An Accessible Protocol for the Generation of CRISPR-Cas9 Knockouts Using INDELs in Zebrafish

The ability to create targeted mutations in specific genes, and therefore a loss-of-function condition, provides essential information about their endogenous functions during development and homeostasis. The discovery that CRISPR-Cas9 can target specific sequences according to base-pair complementarity and readily create knockouts in a desired gene has elevated the implementation of genetic analysis in numerous organisms. As CRISPR-Cas9 has become a powerful tool in a number of species, multiple methods for designing, creating, and screening editing efficiencies have been published, each of which has unique benefits. This chapter presents a cost-efficient, accessible protocol for creating knockout mutants in zebrafish using insertions/deletions (INDELS), from target site selection to mutant propagation, using basic laboratory supplies. The presented approach can be adapted to other systems, including any vertebrate species.