Posted by on June 18, 2020 3:51 am
Categories: Uncategorized

scientists to light as a medium with CRISPR scalpel precision cutting of DNA observed in the ultra-high speed DNA repair

in a series of human cancer cell lines experiments, the Johns Hopkins University School of Medicine scientists say they have successfully use of light as a trigger factor, the use of a method called CRISPR molecular scalpel, quickly to the genomic material for a precise cut, and to observe the specialized cells protein how to repair a gene is cut in the exact position.

6 May 12, published in the journal Science on experimental results, not only reveals the DNA repair process the new details, but, the researchers say, may also accelerate and help people learn about DNA activities, and such activities usually lead to aging and many cancers.

“our new gene-editing system allows in activation after a few seconds of DNA for directional cutting. While the use of the previous technology, gene editing may take longer-even a few hours.” Post-doctoral fellow, Johns Hopkins University Medical Research Team member Yang Liu Dr. said.

in recent years, the powerful CRISPR tool allows scientists to easily change or“edit”DNA sequences and alter gene function, to speed up gene-related conditions of the study pace.

CRISPR according to the bacteria naturally present in the gene editing system transformation, it is called RNA the genetic material of the small sequences as a guide, it is encoded as the cell within a specific genomic DNA sequence matching and binding. The CRISPR molecule also contains a method called Cas9 enzyme, the enzyme can be used as a scalpel excision of the DNA sequence. Then, the cells use their own enzymes and proteins to repair sections of DNA, usually add some DNA sequence, scientists will these sequences inserted into the cell.

Liu said, unable to fast, accurate and“On Demand”way of cutting DNA, for example, using CRISPR)impede the DNA repair process of the research.

in the new experiment, the scientists through the design of a light-sensitive RNA molecules to modify the CRISPR – cas9 complex, which RNA molecule so that the CRISPR complex only in the exposed in the light of a specific wavelength can be cut off the live cells in genomic DNA.

Johns Hopkins University M. D., said:“Our technology has the advantage that researchers can make the CRISPR mechanism to find its target without having to prematurely cut off the gene, until exposed to the light under which it will stop its activities.” PhD students and members of the research team Roger Zou added that:“this allows researchers to more precisely control the DNA when and where to be cut off.”

other research teams have experimented with drugs and light to control the activation of the CRISPR-time, Taekjip Ha, says Dr. He is a Johns Hopkins University Biophysics and biological chemistry, Biophysics and biomedical engineering of the Bloomberg Distinguished Professor, is also a Howard Hughes Medical Institute researcher. His team’s experiments are different, the method is to improve the CRISPR cutting precise timing, and check the protein to repair the DNA Damage Rate.

in the current study, by Johns Hopkins University School of Medicine Biological Physics and Biological Physical Chemistry assistant Professor Ha and Bin Wu, headed by Dr. John Hopkins research group of the electrical pulses transmitted to the human embryonic kidney cells and bone cancer cells, the cells in the cell membrane on the open hole, and having a light-activated RNA molecules of the CRISPR complex to slip into cells. Then the scientists waited 12 hours, so that the CRISPR complex with the genomic DNA of the target point of the binding.

when they used a beam of Light incident on the cell, they keep track of the CRISPR complex to complete the cutting time required.

the research team found that, in the light irradiation onto the cells within 30 seconds, the CRISPR complex has been cutCut more than 50% of the target.

in order to further study DNA repair time, Johns Hopkins scientists have tracked involved in DNA repair proteins when is the grabbed DNA incision。 They determined that the repair protein in the CRISPR activation after two minutes begins to work, the repair in 15 minutes after completion.

“we have demonstrated that light-activated gene cut very fast, and in biomedical research with a wide range of potential applications.”“ Reveal the CRISPR gene cutting time, allows us to more accurately see the biological process.” Ha and Johns Hopkins University team will be this technology called“very fast with the need to strain CRISPR to”.

the Ha also noted that the light-activated than the drug could in the cell is widely spread to provide better position control.

Johns Hopkins University research team also used a high-resolution microscope“to observe the”repair proteins how to and the living cells of the CRISPR cut site interactions.

they use these microscopes and the focused beam is displayed, you can activate the CRISPR cutting human cells common to the two gene copies to one. They say that this ability to use CRISPR for research and ultimately treatment with only one abnormal gene copy-related disease offers the opportunity, for example Huntington’s disease.

“there is a very large research groups to study DNA damage and its impact interested.” Ha say.“ We have developed the technology very suitable to study this problem.”

Ha pointed out, scientists often use ionizing radiation or chemicals to study DNA damage. He said that, although these methods can also be very fast, but they are not for a specific genome position.

the team has for this study is described in CRISPR technology applied for a provisional patent.

compile/proactive economist APP Information Group


Published at Fri, 18 Jun 2020 07:50 :46 +0000