Large experimental programmes in the fields of nuclear and particle physics search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson completed the set of particles predicted by the standard model, which currently provides the best description of fundamental particles and forces. However, this theory's limitations include a failure to predict fundamental parameters, such as the mass of the Higgs boson, and the inability to account for dark matter and energy, gravity, and the matter-antimatter asymmetry in the Universe, among other phenomena. These limitations have inspired searches for physics beyond the standard model in the post-Higgs era through the direct production of additional particles at high-energy accelerators, which have so far been unsuccessful. Examples include searches for supersymmetric particles, which connect bosons (integer-spin particles) with fermions (half-integer-spin particles), and for leptoquarks, which mix the fundamental quarks with leptons. Alternatively, indirect searches using precise measurements of well predicted standard-model observables allow highly targeted alternative tests for physics beyond the standard model because they can reach mass and energy scales beyond those directly accessible by today's high-energy accelerators. Such an indirect search aims to determine the weak charge of the proton, which defines the strength of the proton's interaction with other particles via the well known neutral electroweak force. Because parity symmetry (invariance under the spatial inversion (x, y, z) → (-x, -y, -z)) is violated only in the weak interaction, it provides a tool with which to isolate the weak interaction and thus to measure the proton's weak charge . Here we report the value 0.0719 ± 0.0045, where the uncertainty is one standard deviation, derived from our measured parity-violating asymmetry in the scattering of polarized electrons on protons, which is -226.5 ± 9.3 parts per billion (the uncertainty is one standard deviation). Our value for the proton's weak charge is in excellent agreement with the standard model and sets multi-teraelectronvolt-scale constraints on any semi-leptonic parity-violating physics not described within the standard model. Our results show that precision parity-violating measurements enable searches for physics beyond the standard model that can compete with direct searches at high-energy accelerators and, together with astronomical observations, can provide fertile approaches to probing higher mass scales.
Many studies have been conducted to improve economically important livestock traits such as feed efficiency and muscle growth. Genome editing technologies represent a major advancement for both basic research and agronomic biotechnology development. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technical platform is a powerful tool used to engineer specific targeted loci. However, the potential occurrence of off‐target effects, including the cleavage of unintended targets, limits the practical applications of Cas9‐mediated genome editing. In this study, to minimize the off‐target effects of this technology, we utilized D10A‐Cas9 nickase to generate myostatin‐knockout (MSTN KO) chickens via primordial germ cells. D10A‐Cas9 nickase (Cas9n)‐mediated MSTN KO chickens exhibited significantly larger skeletal muscles in the breast and leg. Degrees of skeletal muscle hypertrophy and hyperplasia induced by myostatin deletion differed by sex and muscle type. The abdominal fat deposition was dramatically lower in MSTN KO chickens than in wild‐type chickens. Our results demonstrate that the D10A‐Cas9 technical platform can facilitate precise and efficient targeted genome engineering and may broaden the range of applications for genome‐edited chickens in practical industrialization and as animal models of human diseases.
The tumor suppressor p53 and the phosphoinositide 3-kinase (PI3K)-Akt pathway have fundamental roles in regulating cell growth, apoptosis and are frequently mutated in cancer. Here, we show that genotoxic stress induces nuclear Akt activation by a p53dependent mechanism that is independent from the canonical membrane-localized PI3K-Akt pathway. Upon genotoxic stress a nuclear p53-PI3,4,5P3 complex is generated in regions devoid of membranes by a nuclear PI3K, and this complex recruits all the kinases required to activate Akt and phosphorylate FOXOs, inhibiting DNA damage-induced apoptosis. Wild-type p53 activates nuclear Akt in an on/off fashion upon stress, whereas mutant p53 stimulates high basal Akt activity, indicating a fundamental difference. The nuclear p53-phosphoinositide signalosome is distinct from the canonical membranelocalized pathway and insensitive to PI3K inhibitors currently in the clinic, underscoring its therapeutic relevance.
Chicken as a food source is one of the most widespread domestic animals, and it has been used extensively as a research model. The clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system is the most efficient and reliable tool for precise genome-targeted modification and has generated considerable excitement for industrial applications, as well as biologic science. Unlike in mammals, germline-transmittable primordial germ cells (PGCs) in chicken were used as an alternative strategy for the production of genetically altered chickens. Here, by combining the CRISPR-Cas9 platform and germ cell-mediated germline transmission, we generated G/G switch gene 2 ( G0S2) knockout (KO) chickens, and G0S2 null KO chickens showed a dramatic reduction of abdominal fat deposition without affecting other economic traits. Additionally, G0S2 null KO chickens had altered fatty acid compositions in their blood and abdominal fat compared with wild-type chickens under normal dietary conditions. The global mRNA sequencing data showed that G0S2 disruption in chickens would activate the adipose tissue-specific peroxisomal oxidation pathway, and enoyl-coenzyme A (CoA), hydratase/3-hydroxyacyl CoA dehydrogenase might be a target molecule in metabolic homeostasis in the chicken adipose tissue. Our results demonstrate that the CRISPR-Cas9 system with chicken PGCs can facilitate the production of specific genome-edited chickens for practical applications, as well as basic research.-Park, T. S., Park, J., Lee, J. H., Park, J.-W., Park, B.-C. Disruption of G/G switch gene 2 ( G0S2) reduced abdominal fat deposition and altered fatty acid composition in chicken.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.