CRISPR/Cas9 genome editing used a guide RNA (gRNA; 5'-GAGACAGTAATTGAGGATCCTGG-3'), a double-stranded donor plasmid (containing a splice acceptor (SA), reverse tetracycline-regulated transactivator (rtTA), and a trimerized simian virus 40 polyadenylation (3 pA) to introduce rtTA to the first intron) of the gene. The mutation is anticipated to create a null allele. (J:281590)