The application discloses a Toxoplasma SRS29C and ROP16 double-
gene deletion strain and a construction method and application thereof, relates to the technical field of parasite
genetic engineering and
molecular biology. The Toxoplasma SRS29C and ROP16 double-
gene deletion strain is obtained by knocking out SRS29C and ROP16 genes of the ME49 strain through a
CRISPR / Cas9
system. The double-
gene deletion strain constructed by the application has
drug sensitivity change (sensitivity to
ethidium bromide), growth defect
phenotype, and only carries a single screening marker, and under in-vitro culture conditions, the double-
gene deletion strain presents a significant
slow growth trend, and the number of worm-containing bubbles is obviously less than that of the
wild type and single-
gene deletion strain. The double-
gene deletion strain substantially influences the proliferation of the worm body, and provides key data support for exploring the molecular basis of the double-gene deletion leading to the increase of the
drug sensitivity of the worm body and for analyzing the regulation mechanism of the
drug tolerance related path of the Toxoplasma.