidae) populations in Apis mellifera (Hymenoptera: Apidae) colonies.

Oxalic acid (OA) is a popular miticide used to control Varroa destructor (Mesostigmata: Varroidae) in western honey bee (Apis mellifera L.) (Hymenoptera: Apidae) colonies. Our aim was to investigate which method of OA application (dribbling, fogging, or vaporizing) was the most effective at reducing V. destructor infestations (Experiment 1) and to improve upon this method by determining the treatment interval that resulted in the greatest V. destructor control (Experiment 2). We used the product Api-Bioxal (97% OA) and maintained 40 honey bee colonies (10/treatment) in both experiments. In Experiment 1, the treatments included (i) dribbling 50 ml of 3% OA solution, (ii) vaporizing 4 g of solid OA, (iii) using an insect fogger supplied with 2.5% OA dissolved in ethyl alcohol, and (iv) an untreated control. After 3 weeks, only the vaporization method reduced V. destructor infestations (from 9.24 mites/100 bees pretreatment to 3.25 mites/100 bees posttreatment) and resulted in significantly increased brood amounts and numbers of adult bees over those of the controls. In Experiment 2, all colonies were treated with 4 applications of OA via vaporization at a constant concentration of 4 g OA/colony. In this experiment, the groups were separated by treatment intervals at either 3-, 5-, or 7-day intervals. We observed that 5- and 7-day treatment intervals significantly reduced V. destructor populations from pretreatment levels over that of the controls and 3-day intervals. Our data demonstrate the efficacy of OA in reducing V. destructor infestation, particularly vaporizing 4 g every 5-7 days as the most effective method of application.

Regulation, diversity and function of MECP2 exon and 3'UTR isoforms.

The methyl-CpG-binding protein 2 (MECP2) is a critical global regulator of gene expression. Mutations in MECP2 cause neurodevelopmental disorders including Rett syndrome (RTT). MECP2 exon 2 is spliced into two alternative messenger ribonucleic acid (mRNA) isoforms encoding MECP2-E1 or MECP2-E2 protein isoforms that differ in their N-termini. MECP2-E2, isolated first, was used to define the general roles of MECP2 in methyl-deoxyribonucleic acid (DNA) binding, targeting of transcriptional regulatory complexes, and its disease-causing impact in RTT. It was later found that MECP2-E1 is the most abundant isoform in the brain and its exon 1 is also mutated in RTT. MECP2 transcripts undergo alternative polyadenylation generating mRNAs with four possible 3'untranslated region (UTR) lengths ranging from 130 to 8600 nt. Together, the exon and 3'UTR isoforms display remarkable abundance disparity across cell types and tissues during development. These findings indicate discrete means of regulation and suggest that protein isoforms perform non-overlapping roles. Multiple regulatory programs have been explored to explain these disparities. DNA methylation patterns of the MECP2 promoter and first intron impact MECP2-E1 and E2 isoform levels. Networks of microRNAs and RNA-binding proteins also post-transcriptionally regulate the stability and translation efficiency of MECP2 3'UTR isoforms. Finally, distinctions in biophysical properties in the N-termini between MECP2-E1 and E2 lead to variable protein stabilities and DNA binding dynamics. This review describes the steps taken from the discovery of MECP2, the description of its key functions, and its association with RTT, to the emergence of evidence revealing how MECP2 isoforms are differentially regulated at the transcriptional, post-transcriptional and post-translational levels.

Real-Time Monitoring of Gas-Phase and Dissolved CO2 Using a Mixed-Matrix Composite Integrated Fiber Optic Sensor for Carbon Storage Application.

