written by Thomas Clements CRISPR has been hailed as one of the most promising gene editing technologies and promises to revolutionize precision medicine
Using a new coding strategy, researchers at Columbia and New York Genome Center maximize the data-storage capacity of DNA molecules.
BigField GEG Tech's insight:
In a new study in Science, a pair of researchers at Columbia University and the New York Genome Center (NYGC) show that an algorithm designed for streaming video on a cellphone can unlock DNA’s nearly full storage potential by squeezing more information into its four base nucleotides. They demonstrate that this technology is also extremely reliable.
In this work, the authors developed a CRISPR screen using ~18,000 single guide RNAs targeting >700 kilobases surrounding the genes NF1, NF2, and CUL3, which are involved in BRAF inhibitor resistance in melanoma. They find that noncoding locations that modulate drug resistance also harbor predictive hallmarks of noncoding function. With a subset of regions at the CUL3 locus, they demonstrate that engineered mutations alter transcription factor occupancy and long-range and local epigenetic environments, implicating these sites in gene regulation and chemotherapeutic resistance. Through their expansion of the potential of pooled CRISPR screens, they provide tools for genomic discovery and for elucidating biologically relevant mechanisms of gene regulation.
Here, the authors construct logic AND circuits by integrating multiple split dCas9 domains, which is useful to reduce the size of synthetic circuits. In addition, we engineer sensory switches by exchanging split dCas9 domains, allowing differential regulations on one gene, or activating two different genes in response to cell-type specific microRNAs. Therefore, they provide a valuable split-dCas9 toolkit to engineer complex transcription controls, which may inspire new biomedical applications.
The scientists describe structure-guided engineering of a CRISPR-Cas9 complex to mediate efficient transcriptional activation at endogenous genomic loci. In this way, they demonstrated multiplexed activation of ten genes simultaneously, and the upregulation of long intergenic non-coding RNA (lincRNA) transcripts.
Scientists at Karolinska Institutet and Gurdon Institute in Cambridge, United Kingdom have identified a novel mechanism that allows pluripotent stem cells to maintain their genome in an unpacked state, and thereby maintain their unique property to...
BigField GEG Tech's insight:
A discovered which would enhance research in cell therapy. Great!
Genome editing has potential for the targeted correction of germline mutations. Here we describe the correction of the heterozygous MYBPC3 mutation in human preimplantation embryos with precise CRISPR–Cas9-based targeting accuracy and high homology-directed repair efficiency by activating an endogenous, germline-specific DNA repair response. Induced double-strand breaks (DSBs) at the mutant paternal allele were predominantly repaired using the homologous wild-type maternal gene instead of a synthetic DNA template. By modulating the cell cycle stage at which the DSB was induced, we were able to avoid mosaicism in cleaving embryos and achieve a high yield of homozygous embryos carrying the wild-type MYBPC3 gene without evidence of off-target mutations. The efficiency, accuracy and safety of the approach presented suggest that it has potential to be used for the correction of heritable mutations in human embryos by complementing preimplantation genetic diagnosis. However, much remains to be considered before clinical applications, including the reproducibility of the technique with other heterozygous mutations.
The expansion of trinucleotide repeats has been linked to several neurodegenerative disorders.
BigField GEG Tech's insight:
CAG/CTG repeat expansions cause over 13 neurological diseases that remain without a cure. Because longer tracts cause more severe phenotypes, contracting them may provide a therapeutic avenue. In this study, the scientists find that inducing double-strand breaks within the repeat tract causes instability in both directions. In contrast, the CRISPR-Cas9 D10A nickase induces mainly contractions independently of single-strand break repair. They propose that DNA gaps lead to contractions and that the type of DNA damage present within the repeat tract dictates the levels and the direction of CAG repeat instability. This study paves the way towards deliberate induction of CAG/CTG repeat contractions in vivo.
Here, the scientists systematically analyze whether CRISPR approaches are suitable to target lncRNAs. Many lncRNAs are derived from bidirectional promoters or overlap with promoters or bodies of sense or antisense genes. In a genome-wide analysis, they find only 38% of 15929 lncRNA loci are safely amenable to CRISPR applications while almost two-thirds of lncRNA loci are at risk to inadvertently deregulate neighboring genes. They conclude that, despite the advantages of CRISPR/Cas9 to modulate expression bidirectionally and in cis, approaches based on siPOOL or Antisense Oligo may be the better choice to target specifically the transcript from complex loci.
Scientific Reports is an online, open access journal from the publishers of Nature. The 2014 Impact Factor for Scientific Reports is 5.578.
BigField GEG Tech's insight:
In this study, the authors used the CRISPR cas9 system to target HBV genome. In this way, they manage to cleave episomal and integrated HBS genome but also to disrupt HBV replication.
The authors created a platform which could enable long-term cellular recorders for environmental and biomedical applications, biological state machines, and enhanced genome engineering strategies.
To get content containing either thought or leadership enter:
To get content containing both thought and leadership enter:
To get content containing the expression thought leadership enter:
You can enter several keywords and you can refine them whenever you want. Our suggestion engine uses more signals but entering a few keywords here will rapidly give you great content to curate.