TITLE:
Lef1 may contribute to agenesis of the third molars in mice
AUTHORS:
Takehiko Shimizu, Takahiro Ichinosawa, Yuri Kiguchi, Fusae Ishida, Takahide Maeda
KEYWORDS:
Hypodontia; Gene Expression; EL Mice
JOURNAL NAME:
Open Journal of Stomatology,
Vol.3 No.5,
July
24,
2013
ABSTRACT: Tooth agenesis is the most common developmental
anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100%
incidence of agenesis of the third molars, may be a good model for the genetic
study of human tooth agenesis. Our previous congenic breeding strategy using EL
mice confined a major locus for agenesis of M3, designated am3, within an
approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains
five known genes; Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate
for am3 among the five genes using
real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and
control mice were dissected out, and total RNA was extracted. In real-time PCR
analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early
tooth development, was observed in M3 of EL mice. In addition, a significantly
low level of expression of Fgf4,
which is a direct transcriptional target for LEF1 in early tooth development,
was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis
of EL mice may be a low level of Lef1
expression in M3 in the bud stage of EL mice.