title: Hypomorphic phenotype of Foxn1 gene-modified rats by CRISPR/Cas9 system.
abstract: The Foxn1 gene is known as a critical factor for the differentiation of thymic and skin epithelial cells. This study was designed to examine the phenotype of Foxn1-modified rats generated by the CRISPR/Cas9 system. Guide-RNA designed for first exon of the Foxn1 and mRNA of Cas9 were co-injected into the pronucleus of Crlj:WI zygotes. Transfer of 158 injected zygotes resulted in the birth of 50 offspring (32 %), and PCR identified five (10 %) as Foxn1-edited. Genomic sequencing revealed the deletion of 44 or 60 bp from and/or insertion of 4 bp into the Foxn1 gene in a single allele. The number of T-cells in the peripheral blood lymphocytes of mutant rats decreased markedly. While homozygous deleted mutant rats had no thymus, the mutant rats were not completely hairless and showed normal performance in delivery and nursing. Splicing variants of the indel-mutation in the Foxn1 gene may cause hypomorphic allele, resulting in the phenotype of thymus deficiency and incomplete hairless. In conclusion, the mutant rats in Foxn1 gene edited by the CRISPR/Cas9 system showed the phenotype of thymus deficiency and incomplete hairless which was characterized by splicing variants.
authors.affiliation: Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi, 444-8787, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Goto
authors.affiliation: Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi, 444-8787, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Hara
authors.affiliation: Japan Science Technology Agency, ERATO, Nakauchi Stem Cell and Organ Regeneration Project, Minato-ku, Tokyo, Japan.|The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakauchi
authors.affiliation: Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Hochi
authors.affiliation: Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi, 444-8787, Japan. mhirarin@nips.ac.jp.
authors.forename: Masumi
authors.initials: M
authors.lastname: Hirabayashi
mesh_terms: D000818:Animals; D064113:CRISPR-Cas Systems; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics* / Q000378:metabolism; D006720:Homozygote; D008297:Male; D010641:Phenotype; D011922:Rats, Mutant Strains; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000502:physiology; D013950:Thymus Gland / Q000503:physiopathology*
chemical_list: D051858:Forkhead Transcription Factors; C090140:Whn protein
keywords: CRISPR/Cas9; Foxn1; Knock-out rat; Splicing variant; Thymus deficiency