Novel chemical sensors that improve detection and quantification of CO2 are critical to ensuring safe and cost-effective monitoring of carbon storage sites. Fiber optic (FO)-based chemical sensor systems are promising field-deployable systems for real-time monitoring of CO2 in geological formations for long-range distributed sensing. In this work, a mixed-matrix composite integrated FO sensor system was developed with a purely optical readout that reliably operates as a detector for gas-phase and dissolved CO2. A mixed-matrix composite sensor coating consisting of plasmonic nanocrystals and hydrophobic zeolite embedded in a polymer matrix was integrated on the FO sensor. The mixed-matrix composite FO sensor showed excellent reversibility/stability in a high humidity environment and sensitivity to gas-phase CO2 over a large concentration range. This remarkable sensing performance was enabled by using plasmonic nanocrystals to significantly enhance the sensitivity and a hydrophobic zeolite to effectively mitigate interference from water vapor. The sensor exhibited the ability to sense CO2 in the presence of other geologically relevant gases, which is of importance for applications in geological formations. A prototype FO sensor configuration, which possesses a robust sensing capability for monitoring dissolved CO2 in natural water, was demonstrated. Reproducibility was confirmed over many cycles, both in a laboratory setting and in the field. More importantly, we demonstrated on-line monitoring capabilities with a wireless telemetry system, which transferred the data from the field to a website. The combination of outstanding CO2 sensing properties and facile coating processability makes this mixed-matrix composite FO sensor a good candidate for practical carbon storage applications.

Cataract surgery and intraocular lens placement in patients with Fuchs corneal dystrophy: a review of the current literature.

PURPOSE OF REVIEW: Late-onset Fuchs endothelial corneal dystrophy (FECD) is seen in approximately 4% of individuals over the age of 40. With the growing population of adults over the age of 65, ophthalmologists need to be aware of the preoperative, perioperative, and postoperative considerations involved in cataract surgery in Fuchs patients. RECENT FINDINGS: Management of cataract patients with FECD requires preoperative assessment of endothelial cell size, density, and morphology. Considerations for perioperative endothelial cell loss include patients with hyperopia and shallow anterior chambers, phacoemulsification technique, transfer of ultrasonic energy to the cornea, corneal-protective perioperative agents, as well as thermal and mechanical damage. SUMMARY: Ophthalmologists performing cataract surgery on patients with FECD must carefully consider the risks of endothelial cell loss during surgery and minimize the risk of corneal decompensation after surgery. Preoperative management should evaluate the severity of the FECD as well as individual factors such as cataract density, the health and thickness of the cornea, and the anterior chamber depth. Perioperative techniques, adjustments to biometry calculations, and intraocular lens (IOL) selection may help optimize visual outcomes and recovery time.

Varroa destructor feeds primarily on honey bee fat body tissue and not hemolymph.

The parasitic mite Varroa destructor is the greatest single driver of the global honey bee health decline. Better understanding of the association of this parasite and its host is critical to developing sustainable management practices. Our work shows that this parasite is not consuming hemolymph, as has been the accepted view, but damages host bees by consuming fat body, a tissue roughly analogous to the mammalian liver. Both hemolymph and fat body in honey bees were marked with fluorescent biostains. The fluorescence profile in the guts of mites allowed to feed on these bees was very different from that of the hemolymph of the host bee but consistently matched the fluorescence profile unique to the fat body. Via transmission electron microscopy, we observed externally digested fat body tissue in the wounds of parasitized bees. Mites in their reproductive phase were then fed a diet composed of one or both tissues. Mites fed hemolymph showed fitness metrics no different from the starved control. Mites fed fat body survived longer and produced more eggs than those fed hemolymph, suggesting that fat body is integral to their diet when feeding on brood as well. Collectively, these findings strongly suggest that Varroa are exploiting the fat body as their primary source of sustenance: a tissue integral to proper immune function, pesticide detoxification, overwinter survival, and several other essential processes in healthy bees. These findings underscore a need to revisit our understanding of this parasite and its impacts, both direct and indirect, on honey bee health.

A cost comparison between reusable flexible and disposable laryngoscopes.

