This strain was established by targeting Rag2 gene in F344/Jcl using CRISPR/Cas9 system. gRNA to Rag2: AACATAGCCTTAATTCAACCAGG (PAM: last AGG); Cas 9 mRNA transcribed from T7-NLS hCas9-pA (RDB13130) was used for the system. Gene transfer was performed by electroporation. This strain shows severe combined immunodeficiency (SCID) caused by 1-bp insertion in Rag2 gene on chromosome 3. This strain grows normally under SPF condition.