Mouse Genome Informatics
involves: 129 * C57BL/6 * CD-1
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
• underrepresented at weaning

• at E13.5 the size of the mesenchymal cell condensations underlying the posterior part of the dental lamina is reduced, but the dental papilla of the first molar has formed
• in the upper incisors ameloblasts are present at 2 months of age but absent by 5 months
• in the upper incisors ameloblasts fail to elongate and produce only a thin layer of pre-enamel
• at P0 all third molars are arrested prior to the bud stage and the lower second molars are arrested at the bud stage
• at P0 the lower first molars have reached the bell stage but lack polarization and alignment of the ameloblasts and odontoblasts
• at P0 the upper first and second molars are mostly growth retarded
• all mice lack lower incisors
• the lower first molars show significant attrition and formation of reparative dentin
• the upper third and lower second and third molars are unilaterally or bilaterally absent
• lower third molars and incisors fail to erupt and other teeth in the lower jaw may also fail to erupt
• irregular dentin formation is indicated by the presence of 'contour lines of Owen'
• the upper incisors lack enamel; however enamel formation in the molars is normal
• more severe tooth loss than in Pax9tm1Hpt homozygotes with all mice lacking at least 4 teeth (oligodontia) and some lacking all lower teeth


endocrine/exocrine glands
• thymus morphology is normal and no signs of defective parathyroid or ultimobranchial body function (as shown by normal calcium and phosphate homeostasis) are seen (J:104121)

Mouse Models of Human Disease
Tooth Agenesis, Selective, 3; STHAG3 604625 J:104121