Genotyping-free Selection of Double Allelic Gene Edited Medaka Using Two Different Fluorescent Proteins.
Ontology highlight
ABSTRACT:
SUBMITTER: Murakami Y
PROVIDER: S-EPMC8438436 | biostudies-literature | 2017 Dec
REPOSITORIES: biostudies-literature
Publications
Genotyping-free Selection of Double Allelic Gene Edited Medaka Using Two Different Fluorescent Proteins.
Murakami Yu Y Ansai Satoshi S Yonemura Akari A Kinoshita Masato M
Bio-protocol 20171220 24
This protocol describes a simple genotyping using two different colors of fluorescent protein genes inserted at the target locus. This method makes it possible to determine the genotype of each individual simply by observing the fluorescence later than F1 generation. ...[more]
Similar Datasets
Project description:Fish are ideally suited for in vivo-imaging due to their transparency at early stages combined with a large genetic toolbox. Key challenges to further advance imaging are fluorophore selection, immobilization of the specimen and approaches to eliminate pigmentation. We addressed all three and identified the fluorophores and anaesthesia of choice by high throughput time-lapse imaging. Our results indicate that eGFP and mCherry are the best conservative choices for in vivo-fluorescence experiments, when availability of well-established antibodies and nanobodies matters. Still, mVenusNB and mGFPmut2 delivered highest absolute fluorescence intensities in vivo. Immobilization is of key importance during extended in vivo imaging. Here, traditional approaches are outperformed by mRNA injection of α-Bungarotoxin which allows a complete and reversible, transient immobilization. In combination with fully transparent juvenile and adult fish established by the targeted inactivation of both, oca2 and pnp4a via CRISPR/Cas9-mediated gene editing in medaka we could dramatically improve the state-of-the art imaging conditions in post-embryonic fish, now enabling light-sheet microscopy of the growing retina, brain, gills and inner organs in the absence of side effects caused by anaesthetic drugs or pigmentation.
| S-EPMC6405165 | biostudies-literature
Project description:BackgroundThe diversity of genotyping markers of Plasmodium falciparum depends on transmission intensity. It has been reported that the diversity of the merozoite surface protein 2 (msp2) is greater in areas of high compared to low endemicity, however, results for msp1 were inconsistent. These previous reports relied on low resolution genotyping techniques.MethodsIn the present study, a high-resolution capillary electrophoresis-based technique was applied to genotype samples from areas of different endemicity in Papua New Guinea and Tanzania. For both endemic settings, the diversity of msp1 and msp2 was investigated; the mean multiplicity of infection (MOI) and the FST values were determined to investigate whether more accurate sizing generates different results.Results and conclusionThe results of the present study confirmed previous reports of a higher mean MOI for both marker genes and increased genetic diversity in areas of higher endemicity as estimated by the total number of distinct alleles for msp2. For msp1 a minor increase in diversity was observed. Measures of between population variance in allele frequencies (FST) indicated little genetic differentiation for both marker genes between the two populations from different endemic settings. MOI adjusted for the probability of multiple infections sharing the same allele was estimated by using the msp2 allele frequency distribution and the distribution of observed numbers of concurrent infections. For the high-resolution typing technique applied in this study, this adjustment made little difference to the estimated mean MOI compared to the observed mean MOI.
