p53 null Fluorescent Yellow Direct Repeat (FYDR) mice have normal levels of homologous recombination

The tumor suppressor p53 is a transcription factor whose function is critical for maintaining genomic stability in mammalian cells. In response to DNA damage, p53 initiates a signaling cascade that results in cell cycle arrest, DNA repair or, if the damage is severe, programmed cell death. In addition, p53 interacts with repair proteins involved in homologous recombination. Mitotic homologous recombination (HR) plays an essential role in the repair of double-strand breaks (DSBs) and broken replication forks. Loss of function of either p53 or HR leads to an increased risk of cancer. Given the importance of both p53 and HR in maintaining genomic integrity, we analyzed the effect of p53 on HR in vivo using Fluorescent Yellow Direct Repeat (FYDR) mice as well as with the sister chromatid exchange (SCE) assay. FYDR mice carry a direct repeat substrate in which an HR event can yield a fluorescent phenotype. Here, we show that p53 status does not significantly affect spontaneous HR in adult pancreatic cells in vivo or in primary fibroblasts in vitro when assessed using the FYDR substrate and SCEs. In addition, primary fibroblasts from p53 null mice do not show increased susceptibility to DNA damage-induced HR when challenged with mitomycin C. Taken together, the FYDR assay and SCE analysis indicate that, for some tissues and cell types, p53 status does not greatly impact HR.National Institute of Environmental Health Sciences (ES02109)National Cancer Institute (U.S.) (R33CA112151)National Cancer Institute (U.S.) (R01CA79827)United States. Dept. of Energy (DE-FG01-04ER04-21)National Institute of Environmental Health Sciences (T32 ES007020, NIEHS Training Grant in Environmental Toxicology)National Science Foundation (U.S.) (Fellowship

Enhanced immunoprecipitation techniques for the identification of RNA-binding protein partners: IGF2BP1 interactions in mammary epithelial cells

RNA-binding proteins (RBPs) regulate the expression of large cohorts of RNA species to produce programmatic changes in cellular phenotypes. To describe the function of RBPs within a cell, it is key to identify their mRNA-binding partners. This is often done by crosslinking nucleic acids to RBPs, followed by chemical release of the nucleic acid fragments for analysis. However, this methodology is lengthy, which involves complex processing with attendant sample losses, thus large amounts of starting materials and prone to artifacts. To evaluate potential alternative technologies, we tested exclusion-based purification of immunoprecipitates (IFAST or SLIDE) and report here that these methods can efficiently, rapidly, and specifically isolate RBP-RNA complexes. The analysis requires less than 1% of the starting material required for techniques that include crosslinking. Depending on the antibody used, 50% to 100% starting protein can be retrieved, facilitating the assay of endogenous levels of RBPs; the isolated ribonucleoproteins are subsequently analyzed using standard techniques, to provide a comprehensive portrait of RBP complexes. Using exclusion-based techniques, we show that the mRNA-binding partners for RBP IGF2BP1 in cultured mammary epithelial cells are enriched in mRNAs important for detoxifying superoxides (specifically glutathione peroxidase [GPX]-1 and GPX-2) and mRNAs encoding mitochondrial proteins. We show that these interactions are functionally significant, as loss of function of IGF2BP1 leads to destabilization of GPX mRNAs and reduces mitochondrial membrane potential and oxygen consumption. We speculate that this underlies a consistent requirement for IGF2BP1 for the expression of clonogenic activity in vitro

Research and Development as a Moderating Variable for Sustainable Economic Performance: The Asian, European, and Kuwaiti Models

The research and development (R&D) expenditure in Kuwait is insufficient to lead to innovation and a knowledge economy. Investment in R&D has been shown to sustain elevated economic performance. The objective of this study is to explore the association between three competing dimensions of R&D indicators that lead to sustainable economic performance within any given country, namely, R&D expenditure, the number of researchers, and the number of patent rights, using time-series data collected over a 20-year period (1996–2016) by the World Bank Group. R&D indicators were compared between high- and middle-income countries including models from Asian (South Korea, Singapore, and Malaysia) and European (Finland and Ireland) countries as well as the State of Kuwait. Moreover, a case study describing R&D investments in Kuwait is presented. Overall, the results reveal higher R&D spending, number of researchers, and gross domestic product (GDP) per capita for the Asian and European models. Current R&D expenditure in Kuwait is estimated at 0.08% of GDP (2016), which is significantly lower than the mean of the middle-income countries (1.58%). Furthermore, the number of researchers (per million) in Kuwait (386) is less than half of the mean number of researchers in middle-income countries (775) (2015). Low R&D investments in the State of Kuwait has gradually led to a decreased GDP per capita. Regression analysis shows that GDP per capita can be predicted solely based on the number of researchers (beta = 0.780, R2 = 0.608). The number of researchers is the most crucial variable to predict GDP per capita, and the R&D expenditure is a good indicator of the number of researchers. These findings offer invaluable insight into the sustainable development goals (SDG 9). To our knowledge, this paper presents the first application of the effect of R&D on sustainable economic performance with reference to the SDG target 9.5 “Research & Development”. Thus, in order to enhance scientific research (both academic, professional, and industrial), countries need to increase the number of researchers, and these actions are necessary to introduce sustainable growth to GDP

Genomic analysis of sewage from 101 countries reveals global landscape of antimicrobial resistance

Antimicrobial resistance (AMR) is a major threat to global health. Understanding the emergence, evolution, and transmission of individual antibiotic resistance genes (ARGs) is essential to develop sustainable strategies combatting this threat. Here, we use metagenomic sequencing to analyse ARGs in 757 sewage samples from 243 cities in 101 countries, collected from 2016 to 2019. We find regional patterns in resistomes, and these differ between subsets corresponding to drug classes and are partly driven by taxonomic variation. The genetic environments of 49 common ARGs are highly diverse, with most common ARGs carried by multiple distinct genomic contexts globally and sometimes on plasmids. Analysis of flanking sequence revealed ARG-specific patterns of dispersal limitation and global transmission. Our data furthermore suggest certain geographies are more prone to transmission events and should receive additional attention