OBJECTIVES: To compare the costs of disposable laryngoscopes to reusable scopes in outpatient and inpatient settings. METHODS: The total variable and fixed costs involved in flexible scope reprocessing were collected from two general otolaryngology clinics, a pediatric otolaryngology clinic, and a children's hospital. Variable costs of disposable materials and labor were collected from 65 scope reprocessing events to identify the cost of reprocessing. Fixed costs of scope maintenance, monitors, video towers, and storage equipment were collected from financial records. Fixed and variable costs were analyzed to identify the cost per scope event. The costs were then compared to a theoretical model where disposable scopes were used to meet the volume demands of each clinic and children's hospital setting. The model of disposable scopes was generated after obtaining volume costs specific to each setting from a disposable scope company. RESULTS: The average cost of a reusable scope model per scope event was $66.02 ± 4.49 at the three clinics and $130.66 at the children's hospital. The average cost of the disposable scope model per scope event was $152.55 ± 0.55 in the three clinics and $172.61 in the children's hospital. The cost differences were $86.53 ± 3.96 and $41.95 respectively. CONCLUSIONS: In an outpatient clinic, reusable scopes are less expensive than a disposable scope model. In children's hospital inpatient setting, the difference in costs between disposable and reusable scopes is lower. When considering other non-economic factors, disposable scopes may be a feasible option, especially in the children's hospital setting.

Piloting participatory action research: Community as intermediary to education pathways of Congolese refugee youth.

OBJECTIVES: This pilot participatory action research (PAR) is aimed at increasing educational opportunities for refugee youth by demystifying higher education and providing relevant information. The project also aims to develop empirical knowledge regarding refugee youth's life trajectories and barriers to higher education, which informs collective action to enhance educational policies and programs for refugee youth. METHOD: In collaboration with community and student organizations in a midwestern urban area of the United States, we organized a higher education pathway program for Congolese refugee youth and community leaders aspiring to pursue higher education. Seven individuals attended a 1-day program, with a workshop, campus tour, and meeting with university administrators, and participated, along with two others, in a life history calendar interview. This article analyzes the PAR processes and interviews with participants. RESULTS: In addition to individual-level factors such as limited knowledge about college, various structural-level factors (i.e., school policies, procedures) impede education of refugee youth. Our analysis highlights the community as a source of both support and responsibility for refugee youth. Results show the need to educate the community about higher education but also the need to educate the university about refugee education and the community's pivotal role in doing so. CONCLUSIONS: Our findings offer a three-level (individual, structural, and community) framework of education pathways for resettled refugees. A critical analysis of how factors at multiple levels interact and produce unique challenges and possibilities furthers the field of refugee studies and also informs more holistic, sustainable policies and programs for refugee education. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Coding regions affect mRNA stability in human cells.

A new paradigm has emerged that coding regions can regulate mRNA stability in model organisms. Here, due to differences in cognate tRNA abundance, synonymous codons are translated at different speeds, and slow codons then stimulate mRNA decay. To ask if this phenomenon also occurs in humans, we isolated RNA stability effects due to coding regions using the human ORFeome collection. We find that many open reading frame (ORF) characteristics, such as length and secondary structure, fail to provide explanations for how coding regions alter mRNA stability, and, instead, that the ORF relies on translation to impact mRNA stability. Consistent with what has been seen in other organisms, codon use is related to the effects of ORFs on transcript stability. Importantly, we found instability-associated codons have longer A-site dwell times, suggesting for the first time in humans a connection between elongation speed and mRNA decay. Thus, we propose that codon usage alters decoding speeds and so affects human mRNA stability.

Everolimus Rescues the Phenotype of Elastin Insufficiency in Patient Induced Pluripotent Stem Cell-Derived Vascular Smooth Muscle Cells.

