Fig. 7

Generation of floxed mice by the enhanced PITCh system. a Targeting strategy for the generation of floxCol12a1 mice by the enhanced PITCh system. Purple highlights indicate microhomologies between endogenous Col12a1 locus and PITCh-donor. Blue characters indicate CRISPR target sequences. Red characters indicate protospacer adjacent motif (PAM) sequences. Yellow lightnings indicate DSB sites. b Schematic diagram of pronuclear injection of Cas9 protein, Col12a1-left, -right, and gRNA-s1 crRNAs, tracrRNA, PITCh-donor, and Exo1 mRNA. The red, purple, and blue boxes indicate the insert, Col12a1 microhomologies, and gRNA-s1 target sequences, respectively. c PCR screenings of newborns. d PCR-RFLP (restriction fragment length polymorphism) screenings of floxed newborn mice. e Summary of floxCol12a1 mouse production by the enhanced PITCh system. f Sequences of boundaries between Col12a1 and LoxPs. Blue, green, and red characters indicate microhomologies, HindIII sites, and LoxPs, respectively. g in vitro Cre-recombination assay. Cloned PCR products of flox alleles from three floxCol12a1 mice and genomic PCR of wildtype were incubated with or without Cre-recombinase. LF: left forward primer, RR: right reverse primer, MH: microhomology, M: molecular marker, and WT: wildtype