| S-EPMC2774868 | biostudies-literature
Project description:Gene-edited pigs for agricultural and biomedical applications are typically generated using somatic cell nuclear transfer (SCNT). However, SCNT requires the use of monoclonal cells as donors, and the time-consuming and laborious monoclonal selection process limits the production of large populations of gene-edited animals. Here, we developed a rapid and efficient method named RE-DSRNP (reporter RNA enriched dual-sgRNA/CRISPR-Cas9 ribonucleoproteins) for generating gene-edited donor cells. RE-DSRNP takes advantage of the precise and efficient editing features of dual-sgRNA and the high editing efficiency, low off-target effects, transgene-free nature, and low cytotoxic characteristics of reporter RNA enriched RNPs (CRISPR-Cas9 ribonucleoproteins), thus eliminating the need for the selection of monoclonal cells and thereby greatly reducing the generation time of donor cells from 3-4 weeks to 1 week, while also reducing the extent of apoptosis and chromosomal aneuploidy of donor cells. We applied RE-DSRNP to produce cloned pigs bearing a deletion edit of the wild-type p53-induced phosphatase 1 (WIP1) gene: among 32 weaned cloned pigs, 31 (97%) carried WIP1 edits, and 15 (47%) were homozygous for the designed fragment deletion, and no off-target event was detected. The WIP1 knockout (KO) pigs exhibited male reproductive disorders, illustrating the utility of RE-DSRNP for rapidly generating precisely edited animals for functional genomics and disease research. RE-DSRNP's strong editing performance in a large animal and its marked reduction in the required time for producing SCNT donor cells support its application prospects for rapidly generating populations of transgene-free cloned animals.
| S-EPMC8817169 | biostudies-literature
Project description:Despite the great achievements in genome editing, accurately detecting mutations induced by sequence-specific nucleases is still a challenge in plants, especially in polyploidy plants. An efficient detection method is particularly vital when the mutation frequency is low or when a large population needs to be screened. Here, we applied purified CRISPR ribonucleoprotein complexes to cleave PCR products for genome-edited mutation detection in hexaploid wheat and diploid rice. We show that this mutation detection method is more sensitive than Sanger sequencing and more applicable than PCR/RE method without the requirement for restriction enzyme site. We also demonstrate that this detection method is especially useful for genome editing in wheat, because target sites are often surrounded by single nucleotide polymorphisms. Using this screening method, we were also able to detect foreign DNA-free tagw2 mutations induced by purified TALEN protein. Finally, we show that partial base editing mutations can also be detected using high-fidelity SpCas9 variants or FnCpf1. The PCR/RNP method is low-cost and widely applicable for rapid detection of genome-edited mutation in plants.
| S-EPMC6230946 | biostudies-literature
Project description:Molecular imaging employing fluorescent proteins has been widely used to highlight specific reactions or processes in various fields of the life sciences. Despite extensive improvements of the fluorescent tag, this technology is still limited in the study of molecular events in the extracellular milieu. This is partly due to the presence of cysteine in the fluorescent proteins. These proteins almost cotranslationally form disulfide bonded oligomers when expressed in the endoplasmic reticulum (ER). Although single molecule photobleaching analysis showed that these oligomers were not fluorescent, the fluorescent monomer form often showed aberrant behavior in folding and motion, particularly when fused to cysteine-containing cargo. Therefore we investigated whether it was possible to eliminate the cysteine without losing the brightness. By site-saturated mutagenesis, we found that the cysteine residues in fluorescent proteins could be replaced with specific alternatives while still retaining their brightness. cf(cysteine-free)SGFP2 showed significantly reduced restriction of free diffusion in the ER and marked improvement of maturation when fused to the prion protein. We further applied this approach to TagRFP family proteins and found a set of mutations that obtains the same level of brightness as the cysteine-containing proteins. The approach used in this study to generate new cysteine-free fluorescent tags should expand the application of molecular imaging to the extracellular milieu and facilitate its usage in medicine and biotechnology.
| S-EPMC3359384 | biostudies-literature
Project description:Fluorescent proteins offer exceptional labeling specificity in living cells and organisms. Unfortunately, their photophysical properties remain far from ideal for long-term imaging of low-abundance cellular constituents, in large part because of their poor photostability. Despite widespread engineering efforts, improving the photostability of fluorescent proteins remains challenging due to lack of appropriate high-throughput selection methods. Here, we use molecular dynamics guided mutagenesis in conjunction with a recently developed microfluidic-based platform, which sorts cells based on their fluorescence photostability, to identify red fluorescent proteins with decreased photobleaching from a HeLa cell-based library. The identified mutant, named Kriek, has 2.5- and 4-fold higher photostability than its progenitor, mCherry, under widefield and confocal illumination, respectively. Furthermore, the results provide insight into mechanisms for enhancing photostability and their connections with other photophysical processes, thereby providing direction for ongoing development of fluorescent proteins with improved single-molecule and low-copy imaging capabilities.
