Mouse Genome Informatics
involves: 129S2/SvPas * C57BL/6
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
• in 13% of mice all teeth are present but the lower incisors and third molars are hypoplastic
• in 35% of mice tooth defects differ between the right and left halves of the lower jaw
• 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 most cases the lower incisors are absent
• the lower first molars show significant attrition and formation of reparative and reactionary dentin
• the upper and lower third molars are unilaterally or bilaterally absent
• lower third molars and incisors may fail to erupt
• a mixture of reactionary and reparative dentin seen in molars
• in 35% of mice up to 3 teeth are absent (hypodontia) and in 52% of mice 4 or more teeth are absent (oligodontia); however the secondary palate is intact and digit duplication is not seen

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