Nucleic acid molecule for specifically targeting HBV (Hepatitis B Virus) and expression cassette, expression vector and transformant of nucleic acid molecule

The invention provides a nucleic acid molecule for specifically targeting HBV and an expression cassette, an expression vector and a transformant thereof, the nucleic acid molecule comprises: (a) a nucleotide sequence for coding shRNA (short hairpin Ribonucleic Acid), as shown in SEQ ID NO.1; (b) a nucleotide sequence for coding the sgRNA1, wherein the nucleotide sequence is as shown in SEQ ID NO. 2; (c) a nucleotide sequence for coding sgRNA2, wherein the nucleotide sequence is as shown in SEQ ID NO. 3; and (d) a nucleotide sequence encoding Cas9; the shRNA, the sgRNA1, the sgRNA2 and the Cas9 are respectively positioned in four translation reading frames. The CRISPR/Cas9 system and the RNAi system are integrated on one expression vector, on one hand, the Cas9 protein and shRNA expression level in each cell can be ensured to be consistent, the expression efficiency of the four expression cassettes cannot be mutually influenced, and the highest expression level can be reached, so that the maximum inhibition e