Generation and characterization of GRK6^−/−mice. (A) Strategy for introducing stop codon in the mouse GRK6 gene. The gRNA 5′ and gRNA 3′ were combined with Cas9 messenger RNA for subsequent cytoplasmic injection of fertilized mouse eggs. Embryos were then transferred to pseudopregnant C57BL/6 female mice. After birth, 10-day-old mice were tail-snipped, and genomic DNA was extracted for genotyping and sequencing. The founder mice were each bred to the F1 generation using C57BL/6 mice for further analysis. CRISPR-mediated genome editing introduced a premature stop codon in exon 2. (B) Deletion of GRK6 does not affect GRK2 or GRK5 protein expression in mouse brain (i; N = 3) or platelets (ii; N = 2). Lysates were probed for GRK6 before being successively reprobed for GRK5, GRK2, or actin.