The use of CRISPR technology to ablate germ cells through knockout of the dead end (dnd) gene has been verified in several finfish species . However, the approach is not viable on a large scale because it would require gene editing thousands of production fish. Creating fertile broodstock capable of producing all dnd knockout sterile offspring could help solve this problem. Our study investigates the effectiveness of rescuing dnd knockout-induced sterility in rainbow trout (O. Mykiss ) by simultaneous co-injection of CRISPR-Cas9 construct s targeting the dnd gene, and dnd mRNA (Figure 1.) . We have been successful in introducing insertion and deletion mutations into the dnd gene, and have compelling evidence suggesting that mRNA co-injection can also rescue fertility in the broodstock.
The aquaculture industry is growing rapidly, and adjustments to sterility methodologies is essential for minimizing ecological impact and maximizing production. Our findings could provide valuable solutions to reduce sterilization labor , fish handling, and streamline aquaculture production methods.