Abstract: Provided, in an aspect, is a gene therapy vector, such as for treating retinitis pigmentosa. In an embodiment, a target specific optimization design is performed on a PROM1 gene coding sequence to obtain a nucleotide sequence particularly suitable for efficiently expressing a PROM1 protein in a mammalian cell, and a recombinant AAV virus for expressing a normal human PROM1 protein is constructed. Compared with a coding sequence which is not optimized, the expression level of the optimized PROM1 coding sequence (SEQ ID NO.:1) is increased more than three times. The sequence is particularly suitable for expression in a mammalian cell.