Efficient and heritable gene targeting in tilapia by CRISPR/Cas9

Area of Science:

• Genetics
• Molecular Biology
• Aquaculture

Background:

• Gene function studies in non-model animals are challenging due to limited gene knockout methods.
• The CRISPR/Cas9 system offers a breakthrough for precise genome editing.

Purpose of the Study:

• To demonstrate the efficacy of CRISPR/Cas9 for targeted gene disruption in tilapia.
• To establish a method for generating heritable loss-of-function mutants in a non-model fish species.

Main Methods:

• Utilized CRISPR/Cas9 to target genes like nanos2, nanos3, dmrt1, and foxl2 in tilapia.
• Assessed gene editing efficiency, germline transmission, and resulting phenotypes.
• Employed techniques including GFP labeling, Vasa staining, and immunohistochemistry.

Main Results:

• Achieved high gene disruption efficiencies (up to 95%) for targeted genes.
• Successfully transmitted CRISPR/Cas9-induced mutations (dmrt1, foxl2) to the F1 generation.
• Observed significant phenotypes, including germ cell deficiency and gonadal masculinization, in edited tilapia.

Conclusions:

• CRISPR/Cas9 is an effective and heritable gene editing tool for tilapia.
• This technology provides a valuable approach for functional genomics and genetic engineering in non-model teleost species.