Novel human mutation and CRISPR/Cas genome-edited mice reveal the importance of C-terminal domain of MSX1 in tooth and palate development

• Published in: Scientific reports Vol. 6; no. 1; p. 38398
• Main Authors: Mitsui, Silvia Naomi, Yasue, Akihiro, Masuda, Kiyoshi, Naruto, Takuya, Minegishi, Yoshiyuki, Oyadomari, Seiichi, Noji, Sumihare, Imoto, Issei, Tanaka, Eiji
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.12.2016; Nature Publishing Group
• Subjects: 45/23; 45/41; 631/337; 64/60; 692/699; Adolescent; Adult; Animals; Anodontia - genetics; Anodontia - metabolism; Anodontia - pathology; Base Sequence; Cleft Lip - genetics; Cleft Lip - metabolism; Cleft Lip - pathology; Cleft lip/palate; Cleft Palate - genetics; Cleft Palate - metabolism; Cleft Palate - pathology; Craniofacial growth; CRISPR; CRISPR-Cas Systems; Disease Models, Animal; Embryo, Mammalian; Female; Frameshift mutation; Gene Editing - methods; Gene Expression; Genetic Loci; Genomes; Heterozygote; Homeobox; Homology; Homozygote; Humanities and Social Sciences; Humans; Incisor - abnormalities; Incisor - growth & development; Incisor - metabolism; Incisors; Male; Mice; Molar, Third - abnormalities; Molar, Third - growth & development; Molar, Third - metabolism; Molars; MSX1 Transcription Factor - genetics; MSX1 Transcription Factor - metabolism; multidisciplinary; Mutation; Palate - abnormalities; Palate - growth & development; Palate - metabolism; Pedigree; Premolars; Protein Domains; Science; Teeth
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep38398

Several mutations, located mainly in the MSX1 homeodomain, have been identified in non-syndromic tooth agenesis predominantly affecting premolars and third molars. We identified a novel frameshift mutation of the highly conserved C-terminal domain of MSX1, known as Msx homology domain 6 (MH6), in a Japanese family with non-syndromic tooth agenesis. To investigate the importance of MH6 in tooth development, Msx1 was targeted in mice with CRISPR/Cas system. Although heterozygous MH6 disruption did not alter craniofacial development, homozygous mice exhibited agenesis of lower incisors with or without cleft palate at E16.5. In addition, agenesis of the upper third molars and the lower second and third molars were observed in 4-week-old mutant mice. Although the upper second molars were present, they were abnormally small. These results suggest that the C-terminal domain of MSX1 is important for tooth and palate development, and demonstrate that that CRISPR/Cas system can be used as a tool to assess causality of human disorders in vivo and to study the importance of conserved domains in genes.