SummaryOver the last three decades, the development of new genome editing techniques, such as ODM, TALENs, ZFNs and the CRISPR‐Cas system, has led to significant progress in the field of plant and animal breeding. The CRISPR‐Cas system is the most versatile genome editing tool discovered in the history of molecular biology because it can be used to alter diverse genomes (e.g. genomes from both plants and animals) including human genomes with unprecedented ease, accuracy and high efficiency. The recent development and scope of CRISPR‐Cas system have raised new regulatory challenges around the world due to moral, ethical, safety and technical concerns associated with its applications in pre‐clinical and clinical research, biomedicine and agriculture. Here, we review the art, applications and potential risks of CRISPR‐Cas system in genome editing. We also highlight the patent and ethical issues of this technology along with regulatory frameworks established by various nations to regulate CRISPR‐Cas‐modified organisms/products.
SUMMARYTransient expression of the transcription factor neurogenin-3 marks progenitor cells in the pancreas as they differentiate into islet cells. We developed a transgenic mouse line in which the surrogate markers secreted alkaline phosphatase (SeAP) and enhanced green florescent protein (EGFP) can be used to monitor neurogenin-3 expression, and thus islet cell genesis. In transgenic embryos, cells expressing EGFP lined the pancreatic ducts. SeAP was readily detectable in embryos, in the media of cultured embryonic pancreases and in the serum of adult animals. Treatment with the γ-secretase inhibitor DAPT, which blocks Notch signaling, enhanced SeAP secretion rates and increased the number of EGFP-expressing cells as assayed by fluorescence-activated cell sorting (FACS) and immunohistochemistry in cultured pancreases from embryos at embryonic day 11.5, but not in pancreases harvested 1 day later. By contrast, treatment with growth differentiation factor 11 (GDF11) reduced SeAP secretion rates. In adult mice, partial pancreatectomy decreased, whereas duct ligation increased, circulating SeAP levels. This model will be useful for studying signals involved in islet cell genesis in vivo and developing therapies that induce this process.
The present study aims at using the gene expression as biomarkers in the identification of the biological effects of low and high doses of ionizing radiation (X-ray) in white mice Mus musculus Balb/C, ages 4-6 weeks, weight 30-40 grams. Seventy-two white mice (36 males and 36 females) were divided into two groups; their whole body was exposed to 5 cGy (rad) and 100 cGy (rad) of X-ray radiation at a dose rate of 200 cGy/min, in addition to the control group. Total RNA was successfully isolated using Trizol method from blood and liver samples of mice after 6, 48 hours and 10 days of exposure to radiation as well as of the control group. The RNA concentration was determined spectrophotometrically by measuring their absorbance using nucleic acid and protein analyzer that dependent on the ratio A 260 /A 280 of the wavelength which lead to the determination of RNA purity, it ranged from 1.79-2.1 in all mice groups. RNA integrity and quality were confirmed by agarose gel electrophoresis.Three bands such as 28s, 18s and 5s appeared in a visible manner. This study involved the reverse transcription (RT) of the RNA for the manufacture of complementary DNA (cDNA) using the polymerase chain reaction (PCR) for investigation on above-mentioned groups of animals. Complementary DNA was used in amplification of genes used in the present study, one type of specialized primers were selected for the gene as X-Ray repair cross complementing group 4 (XRCC4), which have a relation with ionizing radiation in addition to the primers for internal control (β-actin) gene. The optimal conditions for PCR were determined using a dye (SYBR ® Green 1).This should be done before using the device quantitative real time-PCR (QRT-PCR) in experiments. The products of replicated specialized primers for the genes concerned and the cDNA for the studied samples were electrophoretically separated in agarose gels .The banding profiles were visualized by ethidium bromide staining, as the molecular weight was 183 bp nitrogen-base pair for XRCC4 gene.The changes in the gene expression for the genes concerned were determined by measuring the quantitative levels of expression in the blood and liver samples of the group of mice after 6, 48 hours and 10 days of exposure to X-ray, in addition to the control group using the device QRT-PCR.The presence of significant reduction (p <0.05) in the amount of gene expression for the XRCC4 gene in samples of blood and liver from mice exposed to both doses of 5 cGy and 100 cGy after 6, 48 hours and 10 days of exposure to radiation. This gene was down-regulation after 6 hours in the blood samples of mice exposed to these doses compared to the control group. In contrast, there were to these finding, significant increases (p <0.05) in the amounts of gene expression of this gene in the liver tissues of mice exposed to both doses after 6 and 48 hours of exposure to radiation. This gene also showed up-regulation after 48 hours in the liver tissue of mice exposed to 5 cGy doses, while the up-regulation was appeared after 6 hours o...
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.