CRISPR/cas9 genome editing used guide RNAs to target upstream [AGCCAGTCCGCCACTAAAAT ; GACCTATTTTAGTGGCGGAC] and downstream [CCCCCCGGTTACTTGTGATT ; CACCTAATCACAAGTAACCG] of exon 3. Progeny were screened by DNA sequencing of the targeted region, which identified founder 4341 harboring a 2449-nt deletion that resulted in the complete loss of exon 3. (J:101977)