| S-EPMC4323946 | biostudies-literature
Project description:Medaka is a model organism in medicine, genetics, developmental biology and population genetics. Lab stocks composed of more than 100 local wild populations are available for research in these fields. Thus, medaka represents a potentially excellent bioresource for screening disease-risk- and adaptation-related genes in genome-wide association studies. Although the genetic population structure should be known before performing such an analysis, a comprehensive study on the genome-wide diversity of wild medaka populations has not been performed. Here, we performed genotyping-by-sequencing (GBS) for 81 and 12 medakas captured from a bioresource and the wild, respectively. Based on the GBS data, we evaluated the genetic population structure and estimated the demographic parameters using an approximate Bayesian computation (ABC) framework. The genome-wide data confirmed that there were substantial differences between local populations and supported our previously proposed hypothesis on medaka dispersal based on mitochondrial genome (mtDNA) data. A new finding was that a local group that was thought to be a hybrid between the northern and the southern Japanese groups was actually an origin of the northern Japanese group. Thus, this paper presents the first population-genomic study of medaka and reveals its population structure and history based on chromosomal genetic diversity.
| S-EPMC6325896 | biostudies-literature
Project description:The emergence in recent years of DNA editing technologies-Zinc finger nucleases (ZFNs), transcription activator-like effector (TALE) guided nucleases (TALENs), clustered regularly interspaced short palindromic repeats (CRISPR)/Cas family enzymes, and Base-Editors-have greatly increased our ability to generate hundreds of edited cells carrying an array of alleles, including single-nucleotide substitutions. However, the infrequency of homology-dependent repair (HDR) in generating these substitutions in general requires the screening of large numbers of edited cells to isolate the sequence change of interest. Here we present a high-throughput method for the amplification and barcoding of edited loci in a 96-well plate format. After barcoding, plates are indexed as pools which permits multiplexed sequencing of hundreds of clones simultaneously. This protocol works at high success rate with more than 94% of clones successfully genotyped following analysis.
| S-EPMC6481090 | biostudies-literature
Project description:In the directed evolution experiments of EGFP or StayGold, the objective was to blue-shift the excitation light spectrum of GFP towards shorter wavelengths, resulting in an enhancement of fluorescence intensity upon 405 nm laser excitation. This facilitates the advancement of novel fluorescent proteins. These experiments represent a category of experiments that utilize REPLACE to achieve discontinuous directed evolution through FACS sorting (screening).
2024-09-30 | GSE271876 | GEO
Project description:RNA-binding proteins (RBPs) perform many essential functions in the post-transcriptional control of gene expression. If we were able to engineer RBPs with new specificity, it would also become possible to develop new tools to control and investigate gene expression pathways. Molecular evolution methods such as phage display have been introduced to achieve this goal, but the large interface between these proteins and RNA relative to the size of library that can be constructed limits the efficacy of this method. In order to increase the diversity of libraries used for selection of RBPs, we applied the emulsion-based in vitro compartmentalization (IVC) method to select RBPs with defined specificity. A new approach was developed to link genotype and phenotype by fusing the target RBP to zinc finger proteins (ZFPs) that bind to a cognate DNA sequence inserted upstream of the promoter. The expressed fusion protein (ZFP-RBP) binds to its encoding DNA with high affinity via the ZFP target-binding site. After breaking the emulsion, the RBP can be selected based on its affinity for a biotinylated RNA bait. We demonstrate the effectiveness of this method that should enable the selection of RBPs with new specificity or improved affinity.
| S-EPMC2577342 | biostudies-literature