Zhang Fengs team successfully developed new gene scissors to reduce miss-distance effect

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 Zhang Fengs team successfully developed new gene scissors to reduce miss-distance effect


Beijing, Jan. 22, Science and Technology Daily (Reporter Zhang Menglan) According to a paper published by the British Journal Nature Communications on Jan. 22, Zhang Fengs team from the Bode Institute of Harvard University, Massachusetts Institute of Technology, reported the third RISPR-Cas system that can edit the human cell genome. In the experiment, CRISPR-Cas12b system showed higher specificity to target sequence than Cas9.

CRISPR gene editing technology is called game changer in the field of life sciences. This breakthrough technology discovers, excises and replaces specific parts of DNA through a special programmed enzyme called Cas9. Therefore, CRISPR-Cas9 is a multi-functional genome editing system.

But Cas9 is not the only RNA-directed nuclease in the Cas protein family (an enzyme that cleaves DNA). In addition to Cas9, the researchers also found Cas12a and Cas12b. Cas12a has been developed as a genome editing tool, while Cas12b has not yet been fully developed, at least partly because of its thermophilic nature.

Zhang Feng and his colleagues studied Cas12b because it is smaller than Cas9 or Cas12a and easier to deliver between cells via viral vectors. But Cas12b, the original structure, cleaves non-target single strands in double-stranded DNA. To solve this problem, the research team redesigned Cas12b to enhance its activity at body temperature (37 degrees Celsius). Compared with Cas9, the redesigned Cas12b has higher specificity for target sequences in cell culture experiments. Researchers say much remains to be done to transform Cas12b into a widely used tool like Cas9, but the emergence of a third potential genome editing system will give researchers around the world more choices. Previously, CRISPR triggered a patent war because of its huge commercial value. After the key ruling of the Patent Trial and Appeals Board of the US Patent and Trademark Office in February 2017, the University of California, Berkeley, filed an appeal. In September 2018, the Federal Circuit Court of Appeals upheld the ruling, and Zhang Fengs institution continued to gain the upper hand. Source: Wang Fengzhi_NT2541, responsible editor of Science and Technology Daily - China Science and Technology Network

Zhang Feng and his colleagues studied Cas12b because it is smaller than Cas9 or Cas12a and easier to deliver between cells via viral vectors. But Cas12b, the original structure, cleaves non-target single strands in double-stranded DNA. To solve this problem, the research team redesigned Cas12b to enhance its activity at body temperature (37 degrees Celsius). Compared with Cas9, the redesigned Cas12b has higher specificity for target sequences in cell culture experiments.

Researchers say much remains to be done to transform Cas12b into a widely used tool like Cas9, but the emergence of a third potential genome editing system will give researchers around the world more choices.

Previously, CRISPR triggered a patent war because of its huge commercial value. After the key ruling of the Patent Trial and Appeals Board of the US Patent and Trademark Office in February 2017, the University of California, Berkeley, filed an appeal. In September 2018, the Federal Circuit Court of Appeals upheld the ruling, and Zhang Fengs institution continued to gain the upper hand.