Genetic Mapping of Candidate Gene Influencing the Defect of Tooth in EL Congenic Mice

Abstract

EL/Sea mice have 100% incidence of the defect of the third molars (M3), and are used as an animal model for the study of missing teeth.
We previously have reported that a region between 123.1 Mega base pair (Mbp) and 136.9 Mbp in chromosome 3 was involved in the defect of M3 of EL, and named this gene absence of the third molars (am3).
The purpose of the present study is to narrow the am3 region causing the absence of M3 in EL/Sea mice, and to identify the major candidate gene.
For this reason we generated EL/Sea congenic mice with the am3 region in which the restricted interval of chromosome 3 was replaced by a MSM/Msf-derived homologue.
We also examined the location of chromosomal recombination in the am3 region by newly produced DNA maker.
By comparing genotypes and phenotypes of EL congenic mice, we clearly mapped the am3 locus within an approximately 1000 kbp region between 130.7 Mbp and 131.7 Mbp.
This region includes 5 genes, Lefl, Hadh, Cyp2u1, Sgms2 and Papss 1 as candidate genes for am3.