Abstract: Provided are a fusion protein that improves gene editing efficiency and an application thereof. The fusion protein comprises a single-stranded DNA binding protein functional domain, nucleoside deaminase and nuclease. According to CBEs, when carrying our base conversion from C-G to T-A, nucleoside deaminase such as cytosine deaminase carries out deamination by using single-stranded DNA as a substrate, and by re-fusing the single-stranded DNA binding protein functional domain on the fusion protein of the nucleoside deaminase and nuclease, the chance of single-stranded DNA being exposed to the nucleoside deaminase is greatly increased, thereby significantly improving base editing efficiency. The present disclosure provides a breakthrough improvement of single-base gene editing technology and can greatly promote the application thereof in aspects such as gene editing, gene therapy, cell therapy, animal model making, and crop genetic breeding.

Abstract: Provided are two split single-base gene editing systems. Intein-mediated split BE3, saKKH-BE3 and ABE7.10 are separately developed by using the existing protein structure information of spCas9 and saCas9 and splitting methods thereof, and have targeted gene mutation efficiency equivalent to that of unsplit BE3, saKKH-BE3 and ABE7.10 working system, thereby making possible package into an AAV for delivery.

Abstract: An exploitation method and an exploitation well pattern for coalbed methane in a low-permeability coalbed. The method comprises: determining a maximum principal stress direction in a low-permeability coalbed; disposing at least two large-roadway horizontal wells in the low-permeability coalbed; disposing a plurality of production wells on two sides of a horizontal segment of each of the at least two large-roadway horizontal wells, wherein a diameter of each of the production wells is smaller than a diameter of the horizontal segment; exploiting the coalbed methane in the low-permeability coalbed through the at least two large-roadway horizontal wells and the plurality of production wells. Through the horizontal segments of the large-roadway horizontal wells perpendicular to the maximum principal stress direction, it promotes stress release in low-permeability coalbed to form more fracture channels, thereby improving the exploitation efficiency of the coalbed methane in the low-permeability coalbed.

Abstract: The present disclosure discloses an exploitation method and an exploitation well pattern for coalbed methane in a low-permeability coalbed. The method comprises: determining a maximum principal stress direction in a low-permeability coalbed (1); disposing at least two large-roadway horizontal wells (3) in the low-permeability coalbed (1); disposing a plurality of production wells (4) on two sides of a horizontal segment (31) of each of the at least two large-roadway horizontal wells (3), wherein a diameter of each of the production wells (4) is smaller than a diameter of the horizontal segment (31) of the large-roadway horizontal well (3); exploiting the coalbed methane in the low-permeability coalbed through the at least two large-roadway horizontal wells (3) and the plurality of production wells (4).