OBJECTIVE: Elastin gene deletion or mutation leads to arterial stenoses due to vascular smooth muscle cell (SMC) proliferation. Human induced pluripotent stem cells-derived SMCs can model the elastin insufficiency phenotype in vitro but show only partial rescue with rapamycin. Our objective was to identify drug candidates with superior efficacy in rescuing the SMC phenotype in elastin insufficiency patients. Approach and Results: SMCs generated from induced pluripotent stem cells from 5 elastin insufficiency patients with severe recurrent vascular stenoses (3 Williams syndrome and 2 elastin mutations) were phenotypically immature, hyperproliferative, poorly responsive to endothelin, and exerted reduced tension in 3-dimensional smooth muscle biowires. Elastin mRNA and protein were reduced in SMCs from patients compared to healthy control SMCs. Fourteen drug candidates were tested on patient SMCs. Of the mammalian target of rapamycin inhibitors studied, everolimus restored differentiation, rescued proliferation, and improved endothelin-induced calcium flux in all patient SMCs except one Williams syndrome. Of the calcium channel blockers, verapamil increased SMC differentiation and reduced proliferation in Williams syndrome patient cells but not in elastin mutation patients and had no effect on endothelin response. Combination treatment with everolimus and verapamil was not superior to everolimus alone. Other drug candidates had limited efficacy. CONCLUSIONS: Everolimus caused the most consistent improvement in SMC differentiation, proliferation and in SMC function in patients with both syndromic and nonsyndromic elastin insufficiency, and offers the best candidate for drug repurposing for treatment of elastin insufficiency associated vasculopathy.

Identification of TIA1 mRNA targets during human neuronal development.

BACKGROUND: Neuronal development is a tightly controlled process involving multi-layered regulatory mechanisms. While transcriptional pathways regulating neurodevelopment are well characterized, post-transcriptional programs are still poorly understood. TIA1 is an RNA-binding protein that can regulate splicing, stability, or translation of target mRNAs, and has been shown to play critical roles in stress response and neurodevelopment. However, the identity of mRNAs regulated by TIA1 during neurodevelopment under unstressed conditions is still unknown. METHODS AND RESULTS: To identify the mRNAs targeted by TIA1 during the first stages of human neurodevelopment, we performed RNA immunoprecipitation-sequencing (RIP-seq) on human embryonic stem cells (hESCs) and derived neural progenitor cells (NPCs), and cortical neurons under unstressed conditions. While there was no change in TIA1 protein levels, the number of TIA1 targeted mRNAs decreased from pluripotent cells to neurons. We identified 2400, 845, and 330 TIA1 mRNA targets in hESCs, NPC, and neurons, respectively. The vast majority of mRNA targets in hESC were genes associated with neurodevelopment and included autism spectrum disorder-risk genes that were not bound in neurons. Additionally, we found that most TIA1 mRNA targets have reduced ribosomal engagement levels. CONCLUSION: Our results reveal TIA1 mRNA targets in hESCs and during human neurodevelopment, indicate that translation repression is a key process targeted by TIA1 binding and implicate TIA1 function in neuronal differentiation.

Mitigating Nosema ceranae infection in western honey bee (Apis mellifera) workers using propolis collected from honey bee and stingless bee (Tetrigona apicalis) hives.

Beekeepers need sustainable control options to treat Nosema ceranae infection in colonies of western honey bees (Apis mellifera L.) they manage. Propolis is a natural product derived from plant resins and contains chemical compounds with potential antimicrobial activity against N. ceranae. Here, we determined the efficacy of propolis from A. mellifera (USA) and Tetrigona apicalis (stingless bees, Thailand) colonies as treatments for N. ceranae infection in honey bee workers. Newly emerged bees were individually fed 2 µL of 50% (w/v) sucrose solution containing 1 × 105N. ceranae spores. Following this, the infected bees were treated with 50% propolis extracted from A. mellifera or T. apicalis hives and fed in 50% sucrose solution (v/v). All bees were maintained at 34 ± 2 °C and 55 ± 5% RH. Dead bees were counted daily for 30 d to calculate survival. We also determined infection rate (# infected bees/100 bees), infectivity (number of spores per bee) and protein content in the hypopharyngeal glands and hemolymph on 7, 14, and 21 d post infection as measures of bee health. Propolis from both bee species significantly reduced bee mortality, infection rate and infectivity compared with those of untreated bees and led to significantly greater protein contents in hypopharyngeal glands and hemolymph in treated bees than in untreated ones (p < 0.0001). In conclusion, propolis from A. mellifera and T. apicalis colonies shows promise as a control against N. ceranae infection in honey bees.