The parental Gt(ROSA)26Sortm6(CAG-ZsGreen1)Hze strain containing a pair of FRT sites flanking the reporter, in addition to the flox-stop cassette placed between the CAG promoter and ZsGreen was mutated to eliminate the downstream FRT site with Crispr-CAS9aided targeting. The microinjection of the guide RNA and CAS9 constructs into fertilized embryos generated the modified alleles, named R26Z10, was established and used in the study. (J:297537)