A translational repression complex in developing mammalian neural stem cells that regulates neuronal specification

The mechanisms instructing genesis of neuronal sub-types from mammalian neural precursors are not well understood. To address this issue, we have characterized the transcriptional landscape of radial glial precursors (RPs) in the embryonic murine cortex. We show that individual RPs express mRNA, but not protein , for transcriptional specifiers of both deep and superficial layer cortical neurons. Some of these mRNAs, including the superficial versus deep layer neuron transcriptional regulators Brn1 and Tle4, are translationally repressed by their association with the RNA-binding protein Pumilio2 (Pum2) and the 4E-T protein. Disruption of these repressive complexes in RPs mid-neurogenesis by knocking down 4E-T or Pum2 causes aberrant co-expression of deep layer neuron specification proteins in newborn superficial layer neurons. Thus, cortical RPs are transcriptionally primed to generate diverse types of neurons, and a Pum2/4E-T complex represses translation of some of these neuronal identity mRNAs to ensure appropriate temporal specification of daughter neurons.No sponso

Developmental Emergence of Adult Neural Stem Cells as Revealed by Single-Cell Transcriptional Profiling

Adult neural stem cells (NSCs) derive from embryonic precursors, but little is known about how or when this occurs. We have addressed this issue using single-cell RNA sequencing at multiple developmental time points to analyze the embryonic murine cortex, one source of adult forebrain NSCs. We computationally identify all major cortical cell types, including the embryonic radial precursors (RPs) that generate adult NSCs. We define the initial emergence of RPs from neuroepithelial stem cells at E11.5. We show that, by E13.5, RPs express a transcriptional identity that is maintained and reinforced throughout their transition to a non-proliferative state between E15.5 and E17.5. These slowly proliferating late embryonic RPs share a core transcriptional phenotype with quiescent adult forebrain NSCs. Together, these findings support a model wherein cortical RPs maintain a core transcriptional identity from embryogenesis through to adulthood and wherein the transition to a quiescent adult NSC occurs during late neurogenesis

Soil DNA chronosequence analysis shows bacterial community re‐assembly following post‐mining forest rehabilitation

Mining activities modify both aboveground and belowground ecological communities, presenting substantial challenges for restoration. The soil microbiome is one of these impacted communities and performs important ecosystem functions but receives limited focus in restoration. Sequencing soil DNA enables accurate and cost-effective assessment of soil microbiota, allowing for comparisons across land use, environmental, and temporal gradients. We used amplicon sequencing of the bacterial 16s rRNA gene extracted from soil samples across a 28-year post-mining rehabilitation chronosequence to assess soil bacterial composition and diversity following rehabilitation at a bauxite mine in Western Australia's jarrah forest. We show that while bacterial alpha diversity did not differ between reference and rehabilitated sites, bacterial community composition changed dramatically across the chronosequence, suggesting strong impacts by mining and rehabilitation activities. Bacterial communities generally became increasingly similar to unmined reference sites with time since rehabilitation. Soil from sites rehabilitated as recently as 14 years ago did not have significantly different communities to reference sites. Overall, our study provides evidence indicating the recovery of soil bacterial communities toward reference states following rehabilitation. Including several ecological reference sites revealed substantial natural variability in bacterial communities from within a single mine site. We urge future restoration chronosequence studies to sample reference sites that geographically span the restored sites and/or are spatially paired with restored sites to ensure this variability is captured and to improve any inferences on recovery

Advice on assistance and protection provided by the Scientific Advisory Board of the Organisation for the Prohibition of Chemical Weapons: Part 3. On medical care and treatment of injuries from sulfur mustard

Blister agents damage the skin, eyes, mucous membranes and subcutaneous tissues. Other toxic effects may occur after absorption. The response of the Scientific Advisory Board (SAB) of the Organisation for the Prohibition of Chemical Weapons (OPCW) to a request from the OPCW Director-General in 2013 on the status of medical countermeasures and treatments to blister agents is updated through the incorporation of the latest information. The physical and toxicological properties of sulfur mustard and clinical effects and treatments are summarised. The information should assist medics and emergency responders who may be unfamiliar with the toxidrome of sulfur mustard and its treatment.Fil: Timperley, Christopher M.. Defence Science And Technology Laboratory; Reino UnidoFil: Forman, Jonathan E.. Organisation For The Prohibition Of Chemical Weapons; Países BajosFil: Abdollahi, Mohammad. Tehran University of Medical Sciences; IránFil: Al-Amri, Abdullah Saeed. Saudi Basic Industries Corporation; Arabia SauditaFil: Baulig, Augustin. Secrétariat Général de la Défense Et de la Sécurité Nationale; FranciaFil: Benachour, Djafer. Ferhat Abbas University; ArgeliaFil: Borrett, Veronica. La Trobe University; AustraliaFil: Cariño, Flerida A.. University Of The Philippines Diliman; FilipinasFil: Curty, Christophe. Spiez Laboratory; SuizaFil: Geist, Michael. Basf Se; AlemaniaFil: Gonzalez, David. Universidad de la República; UruguayFil: Kane, William. Monsanto Company; Estados UnidosFil: Kovarik, Zrinka. Institut Za Medicinska Istrazivanja I Medicinu Rada; CroaciaFil: Martínez Álvarez, Roberto. Universidad Complutense de Madrid; EspañaFil: Mourão, Nicia Maria Fusaro. Brazilian Chemical Industry; BrasilFil: Neffe, Slawomir. Wojskowa Akademia Techniczna; PoloniaFil: Raza, Syed K.. National Accreditation Board For Testing And Calibration Laboratories; IndiaFil: Rubaylo, Valentin. State Research Institute Of Organic Chemistry And Technology; RusiaFil: Suarez, Alejandra Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Takeuchi, Koji. National Institute Of Advanced Industrial Science And Technology; JapónFil: Tang, Cheng. Ministry of National Defence. Office for the Disposal of Japanese Abandoned Chemical Weapons; ChinaFil: Trifirò, Ferruccio. Universidad de Bologna; ItaliaFil: Straten, Francois Mauritz van. Independent Former Opcw Sab Member; SudáfricaFil: Vanninen, Paula S.. University of Helsinki; FinlandiaFil: Vucinic, Slavica. Vojnomedicinska Akademija; SerbiaFil: Zaitsev, Volodymyr. Pontifícia Universidade Católica do Rio de Janeiro; BrasilFil: Zafar-Uz-Zaman, Muhammad. National Engineering And Scientific Commission; PakistánFil: Zina, Mongia Saïd. Université de Tunis El Manar, Faculté Des Sciences de Tunis; TúnezFil: Holen, Stian. OPCW; Países BajosFil: Alwan, Wesam S.. Monash University; AustraliaFil: Suri, Vivek. OPCW Office of Strategy and Policy; Países BajosFil: Hotchkiss, Peter J.. Organisation For The Prohibition Of Chemical Weapons; Países BajosFil: Ghanei, Mostafa. Baqiyatallah University Of Medical Sciences; Irá